ORM 之 Dapper

/*

License: http://www.apache.org/licenses/LICENSE-2.0

Home page: http://code.google.com/p/dapper-dot-net/

Note: to build on C# 3.0 + .NET 3.5, include the CSHARP30 compiler symbol (and yes,

I know the difference between language and runtime versions; this is a compromise).

*/

using System;

using System.Collections;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Linq;

using System.Reflection;

using System.Reflection.Emit;

using System.Text.RegularExpressions;

using System.Threading;

namespace Dapper

{

/// <summary>

/// Dapper, a light weight object mapper for ADO.NET

/// </summary>

public static partial class SqlMapper

{

/// <summary>

/// Implement this interface to pass an arbitrary db specific set of parameters to Dapper

/// </summary>

public interface IDynamicParameters

{

/// <summary>

/// Add all the parameters needed to the command just before it executes

/// </summary>

/// <param name="command">The raw command prior to execution</param>

/// <param name="identity">Information about the query</param>

void AddParameters(IDbCommand command, Identity identity);

}

static Link<Type, Action<IDbCommand, bool>> bindByNameCache;

static Action<IDbCommand, bool> GetBindByName(Type commandType)

{

if (commandType == null) return null; // GIGO

Action<IDbCommand, bool> action;

if (Link<Type, Action<IDbCommand, bool>>.TryGet(bindByNameCache, commandType, out action))

{

return action;

}

var prop = commandType.GetProperty("BindByName", BindingFlags.Public | BindingFlags.Instance);

action = null;

ParameterInfo[] indexers;

MethodInfo setter;

if (prop != null && prop.CanWrite && prop.PropertyType == typeof(bool)

&& ((indexers = prop.GetIndexParameters()) == null || indexers.Length == 0)

&& (setter = prop.GetSetMethod()) != null

)

{

var method = new DynamicMethod(commandType.Name + "_BindByName", null, new Type[] { typeof(IDbCommand), typeof(bool) });

var il = method.GetILGenerator();

il.Emit(OpCodes.Ldarg_0);

il.Emit(OpCodes.Castclass, commandType);

il.Emit(OpCodes.Ldarg_1);

il.EmitCall(OpCodes.Callvirt, setter, null);

il.Emit(OpCodes.Ret);

action = (Action<IDbCommand, bool>)method.CreateDelegate(typeof(Action<IDbCommand, bool>));

}

// cache it

Link<Type, Action<IDbCommand, bool>>.TryAdd(ref bindByNameCache, commandType, ref action);

return action;

}

/// <summary>

/// This is a micro-cache; suitable when the number of terms is controllable (a few hundred, for example),

/// and strictly append-only; you cannot change existing values. All key matches are on **REFERENCE**

/// equality. The type is fully thread-safe.

/// </summary>

class Link<TKey, TValue> where TKey : class

{

public static bool TryGet(Link<TKey, TValue> link, TKey key, out TValue value)

{

while (link != null)

{

if ((object)key == (object)link.Key)

{

value = link.Value;

return true;

}

link = link.Tail;

}

value = default(TValue);

return false;

}

public static bool TryAdd(ref Link<TKey, TValue> head, TKey key, ref TValue value)

{

bool tryAgain;

do

{

var snapshot = Interlocked.CompareExchange(ref head, null, null);

TValue found;

if (TryGet(snapshot, key, out found))

{ // existing match; report the existing value instead

value = found;

return false;

}

var newNode = new Link<TKey, TValue>(key, value, snapshot);

// did somebody move our cheese?

tryAgain = Interlocked.CompareExchange(ref head, newNode, snapshot) != snapshot;

} while (tryAgain);

return true;

}

private Link(TKey key, TValue value, Link<TKey, TValue> tail)

{

Key = key;

Value = value;

Tail = tail;

}

public TKey Key { get; private set; }

public TValue Value { get; private set; }

public Link<TKey, TValue> Tail { get; private set; }

}

class CacheInfo

{

public Func<IDataReader, object> Deserializer { get; set; }

public Func<IDataReader, object>[] OtherDeserializers { get; set; }

public Action<IDbCommand, object> ParamReader { get; set; }

private int hitCount;

public int GetHitCount() { return Interlocked.CompareExchange(ref hitCount, 0, 0); }

public void RecordHit() { Interlocked.Increment(ref hitCount); }

}

/// <summary>

/// Called if the query cache is purged via PurgeQueryCache

/// </summary>

public static event EventHandler QueryCachePurged;

private static void OnQueryCachePurged()

{

var handler = QueryCachePurged;

if (handler != null) handler(null, EventArgs.Empty);

}

#if CSHARP30

private static readonly Dictionary<Identity, CacheInfo> _queryCache = new Dictionary<Identity, CacheInfo>();

// note: conflicts between readers and writers are so short-lived that it isn't worth the overhead of

// ReaderWriterLockSlim etc; a simple lock is faster

private static void SetQueryCache(Identity key, CacheInfo value)

{

lock (_queryCache) { _queryCache[key] = value; }

}

private static bool TryGetQueryCache(Identity key, out CacheInfo value)

{

lock (_queryCache) { return _queryCache.TryGetValue(key, out value); }

}

public static void PurgeQueryCache()

{

lock (_queryCache)

{

_queryCache.Clear();

}

OnQueryCachePurged();

}

#else

static readonly System.Collections.Concurrent.ConcurrentDictionary<Identity, CacheInfo> _queryCache = new System.Collections.Concurrent.ConcurrentDictionary<Identity, CacheInfo>();

private static void SetQueryCache(Identity key, CacheInfo value)

{

if(Interlocked.Increment(ref collect)==COLLECT_PER_ITEMS)

{

CollectCacheGarbage();

}

_queryCache[key] = value;

}

private static void CollectCacheGarbage()

{

try

{

foreach (var pair in _queryCache)

{

if (pair.Value.GetHitCount() <= COLLECT_HIT_COUNT_MIN)

{

CacheInfo cache;

_queryCache.TryRemove(pair.Key, out cache);

}

}

}

finally

{

Interlocked.Exchange(ref collect, 0);

}

}

private const int COLLECT_PER_ITEMS = 1000, COLLECT_HIT_COUNT_MIN = 0;

private static int collect;

private static bool TryGetQueryCache(Identity key, out CacheInfo value)

{

if(_queryCache.TryGetValue(key, out value))

{

value.RecordHit();

return true;

}

value = null;

return false;

}

/// <summary>

/// Purge the query cache

/// </summary>

public static void PurgeQueryCache()

{

_queryCache.Clear();

OnQueryCachePurged();

}

/// <summary>

/// Return a count of all the cached queries by dapper

/// </summary>

/// <returns></returns>

public static int GetCachedSQLCount()

{

return _queryCache.Count;

}

/// <summary>

/// Return a list of all the queries cached by dapper

/// </summary>

/// <param name="ignoreHitCountAbove"></param>

/// <returns></returns>

public static IEnumerable<Tuple<string, string, int>> GetCachedSQL(int ignoreHitCountAbove = int.MaxValue)

{

var data = _queryCache.Select(pair => Tuple.Create(pair.Key.connectionString, pair.Key.sql, pair.Value.GetHitCount()));

if (ignoreHitCountAbove < int.MaxValue) data = data.Where(tuple => tuple.Item3 <= ignoreHitCountAbove);

return data;

}

/// <summary>

/// Deep diagnostics only: find any hash collisions in the cache

/// </summary>

/// <returns></returns>

public static IEnumerable<Tuple<int,int>> GetHashCollissions()

{

var counts = new Dictionary<int, int>();

foreach(var key in _queryCache.Keys)

{

int count;

if(!counts.TryGetValue(key.hashCode, out count))

{

counts.Add(key.hashCode, 1);

} else

{

counts[key.hashCode] = count + 1;

}

}

return from pair in counts

where pair.Value > 1

select Tuple.Create(pair.Key, pair.Value);

}

#endif

static readonly Dictionary<Type, DbType> typeMap;

static SqlMapper()

{

typeMap = new Dictionary<Type, DbType>();

typeMap[typeof(byte)] = DbType.Byte;

typeMap[typeof(sbyte)] = DbType.SByte;

typeMap[typeof(short)] = DbType.Int16;

typeMap[typeof(ushort)] = DbType.UInt16;

typeMap[typeof(int)] = DbType.Int32;

typeMap[typeof(uint)] = DbType.UInt32;

typeMap[typeof(long)] = DbType.Int64;

typeMap[typeof(ulong)] = DbType.UInt64;

typeMap[typeof(float)] = DbType.Single;

typeMap[typeof(double)] = DbType.Double;

typeMap[typeof(decimal)] = DbType.Decimal;

typeMap[typeof(bool)] = DbType.Boolean;

typeMap[typeof(string)] = DbType.String;

typeMap[typeof(char)] = DbType.StringFixedLength;

typeMap[typeof(Guid)] = DbType.Guid;

typeMap[typeof(DateTime)] = DbType.DateTime;

typeMap[typeof(DateTimeOffset)] = DbType.DateTimeOffset;

typeMap[typeof(byte[])] = DbType.Binary;

typeMap[typeof(byte?)] = DbType.Byte;

typeMap[typeof(sbyte?)] = DbType.SByte;

typeMap[typeof(short?)] = DbType.Int16;

typeMap[typeof(ushort?)] = DbType.UInt16;

typeMap[typeof(int?)] = DbType.Int32;

typeMap[typeof(uint?)] = DbType.UInt32;

typeMap[typeof(long?)] = DbType.Int64;

typeMap[typeof(ulong?)] = DbType.UInt64;

typeMap[typeof(float?)] = DbType.Single;

typeMap[typeof(double?)] = DbType.Double;

typeMap[typeof(decimal?)] = DbType.Decimal;

typeMap[typeof(bool?)] = DbType.Boolean;

typeMap[typeof(char?)] = DbType.StringFixedLength;

typeMap[typeof(Guid?)] = DbType.Guid;

typeMap[typeof(DateTime?)] = DbType.DateTime;

typeMap[typeof(DateTimeOffset?)] = DbType.DateTimeOffset;

}

private const string LinqBinary = "System.Data.Linq.Binary";

private static DbType LookupDbType(Type type, string name)

{

DbType dbType;

var nullUnderlyingType = Nullable.GetUnderlyingType(type);

if (nullUnderlyingType != null) type = nullUnderlyingType;

if (type.IsEnum)

{

type = Enum.GetUnderlyingType(type);

}

if (typeMap.TryGetValue(type, out dbType))

{

return dbType;

}

if (type.FullName == LinqBinary)

{

return DbType.Binary;

}

if (typeof(IEnumerable).IsAssignableFrom(type))

{

// use xml to denote its a list, hacky but will work on any DB

return DbType.Xml;

}

throw new NotSupportedException(string.Format("The member {0} of type {1} cannot be used as a parameter value", name, type));

}

/// <summary>

/// Identity of a cached query in Dapper, used for extensability

/// </summary>

public class Identity : IEquatable<Identity>

{

internal Identity ForGrid(Type primaryType, int gridIndex)

{

return new Identity(sql, commandType, connectionString, primaryType, parametersType, null, gridIndex);

}

internal Identity ForGrid(Type primaryType, Type[] otherTypes, int gridIndex)

{

return new Identity(sql, commandType, connectionString, primaryType, parametersType, otherTypes, gridIndex);

}

/// <summary>

/// Create an identity for use with DynamicParameters, internal use only

/// </summary>

/// <param name="type"></param>

/// <returns></returns>

public Identity ForDynamicParameters(Type type)

{

return new Identity(sql, commandType, connectionString, this.type ,type, null, -1);

}

internal Identity(string sql, CommandType? commandType, IDbConnection connection, Type type, Type parametersType, Type[] otherTypes)

: this(sql, commandType, connection.ConnectionString, type, parametersType, otherTypes, 0)

{ }

private Identity(string sql, CommandType? commandType, string connectionString, Type type, Type parametersType, Type[] otherTypes, int gridIndex)

{

this.sql = sql;

this.commandType = commandType;

this.connectionString = connectionString;

this.type = type;

this.parametersType = parametersType;

this.gridIndex = gridIndex;

unchecked

{

hashCode = 17; // we *know* we are using this in a dictionary, so pre-compute this

hashCode = hashCode * 23 + commandType.GetHashCode();

hashCode = hashCode * 23 + gridIndex.GetHashCode();

hashCode = hashCode * 23 + (sql == null ? 0 : sql.GetHashCode());

hashCode = hashCode * 23 + (type == null ? 0 : type.GetHashCode());

if (otherTypes != null)

{

foreach (var t in otherTypes)

{

hashCode = hashCode * 23 + (t == null ? 0 : t.GetHashCode());

}

}

hashCode = hashCode * 23 + (connectionString == null ? 0 : connectionString.GetHashCode());

hashCode = hashCode * 23 + (parametersType == null ? 0 : parametersType.GetHashCode());

}

}

/// <summary>

///

/// </summary>

/// <param name="obj"></param>

/// <returns></returns>

public override bool Equals(object obj)

{

return Equals(obj as Identity);

}

/// <summary>

/// The sql

/// </summary>

public readonly string sql;

/// <summary>

/// The command type

/// </summary>

public readonly CommandType? commandType;

/// <summary>

///

/// </summary>

public readonly int hashCode, gridIndex;

private readonly Type type;

/// <summary>

///

/// </summary>

public readonly string connectionString;

/// <summary>

///

/// </summary>

public readonly Type parametersType;

/// <summary>

///

/// </summary>

/// <returns></returns>

public override int GetHashCode()

{

return hashCode;

}

/// <summary>

/// Compare 2 Identity objects

/// </summary>

/// <param name="other"></param>

/// <returns></returns>

public bool Equals(Identity other)

{

return

other != null &&

gridIndex == other.gridIndex &&

type == other.type &&

sql == other.sql &&

commandType == other.commandType &&

connectionString == other.connectionString &&

parametersType == other.parametersType;

}

}

#if CSHARP30

/// <summary>

/// Execute parameterized SQL

/// </summary>

/// <returns>Number of rows affected</returns>

public static int Execute(this IDbConnection cnn, string sql, object param)

{

return Execute(cnn, sql, param, null, null, null);

}

/// <summary>

/// Executes a query, returning the data typed as per T

/// </summary>

/// <remarks>the dynamic param may seem a bit odd, but this works around a major usability issue in vs, if it is Object vs completion gets annoying. Eg type new <space> get new object</remarks>

/// <returns>A sequence of data of the supplied type; if a basic type (int, string, etc) is queried then the data from the first column in assumed, otherwise an instance is

/// created per row, and a direct column-name===member-name mapping is assumed (case insensitive).

/// </returns>

public static IEnumerable<T> Query<T>(this IDbConnection cnn, string sql, object param)

{

return Query<T>(cnn, sql, param, null, true, null, null);

}

#endif

/// <summary>

/// Execute parameterized SQL

/// </summary>

/// <returns>Number of rows affected</returns>

public static int Execute(

#if CSHARP30

this IDbConnection cnn, string sql, object param, IDbTransaction transaction, int? commandTimeout, CommandType? commandType

#else

this IDbConnection cnn, string sql, dynamic param = null, IDbTransaction transaction = null, int? commandTimeout = null, CommandType? commandType = null

#endif

)

{

IEnumerable multiExec = (object)param as IEnumerable;

Identity identity;

CacheInfo info = null;

if (multiExec != null && !(multiExec is string))

{

bool isFirst = true;

int total = 0;

using (var cmd = SetupCommand(cnn, transaction, sql, null, null, commandTimeout, commandType))

{

string masterSql = null;

foreach (var obj in multiExec)

{

if (isFirst)

{

masterSql = cmd.CommandText;

isFirst = false;

identity = new Identity(sql, cmd.CommandType, cnn, null, obj.GetType(), null);

info = GetCacheInfo(identity);

}

else

{

cmd.CommandText = masterSql; // because we do magic replaces on "in" etc

cmd.Parameters.Clear(); // current code is Add-tastic

}

info.ParamReader(cmd, obj);

total += cmd.ExecuteNonQuery();

}

}

return total;

}

// nice and simple

if ((object)param != null)

{

identity = new Identity(sql, commandType, cnn, null, (object) param == null ? null : ((object) param).GetType(), null);

info = GetCacheInfo(identity);

}

return ExecuteCommand(cnn, transaction, sql, (object)param == null ? null : info.ParamReader, (object)param, commandTimeout, commandType);

}

#if !CSHARP30

/// <summary>

/// Return a list of dynamic objects, reader is closed after the call

/// </summary>

public static IEnumerable<dynamic> Query(this IDbConnection cnn, string sql, dynamic param = null, IDbTransaction transaction = null, bool buffered = true, int? commandTimeout = null, CommandType? commandType = null)

{

return Query<FastExpando>(cnn, sql, param as object, transaction, buffered, commandTimeout, commandType);

}

#endif

/// <summary>

/// Executes a query, returning the data typed as per T

/// </summary>

/// <remarks>the dynamic param may seem a bit odd, but this works around a major usability issue in vs, if it is Object vs completion gets annoying. Eg type new [space] get new object</remarks>

/// <returns>A sequence of data of the supplied type; if a basic type (int, string, etc) is queried then the data from the first column in assumed, otherwise an instance is

/// created per row, and a direct column-name===member-name mapping is assumed (case insensitive).

/// </returns>

public static IEnumerable<T> Query<T>(

#if CSHARP30

this IDbConnection cnn, string sql, object param, IDbTransaction transaction, bool buffered, int? commandTimeout, CommandType? commandType

#else

this IDbConnection cnn, string sql, dynamic param = null, IDbTransaction transaction = null, bool buffered = true, int? commandTimeout = null, CommandType? commandType = null

#endif

)

{

var data = QueryInternal<T>(cnn, sql, param as object, transaction, commandTimeout, commandType);

return buffered ? data.ToList() : data;

}

/// <summary>

/// Execute a command that returns multiple result sets, and access each in turn

/// </summary>

public static GridReader QueryMultiple(

#if CSHARP30

this IDbConnection cnn, string sql, object param, IDbTransaction transaction, int? commandTimeout, CommandType? commandType

#else

this IDbConnection cnn, string sql, dynamic param = null, IDbTransaction transaction = null, int? commandTimeout = null, CommandType? commandType = null

#endif

)

{

Identity identity = new Identity(sql, commandType, cnn, typeof(GridReader), (object)param == null ? null : ((object)param).GetType(), null);

CacheInfo info = GetCacheInfo(identity);

IDbCommand cmd = null;

IDataReader reader = null;

try

{

cmd = SetupCommand(cnn, transaction, sql, info.ParamReader, (object)param, commandTimeout, commandType);

reader = cmd.ExecuteReader();

return new GridReader(cmd, reader, identity);

}

catch

{

if (reader != null) reader.Dispose();

if (cmd != null) cmd.Dispose();

throw;

}

}

/// <summary>

/// Return a typed list of objects, reader is closed after the call

/// </summary>

private static IEnumerable<T> QueryInternal<T>(this IDbConnection cnn, string sql, object param, IDbTransaction transaction, int? commandTimeout, CommandType? commandType)

{

var identity = new Identity(sql, commandType, cnn, typeof(T), param == null ? null : param.GetType(), null);

var info = GetCacheInfo(identity);

using (var cmd = SetupCommand(cnn, transaction, sql, info.ParamReader, param, commandTimeout, commandType))

{

using (var reader = cmd.ExecuteReader())

{

Func<Func<IDataReader, object>> cacheDeserializer = () =>

{

info.Deserializer = GetDeserializer(typeof(T), reader, 0, -1, false);

SetQueryCache(identity, info);

return info.Deserializer;

};

if (info.Deserializer == null)

{

cacheDeserializer();

}

var deserializer = info.Deserializer;

while (reader.Read())

{

object next;

try

{

next = deserializer(reader);

}

catch (DataException)

{

// give it another shot, in case the underlying schema changed

deserializer = cacheDeserializer();

next = deserializer(reader);

}

yield return (T)next;

}

}

}

}

/// <summary>

/// Maps a query to objects

/// </summary>

/// <typeparam name="TFirst">The first type in the recordset</typeparam>

/// <typeparam name="TSecond">The second type in the recordset</typeparam>

/// <typeparam name="TReturn">The return type</typeparam>

/// <param name="cnn"></param>

/// <param name="sql"></param>

/// <param name="map"></param>

/// <param name="param"></param>

/// <param name="transaction"></param>

/// <param name="buffered"></param>

/// <param name="splitOn">The Field we should split and read the second object from (default: id)</param>

/// <param name="commandTimeout">Number of seconds before command execution timeout</param>

/// <param name="commandType">Is it a stored proc or a batch?</param>

/// <returns></returns>

public static IEnumerable<TReturn> Query<TFirst, TSecond, TReturn>(

#if CSHARP30

this IDbConnection cnn, string sql, Func<TFirst, TSecond, TReturn> map, object param, IDbTransaction transaction, bool buffered, string splitOn, int? commandTimeout, CommandType? commandType

#else

this IDbConnection cnn, string sql, Func<TFirst, TSecond, TReturn> map, dynamic param = null, IDbTransaction transaction = null, bool buffered = true, string splitOn = "Id", int? commandTimeout = null, CommandType? commandType = null

#endif

)

{

return MultiMap<TFirst, TSecond, DontMap, DontMap, DontMap, TReturn>(cnn, sql, map, param as object, transaction, buffered, splitOn, commandTimeout, commandType);

}

/// <summary>

/// Maps a query to objects

/// </summary>

/// <typeparam name="TFirst"></typeparam>

/// <typeparam name="TSecond"></typeparam>

/// <typeparam name="TThird"></typeparam>

/// <typeparam name="TReturn"></typeparam>

/// <param name="cnn"></param>

/// <param name="sql"></param>

/// <param name="map"></param>

/// <param name="param"></param>

/// <param name="transaction"></param>

/// <param name="buffered"></param>

/// <param name="splitOn">The Field we should split and read the second object from (default: id)</param>

/// <param name="commandTimeout">Number of seconds before command execution timeout</param>

/// <param name="commandType"></param>

/// <returns></returns>

public static IEnumerable<TReturn> Query<TFirst, TSecond, TThird, TReturn>(

#if CSHARP30

this IDbConnection cnn, string sql, Func<TFirst, TSecond, TThird, TReturn> map, object param, IDbTransaction transaction, bool buffered, string splitOn, int? commandTimeout, CommandType? commandType

#else

this IDbConnection cnn, string sql, Func<TFirst, TSecond, TThird, TReturn> map, dynamic param = null, IDbTransaction transaction = null, bool buffered = true, string splitOn = "Id", int? commandTimeout = null, CommandType? commandType = null

#endif

)

{

return MultiMap<TFirst, TSecond, TThird, DontMap, DontMap, TReturn>(cnn, sql, map, param as object, transaction, buffered, splitOn, commandTimeout, commandType);

}

/// <summary>

/// Perform a multi mapping query with 4 input parameters

/// </summary>

/// <typeparam name="TFirst"></typeparam>

/// <typeparam name="TSecond"></typeparam>

/// <typeparam name="TThird"></typeparam>

/// <typeparam name="TFourth"></typeparam>

/// <typeparam name="TReturn"></typeparam>

/// <param name="cnn"></param>

/// <param name="sql"></param>

/// <param name="map"></param>

/// <param name="param"></param>

/// <param name="transaction"></param>

/// <param name="buffered"></param>

/// <param name="splitOn"></param>

/// <param name="commandTimeout"></param>

/// <param name="commandType"></param>

/// <returns></returns>

public static IEnumerable<TReturn> Query<TFirst, TSecond, TThird, TFourth, TReturn>(

#if CSHARP30

this IDbConnection cnn, string sql, Func<TFirst, TSecond, TThird, TFourth, TReturn> map, object param, IDbTransaction transaction, bool buffered, string splitOn, int? commandTimeout, CommandType? commandType

#else

this IDbConnection cnn, string sql, Func<TFirst, TSecond, TThird, TFourth, TReturn> map, dynamic param = null, IDbTransaction transaction = null, bool buffered = true, string splitOn = "Id", int? commandTimeout = null, CommandType? commandType = null

#endif

)

{

return MultiMap<TFirst, TSecond, TThird, TFourth, DontMap, TReturn>(cnn, sql, map, param as object, transaction, buffered, splitOn, commandTimeout, commandType);

}

#if !CSHARP30

/// <summary>

/// Perform a multi mapping query with 5 input parameters

/// </summary>

/// <typeparam name="TFirst"></typeparam>

/// <typeparam name="TSecond"></typeparam>

/// <typeparam name="TThird"></typeparam>

/// <typeparam name="TFourth"></typeparam>

/// <typeparam name="TFifth"></typeparam>

/// <typeparam name="TReturn"></typeparam>

/// <param name="cnn"></param>

/// <param name="sql"></param>

/// <param name="map"></param>

/// <param name="param"></param>

/// <param name="transaction"></param>

/// <param name="buffered"></param>

/// <param name="splitOn"></param>

/// <param name="commandTimeout"></param>

/// <param name="commandType"></param>

/// <returns></returns>

public static IEnumerable<TReturn> Query<TFirst, TSecond, TThird, TFourth, TFifth, TReturn>(this IDbConnection cnn, string sql, Func<TFirst, TSecond, TThird, TFourth, TFifth, TReturn> map, dynamic param = null, IDbTransaction transaction = null, bool buffered = true, string splitOn = "Id", int? commandTimeout = null, CommandType? commandType = null)

{

return MultiMap<TFirst, TSecond, TThird, TFourth, TFifth, TReturn>(cnn, sql, map, param as object, transaction, buffered, splitOn, commandTimeout, commandType);

}

#endif

class DontMap { }

static IEnumerable<TReturn> MultiMap<TFirst, TSecond, TThird, TFourth, TFifth, TReturn>(

this IDbConnection cnn, string sql, object map, object param, IDbTransaction transaction, bool buffered, string splitOn, int? commandTimeout, CommandType? commandType)

{

var results = MultiMapImpl<TFirst, TSecond, TThird, TFourth, TFifth, TReturn>(cnn, sql, map, param, transaction, splitOn, commandTimeout, commandType, null, null);

return buffered ? results.ToList() : results;

}

static IEnumerable<TReturn> MultiMapImpl<TFirst, TSecond, TThird, TFourth, TFifth, TReturn>(this IDbConnection cnn, string sql, object map, object param, IDbTransaction transaction, string splitOn, int? commandTimeout, CommandType? commandType, IDataReader reader, Identity identity)

{

identity = identity ?? new Identity(sql, commandType, cnn, typeof(TFirst), (object)param == null ? null : ((object)param).GetType(), new[] { typeof(TFirst), typeof(TSecond), typeof(TThird), typeof(TFourth), typeof(TFifth) });

CacheInfo cinfo = GetCacheInfo(identity);

IDbCommand ownedCommand = null;

IDataReader ownedReader = null;

try

{

if (reader == null)

{

ownedCommand = SetupCommand(cnn, transaction, sql, cinfo.ParamReader, (object)param, commandTimeout, commandType);

ownedReader = ownedCommand.ExecuteReader();

reader = ownedReader;

}

Func<IDataReader, object> deserializer = null;

Func<IDataReader, object>[] otherDeserializers = null;

Action cacheDeserializers = () =>

{

var deserializers = GenerateDeserializers(new Type[] { typeof(TFirst), typeof(TSecond), typeof(TThird), typeof(TFourth), typeof(TFifth)}, splitOn, reader);

deserializer = cinfo.Deserializer = deserializers[0];

otherDeserializers = cinfo.OtherDeserializers = deserializers.Skip(1).ToArray();

SetQueryCache(identity, cinfo);

};

if ((deserializer = cinfo.Deserializer) == null || (otherDeserializers = cinfo.OtherDeserializers) == null)

{

cacheDeserializers();

}

Func<IDataReader, TReturn> mapIt = GenerateMapper<TFirst, TSecond, TThird, TFourth, TFifth, TReturn>(deserializer, otherDeserializers, map);

if (mapIt != null)

{

while (reader.Read())

{

TReturn next;

try

{

next = mapIt(reader);

}

catch (DataException)

{

cacheDeserializers();

mapIt = GenerateMapper<TFirst, TSecond, TThird, TFourth, TFifth, TReturn>(deserializer, otherDeserializers, map);

next = mapIt(reader);

}

yield return next;

}

}

}

finally

{

try

{

if (ownedReader != null)

{

ownedReader.Dispose();

}

}

finally

{

if (ownedCommand != null)

{

ownedCommand.Dispose();

}

}

}

}

private static Func<IDataReader, TReturn> GenerateMapper<TFirst, TSecond, TThird, TFourth, TFifth, TReturn>(Func<IDataReader, object> deserializer, Func<IDataReader, object>[] otherDeserializers, object map)

{

switch(otherDeserializers.Length)

{

case 1:

return r => ((Func<TFirst, TSecond, TReturn>)map)((TFirst)deserializer(r), (TSecond)otherDeserializers[0](r));

case 2:

return r => ((Func<TFirst, TSecond, TThird, TReturn>)map)((TFirst)deserializer(r), (TSecond)otherDeserializers[0](r), (TThird)otherDeserializers[1](r));

case 3:

return r => ((Func<TFirst, TSecond, TThird, TFourth, TReturn>)map)((TFirst)deserializer(r), (TSecond)otherDeserializers[0](r), (TThird)otherDeserializers[1](r), (TFourth)otherDeserializers[2](r));

#if !CSHARP30

case 4:

return r => ((Func<TFirst, TSecond, TThird, TFourth, TFifth, TReturn>)map)((TFirst)deserializer(r), (TSecond)otherDeserializers[0](r), (TThird)otherDeserializers[1](r), (TFourth)otherDeserializers[2](r), (TFifth)otherDeserializers[3](r));

#endif

default:

throw new NotSupportedException();

}

}

private static Func<IDataReader, object>[] GenerateDeserializers(Type[] types, string splitOn, IDataReader reader)

{

int current = 0;

var splits = splitOn.Split(',').ToArray();

var splitIndex = 0;

Func<Type, int> nextSplit = type =>

{

var currentSplit = splits[splitIndex];

if (splits.Length > splitIndex + 1)

{

splitIndex++;

}

bool skipFirst = false;

int startingPos = current + 1;

// if our current type has the split, skip the first time you see it.

if (type != typeof(Object))

{

var props = GetSettableProps(type);

var fields = GetSettableFields(type);

foreach (var name in props.Select(p => p.Name).Concat(fields.Select(f => f.Name)))

{

if (string.Equals(name, currentSplit, StringComparison.OrdinalIgnoreCase))

{

skipFirst = true;

startingPos = current;

break;

}

}

}

int pos;

for (pos = startingPos; pos < reader.FieldCount; pos++)

{

// some people like ID some id ... assuming case insensitive splits for now

if (splitOn == "*")

{

break;

}

if (string.Equals(reader.GetName(pos), currentSplit, StringComparison.OrdinalIgnoreCase))

{

if (skipFirst)

{

skipFirst = false;

}

else

{

break;

}

}

}

current = pos;

return pos;

};

var deserializers = new List<Func<IDataReader, object>>();

int split = 0;

bool first = true;

foreach (var type in types)

{

if (type != typeof(DontMap))

{

int next = nextSplit(type);

deserializers.Add(GetDeserializer(type, reader, split, next - split, /* returnNullIfFirstMissing: */ !first));

first = false;

split = next;

}

}

return deserializers.ToArray();

}

private static CacheInfo GetCacheInfo(Identity identity)

{

CacheInfo info;

if (!TryGetQueryCache(identity, out info))

{

info = new CacheInfo();

if (identity.parametersType != null)

{

if (typeof(IDynamicParameters).IsAssignableFrom(identity.parametersType))

{

info.ParamReader = (cmd, obj) => { (obj as IDynamicParameters).AddParameters(cmd,identity); };

}

else

{

info.ParamReader = CreateParamInfoGenerator(identity);

}

}

SetQueryCache(identity, info);

}

return info;

}

private static Func<IDataReader, object> GetDeserializer(Type type, IDataReader reader, int startBound, int length, bool returnNullIfFirstMissing)

{

#if !CSHARP30

// dynamic is passed in as Object ... by c# design

if (type == typeof(object)

|| type == typeof(FastExpando))

{

return GetDynamicDeserializer(reader, startBound, length, returnNullIfFirstMissing);

}

#endif

if (!(typeMap.ContainsKey(type) || type.FullName == LinqBinary))

{

return GetTypeDeserializer(type, reader, startBound, length, returnNullIfFirstMissing);

}

return GetStructDeserializer(type, startBound);

}

#if !CSHARP30

private class FastExpando : System.Dynamic.DynamicObject, IDictionary<string, object>

{

IDictionary<string, object> data;

public static FastExpando Attach(IDictionary<string, object> data)

{

return new FastExpando { data = data };

}

public override bool TrySetMember(System.Dynamic.SetMemberBinder binder, object value)

{

data[binder.Name] = value;

return true;

}

public override bool TryGetMember(System.Dynamic.GetMemberBinder binder, out object result)

{

return data.TryGetValue(binder.Name, out result);

}

public override IEnumerable<string> GetDynamicMemberNames()

{

     return data.Keys;

}

#region IDictionary<string,object> Members

void IDictionary<string, object>.Add(string key, object value)

{

throw new NotImplementedException();

}

bool IDictionary<string, object>.ContainsKey(string key)

{

return data.ContainsKey(key);

}

ICollection<string> IDictionary<string, object>.Keys

{

get { return data.Keys; }

}

bool IDictionary<string, object>.Remove(string key)

{

throw new NotImplementedException();

}

bool IDictionary<string, object>.TryGetValue(string key, out object value)

{

return data.TryGetValue(key, out value);

}

ICollection<object> IDictionary<string, object>.Values

{

get { return data.Values; }

}

object IDictionary<string, object>.this[string key]

{

get

{

return data[key];

}

set

{

if (!data.ContainsKey(key))

{

     throw new NotImplementedException();

}

data[key] = value;

}

}

#endregion

#region ICollection<KeyValuePair<string,object>> Members

void ICollection<KeyValuePair<string, object>>.Add(KeyValuePair<string, object> item)

{

throw new NotImplementedException();

}

void ICollection<KeyValuePair<string, object>>.Clear()

{

throw new NotImplementedException();

}

bool ICollection<KeyValuePair<string, object>>.Contains(KeyValuePair<string, object> item)

{

return data.Contains(item);

}

void ICollection<KeyValuePair<string, object>>.CopyTo(KeyValuePair<string, object>[] array, int arrayIndex)

{

data.CopyTo(array, arrayIndex);

}

int ICollection<KeyValuePair<string, object>>.Count

{

get { return data.Count; }

}

bool ICollection<KeyValuePair<string, object>>.IsReadOnly

{

get { return true; }

}

bool ICollection<KeyValuePair<string, object>>.Remove(KeyValuePair<string, object> item)

{

throw new NotImplementedException();

}

#endregion

#region IEnumerable<KeyValuePair<string,object>> Members

IEnumerator<KeyValuePair<string, object>> IEnumerable<KeyValuePair<string, object>>.GetEnumerator()

{

return data.GetEnumerator();

}

#endregion

#region IEnumerable Members

IEnumerator IEnumerable.GetEnumerator()

{

return data.GetEnumerator();

}

#endregion

}

private static Func<IDataReader, object> GetDynamicDeserializer(IDataRecord reader, int startBound, int length, bool returnNullIfFirstMissing)

{

var fieldCount = reader.FieldCount;

if (length == -1)

{

length = fieldCount - startBound;

}

if (fieldCount <= startBound)

{

throw new ArgumentException("When using the multi-mapping APIs ensure you set the splitOn param if you have keys other than Id", "splitOn");

}

return

r =>

{

IDictionary<string, object> row = new Dictionary<string, object>(length);

for (var i = startBound; i < startBound + length; i++)

{

var tmp = r.GetValue(i);

tmp = tmp == DBNull.Value ? null : tmp;

row[r.GetName(i)] = tmp;

if (returnNullIfFirstMissing && i == startBound && tmp == null)

{

return null;

}

}

//we know this is an object so it will not box

return FastExpando.Attach(row);

};

}

#endif

/// <summary>

/// Internal use only

/// </summary>

/// <param name="value"></param>

/// <returns></returns>

[Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]

[Obsolete("This method is for internal usage only", false)]

public static char ReadChar(object value)

{

if (value == null || value is DBNull) throw new ArgumentNullException("value");

string s = value as string;

if (s == null || s.Length != 1) throw new ArgumentException("A single-character was expected", "value");

return s[0];

}

/// <summary>

/// Internal use only

/// </summary>

[Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]

[Obsolete("This method is for internal usage only", false)]

public static char? ReadNullableChar(object value)

{

if (value == null || value is DBNull) return null;

string s = value as string;

if (s == null || s.Length != 1) throw new ArgumentException("A single-character was expected", "value");

return s[0];

}

/// <summary>

/// Internal use only

/// </summary>

[Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]

[Obsolete("This method is for internal usage only", true)]

public static void PackListParameters(IDbCommand command, string namePrefix, object value)

{

var list = value as IEnumerable;

if (list != null)

{

var arrayParm = command.CreateParameter();

arrayParm.Value = list;

arrayParm.ParameterName = namePrefix;

command.Parameters.Add(arrayParm);

                  

}

return;

}

private static IEnumerable<PropertyInfo> FilterParameters(IEnumerable<PropertyInfo> parameters, string sql)

{

return parameters.Where(p => Regex.IsMatch(sql, "[@:]" + p.Name + "([^a-zA-Z0-9_]+|$)", RegexOptions.IgnoreCase | RegexOptions.Multiline));

}

/// <summary>

/// Internal use only

/// </summary>

public static Action<IDbCommand, object> CreateParamInfoGenerator(Identity identity)

{

Type type = identity.parametersType;

bool filterParams = identity.commandType.GetValueOrDefault(CommandType.Text) == CommandType.Text;

var dm = new DynamicMethod(string.Format("ParamInfo{0}", Guid.NewGuid()), null, new[] { typeof(IDbCommand), typeof(object) }, type, true);

var il = dm.GetILGenerator();

il.DeclareLocal(type); // 0

bool haveInt32Arg1 = false;

il.Emit(OpCodes.Ldarg_1); // stack is now [untyped-param]

il.Emit(OpCodes.Unbox_Any, type); // stack is now [typed-param]

il.Emit(OpCodes.Stloc_0);// stack is now empty

il.Emit(OpCodes.Ldarg_0); // stack is now [command]

il.EmitCall(OpCodes.Callvirt, typeof(IDbCommand).GetProperty("Parameters").GetGetMethod(), null); // stack is now [parameters]

IEnumerable<PropertyInfo> props = type.GetProperties().OrderBy(p => p.Name);

if (filterParams)

{

props = FilterParameters(props, identity.sql);

}

foreach (var prop in props)

{

if (filterParams)

{

if (identity.sql.IndexOf("@" + prop.Name, StringComparison.InvariantCultureIgnoreCase) < 0

&& identity.sql.IndexOf(":" + prop.Name, StringComparison.InvariantCultureIgnoreCase) < 0)

{ // can't see the parameter in the text (even in a comment, etc) - burn it with fire

continue;

}

}

if (prop.PropertyType == typeof(DbString))

{

il.Emit(OpCodes.Ldloc_0); // stack is now [parameters] [typed-param]

il.Emit(OpCodes.Callvirt, prop.GetGetMethod()); // stack is [parameters] [dbstring]

il.Emit(OpCodes.Ldarg_0); // stack is now [parameters] [dbstring] [command]

il.Emit(OpCodes.Ldstr, prop.Name); // stack is now [parameters] [dbstring] [command] [name]

il.EmitCall(OpCodes.Callvirt, typeof(DbString).GetMethod("AddParameter"), null); // stack is now [parameters]

continue;

}

DbType dbType = LookupDbType(prop.PropertyType, prop.Name);

if (dbType == DbType.Xml)

{

// this actually represents special handling for list types;

il.Emit(OpCodes.Ldarg_0); // stack is now [parameters] [command]

il.Emit(OpCodes.Ldstr, prop.Name); // stack is now [parameters] [command] [name]

il.Emit(OpCodes.Ldloc_0); // stack is now [parameters] [command] [name] [typed-param]

il.Emit(OpCodes.Callvirt, prop.GetGetMethod()); // stack is [parameters] [command] [name] [typed-value]

if (prop.PropertyType.IsValueType)

{

il.Emit(OpCodes.Box, prop.PropertyType); // stack is [parameters] [command] [name] [boxed-value]

}

il.EmitCall(OpCodes.Call, typeof(SqlMapper).GetMethod("PackListParameters"), null); // stack is [parameters]

continue;

}

il.Emit(OpCodes.Dup); // stack is now [parameters] [parameters]

il.Emit(OpCodes.Ldarg_0); // stack is now [parameters] [parameters] [command]

il.EmitCall(OpCodes.Callvirt, typeof(IDbCommand).GetMethod("CreateParameter"), null);// stack is now [parameters] [parameters] [parameter]

il.Emit(OpCodes.Dup);// stack is now [parameters] [parameters] [parameter] [parameter]

il.Emit(OpCodes.Ldstr, prop.Name); // stack is now [parameters] [parameters] [parameter] [parameter] [name]

il.EmitCall(OpCodes.Callvirt, typeof(IDataParameter).GetProperty("ParameterName").GetSetMethod(), null);// stack is now [parameters] [parameters] [parameter]

il.Emit(OpCodes.Dup);// stack is now [parameters] [parameters] [parameter] [parameter]

EmitInt32(il, (int)dbType);// stack is now [parameters] [parameters] [parameter] [parameter] [db-type]

il.EmitCall(OpCodes.Callvirt, typeof(IDataParameter).GetProperty("DbType").GetSetMethod(), null);// stack is now [parameters] [parameters] [parameter]

il.Emit(OpCodes.Dup);// stack is now [parameters] [parameters] [parameter] [parameter]

EmitInt32(il, (int)ParameterDirection.Input);// stack is now [parameters] [parameters] [parameter] [parameter] [dir]

il.EmitCall(OpCodes.Callvirt, typeof(IDataParameter).GetProperty("Direction").GetSetMethod(), null);// stack is now [parameters] [parameters] [parameter]

il.Emit(OpCodes.Dup);// stack is now [parameters] [parameters] [parameter] [parameter]

il.Emit(OpCodes.Ldloc_0); // stack is now [parameters] [parameters] [parameter] [parameter] [typed-param]

il.Emit(OpCodes.Callvirt, prop.GetGetMethod()); // stack is [parameters] [parameters] [parameter] [parameter] [typed-value]

bool checkForNull = true;

if (prop.PropertyType.IsValueType)

{

il.Emit(OpCodes.Box, prop.PropertyType); // stack is [parameters] [parameters] [parameter] [parameter] [boxed-value]

if (Nullable.GetUnderlyingType(prop.PropertyType) == null)

{ // struct but not Nullable<T>; boxed value cannot be null

checkForNull = false;

}

}

if (checkForNull)

{

if (dbType == DbType.String && !haveInt32Arg1)

{

il.DeclareLocal(typeof(int));

haveInt32Arg1 = true;

}

// relative stack: [boxed value]

il.Emit(OpCodes.Dup);// relative stack: [boxed value] [boxed value]

Label notNull = il.DefineLabel();

Label? allDone = dbType == DbType.String ? il.DefineLabel() : (Label?)null;

il.Emit(OpCodes.Brtrue_S, notNull);

// relative stack [boxed value = null]

il.Emit(OpCodes.Pop); // relative stack empty

il.Emit(OpCodes.Ldsfld, typeof(DBNull).GetField("Value")); // relative stack [DBNull]

if (dbType == DbType.String)

{

EmitInt32(il, 0);

il.Emit(OpCodes.Stloc_1);

}

if (allDone != null) il.Emit(OpCodes.Br_S, allDone.Value);

il.MarkLabel(notNull);

if (prop.PropertyType == typeof(string))

{

il.Emit(OpCodes.Dup); // [string] [string]

il.EmitCall(OpCodes.Callvirt, typeof(string).GetProperty("Length").GetGetMethod(), null); // [string] [length]

EmitInt32(il, 4000); // [string] [length] [4000]

il.Emit(OpCodes.Cgt); // [string] [0 or 1]

Label isLong = il.DefineLabel(), lenDone = il.DefineLabel();

il.Emit(OpCodes.Brtrue_S, isLong);

EmitInt32(il, 4000); // [string] [4000]

il.Emit(OpCodes.Br_S, lenDone);

il.MarkLabel(isLong);

EmitInt32(il, -1); // [string] [-1]

il.MarkLabel(lenDone);

il.Emit(OpCodes.Stloc_1); // [string]

}

if (prop.PropertyType.FullName == LinqBinary)

{

il.EmitCall(OpCodes.Callvirt, prop.PropertyType.GetMethod("ToArray", BindingFlags.Public | BindingFlags.Instance), null);

}

if (allDone != null) il.MarkLabel(allDone.Value);

// relative stack [boxed value or DBNull]

}

il.EmitCall(OpCodes.Callvirt, typeof(IDataParameter).GetProperty("Value").GetSetMethod(), null);// stack is now [parameters] [parameters] [parameter]

if (prop.PropertyType == typeof(string))

{

var endOfSize = il.DefineLabel();

// don't set if 0

il.Emit(OpCodes.Ldloc_1); // [parameters] [parameters] [parameter] [size]

il.Emit(OpCodes.Brfalse_S, endOfSize); // [parameters] [parameters] [parameter]

il.Emit(OpCodes.Dup);// stack is now [parameters] [parameters] [parameter] [parameter]

il.Emit(OpCodes.Ldloc_1); // stack is now [parameters] [parameters] [parameter] [parameter] [size]

il.EmitCall(OpCodes.Callvirt, typeof(IDbDataParameter).GetProperty("Size").GetSetMethod(), null);// stack is now [parameters] [parameters] [parameter]

il.MarkLabel(endOfSize);

}

il.EmitCall(OpCodes.Callvirt, typeof(IList).GetMethod("Add"), null); // stack is now [parameters]

il.Emit(OpCodes.Pop); // IList.Add returns the new index (int); we don't care

}

// stack is currently [command]

il.Emit(OpCodes.Pop); // stack is now empty

il.Emit(OpCodes.Ret);

return (Action<IDbCommand, object>)dm.CreateDelegate(typeof(Action<IDbCommand, object>));

}

private static IDbCommand SetupCommand(IDbConnection cnn, IDbTransaction transaction, string sql, Action<IDbCommand, object> paramReader, object obj, int? commandTimeout, CommandType? commandType)

{

var cmd = cnn.CreateCommand();

var bindByName = GetBindByName(cmd.GetType());

if (bindByName != null) bindByName(cmd, true);

cmd.Transaction = transaction;

cmd.CommandText = sql;

if (commandTimeout.HasValue)

cmd.CommandTimeout = commandTimeout.Value;

if (commandType.HasValue)

cmd.CommandType = commandType.Value;

if (paramReader != null)

{

paramReader(cmd, obj);

}

return cmd;

}

private static int ExecuteCommand(IDbConnection cnn, IDbTransaction transaction, string sql, Action<IDbCommand, object> paramReader, object obj, int? commandTimeout, CommandType? commandType)

{

using (var cmd = SetupCommand(cnn, transaction, sql, paramReader, obj, commandTimeout, commandType))

{

return cmd.ExecuteNonQuery();

}

}

private static Func<IDataReader, object> GetStructDeserializer(Type type, int index)

{

// no point using special per-type handling here; it boils down to the same, plus not all are supported anyway (see: SqlDataReader.GetChar - not supported!)

#pragma warning disable 618

if (type == typeof(char))

{ // this *does* need special handling, though

return r => SqlMapper.ReadChar(r.GetValue(index));

}

if (type == typeof(char?))

{

return r => SqlMapper.ReadNullableChar(r.GetValue(index));

}

if (type.FullName == LinqBinary)

{

return r => Activator.CreateInstance(type, r.GetValue(index));

}

#pragma warning restore 618

return r =>

{

var val = r.GetValue(index);

return val is DBNull ? null : val;

};

}

static readonly MethodInfo

enumParse = typeof(Enum).GetMethod("Parse", new Type[] { typeof(Type), typeof(string), typeof(bool) }),

getItem = typeof(IDataRecord).GetProperties(BindingFlags.Instance | BindingFlags.Public)

.Where(p => p.GetIndexParameters().Any() && p.GetIndexParameters()[0].ParameterType == typeof(int))

.Select(p => p.GetGetMethod()).First();

class PropInfo

{

public string Name { get; set; }

public MethodInfo Setter { get; set; }

public Type Type { get; set; }

}

static List<PropInfo> GetSettableProps(Type t)

{

return t

.GetProperties(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance)

.Select(p => new PropInfo

{

Name = p.Name,

Setter = p.DeclaringType == t ?

p.GetSetMethod(true) :

p.DeclaringType.GetProperty(p.Name, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance).GetSetMethod(true),

Type = p.PropertyType

})

.Where(info => info.Setter != null)

.ToList();

}

static List<FieldInfo> GetSettableFields(Type t)

{

return t.GetFields(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance).ToList();

}

/// <summary>

/// Internal use only

/// </summary>

/// <param name="type"></param>

/// <param name="reader"></param>

/// <param name="startBound"></param>

/// <param name="length"></param>

/// <param name="returnNullIfFirstMissing"></param>

/// <returns></returns>

public static Func<IDataReader, object> GetTypeDeserializer(

#if CSHARP30

Type type, IDataReader reader, int startBound, int length, bool returnNullIfFirstMissing

#else

Type type, IDataReader reader, int startBound = 0, int length = -1, bool returnNullIfFirstMissing = false

#endif

)

{

var dm = new DynamicMethod(string.Format("Deserialize{0}", Guid.NewGuid()), typeof(object), new[] { typeof(IDataReader) }, true);

var il = dm.GetILGenerator();

il.DeclareLocal(typeof(int));

il.DeclareLocal(type);

bool haveEnumLocal = false;

il.Emit(OpCodes.Ldc_I4_0);

il.Emit(OpCodes.Stloc_0);

var properties = GetSettableProps(type);

var fields = GetSettableFields(type);

if (length == -1)

{

length = reader.FieldCount - startBound;

}

if (reader.FieldCount <= startBound)

{

throw new ArgumentException("When using the multi-mapping APIs ensure you set the splitOn param if you have keys other than Id", "splitOn");

}

var names = new List<string>();

for (int i = startBound; i < startBound + length; i++)

{

names.Add(reader.GetName(i));

}

var setters = (

from n in names

let prop = properties.FirstOrDefault(p => string.Equals(p.Name, n, StringComparison.Ordinal)) // property case sensitive first

?? properties.FirstOrDefault(p => string.Equals(p.Name, n, StringComparison.OrdinalIgnoreCase)) // property case insensitive second

let field = prop != null ? null : (fields.FirstOrDefault(p => string.Equals(p.Name, n, StringComparison.Ordinal)) // field case sensitive third

?? fields.FirstOrDefault(p => string.Equals(p.Name, n, StringComparison.OrdinalIgnoreCase))) // field case insensitive fourth

select new { Name = n, Property = prop, Field = field }

).ToList();

int index = startBound;

if (type.IsValueType)

{

il.Emit(OpCodes.Ldloca_S, (byte)1);

il.Emit(OpCodes.Initobj, type);

}

else

{

var ctor = type.GetConstructor(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic, null, Type.EmptyTypes, null);

if (ctor == null)

{

throw new InvalidOperationException("A parameterless default constructor is required to allow for dapper materialization");

}

il.Emit(OpCodes.Newobj, ctor);

il.Emit(OpCodes.Stloc_1);

}

il.BeginExceptionBlock();

if(type.IsValueType)

{

il.Emit(OpCodes.Ldloca_S, (byte)1);// [target]

} else

{

il.Emit(OpCodes.Ldloc_1);// [target]

}

// stack is now [target]

bool first = true;

var allDone = il.DefineLabel();

foreach (var item in setters)

{

if (item.Property != null || item.Field != null)

{

il.Emit(OpCodes.Dup); // stack is now [target][target]

Label isDbNullLabel = il.DefineLabel();

Label finishLabel = il.DefineLabel();

il.Emit(OpCodes.Ldarg_0); // stack is now [target][target][reader]

EmitInt32(il, index); // stack is now [target][target][reader][index]

il.Emit(OpCodes.Dup);// stack is now [target][target][reader][index][index]

il.Emit(OpCodes.Stloc_0);// stack is now [target][target][reader][index]

il.Emit(OpCodes.Callvirt, getItem); // stack is now [target][target][value-as-object]

Type memberType = item.Property != null ? item.Property.Type : item.Field.FieldType;

if (memberType == typeof(char) || memberType == typeof(char?))

{

il.EmitCall(OpCodes.Call, typeof(SqlMapper).GetMethod(

memberType == typeof(char) ? "ReadChar" : "ReadNullableChar", BindingFlags.Static | BindingFlags.Public), null); // stack is now [target][target][typed-value]

}

else

{

il.Emit(OpCodes.Dup); // stack is now [target][target][value][value]

il.Emit(OpCodes.Isinst, typeof(DBNull)); // stack is now [target][target][value-as-object][DBNull or null]

il.Emit(OpCodes.Brtrue_S, isDbNullLabel); // stack is now [target][target][value-as-object]

// unbox nullable enums as the primitive, i.e. byte etc

var nullUnderlyingType = Nullable.GetUnderlyingType(memberType);

var unboxType = nullUnderlyingType != null && nullUnderlyingType.IsEnum ? nullUnderlyingType : memberType;

if (unboxType.IsEnum)

{

if (!haveEnumLocal)

{

il.DeclareLocal(typeof(string));

haveEnumLocal = true;

}

Label isNotString = il.DefineLabel();

il.Emit(OpCodes.Dup); // stack is now [target][target][value][value]

il.Emit(OpCodes.Isinst, typeof(string)); // stack is now [target][target][value-as-object][string or null]

il.Emit(OpCodes.Dup);// stack is now [target][target][value-as-object][string or null][string or null]

il.Emit(OpCodes.Stloc_2); // stack is now [target][target][value-as-object][string or null]

il.Emit(OpCodes.Brfalse_S, isNotString); // stack is now [target][target][value-as-object]

il.Emit(OpCodes.Pop); // stack is now [target][target]

il.Emit(OpCodes.Ldtoken, unboxType); // stack is now [target][target][enum-type-token]

il.EmitCall(OpCodes.Call, typeof(Type).GetMethod("GetTypeFromHandle"), null);// stack is now [target][target][enum-type]

il.Emit(OpCodes.Ldloc_2); // stack is now [target][target][enum-type][string]

il.Emit(OpCodes.Ldc_I4_1); // stack is now [target][target][enum-type][string][true]

il.EmitCall(OpCodes.Call, enumParse, null); // stack is now [target][target][enum-as-object]

il.Emit(OpCodes.Unbox_Any, unboxType); // stack is now [target][target][typed-value]

if (nullUnderlyingType != null)

{

il.Emit(OpCodes.Newobj, memberType.GetConstructor(new[] { nullUnderlyingType }));

}

if (item.Property != null)

{

il.Emit(OpCodes.Callvirt, item.Property.Setter); // stack is now [target]

}

else

{

il.Emit(OpCodes.Stfld, item.Field); // stack is now [target]

}

il.Emit(OpCodes.Br_S, finishLabel);

il.MarkLabel(isNotString);

}

if (memberType.FullName == LinqBinary)

{

il.Emit(OpCodes.Unbox_Any, typeof(byte[])); // stack is now [target][target][byte-array]

il.Emit(OpCodes.Newobj, memberType.GetConstructor(new Type[] { typeof(byte[]) }));// stack is now [target][target][binary]

}

else

{

il.Emit(OpCodes.Unbox_Any, unboxType); // stack is now [target][target][typed-value]

}

if (nullUnderlyingType != null && nullUnderlyingType.IsEnum)

{

il.Emit(OpCodes.Newobj, memberType.GetConstructor(new[] { nullUnderlyingType }));

}

}

if (item.Property != null)

{

if (type.IsValueType)

{

il.Emit(OpCodes.Call, item.Property.Setter); // stack is now [target]

}

else

{

il.Emit(OpCodes.Callvirt, item.Property.Setter); // stack is now [target]

}

}

else

{

il.Emit(OpCodes.Stfld, item.Field); // stack is now [target]

}

il.Emit(OpCodes.Br_S, finishLabel); // stack is now [target]

il.MarkLabel(isDbNullLabel); // incoming stack: [target][target][value]

il.Emit(OpCodes.Pop); // stack is now [target][target]

il.Emit(OpCodes.Pop); // stack is now [target]

if (first && returnNullIfFirstMissing)

{

il.Emit(OpCodes.Pop);

il.Emit(OpCodes.Ldnull); // stack is now [null]

il.Emit(OpCodes.Stloc_1);

il.Emit(OpCodes.Br, allDone);

}

il.MarkLabel(finishLabel);

}

first = false;

index += 1;

}

if (type.IsValueType)

{

il.Emit(OpCodes.Pop);

}

else

{

il.Emit(OpCodes.Stloc_1); // stack is empty

}

il.MarkLabel(allDone);

il.BeginCatchBlock(typeof(Exception)); // stack is Exception

il.Emit(OpCodes.Ldloc_0); // stack is Exception, index

il.Emit(OpCodes.Ldarg_0); // stack is Exception, index, reader

il.EmitCall(OpCodes.Call, typeof(SqlMapper).GetMethod("ThrowDataException"), null);

il.EndExceptionBlock();

il.Emit(OpCodes.Ldloc_1); // stack is [rval]

if(type.IsValueType)

{

il.Emit(OpCodes.Box, type);

}

il.Emit(OpCodes.Ret);

return (Func<IDataReader, object>)dm.CreateDelegate(typeof(Func<IDataReader,object>));

}

/// <summary>

/// Throws a data exception, only used internally

/// </summary>

/// <param name="ex"></param>

/// <param name="index"></param>

/// <param name="reader"></param>

public static void ThrowDataException(Exception ex, int index, IDataReader reader)

{

string name = "(n/a)", value = "(n/a)";

if (reader != null && index >= 0 && index < reader.FieldCount)

{

name = reader.GetName(index);

object val = reader.GetValue(index);

if (val == null || val is DBNull)

{

value = "<null>";

}

else

{

value = Convert.ToString(val) + " - " + Type.GetTypeCode(val.GetType());

}

}

throw new DataException(string.Format("Error parsing column {0} ({1}={2})", index, name, value), ex);

}

private static void EmitInt32(ILGenerator il, int value)

{

switch (value)

{

case -1: il.Emit(OpCodes.Ldc_I4_M1); break;

case 0: il.Emit(OpCodes.Ldc_I4_0); break;

case 1: il.Emit(OpCodes.Ldc_I4_1); break;

case 2: il.Emit(OpCodes.Ldc_I4_2); break;

case 3: il.Emit(OpCodes.Ldc_I4_3); break;

case 4: il.Emit(OpCodes.Ldc_I4_4); break;

case 5: il.Emit(OpCodes.Ldc_I4_5); break;

case 6: il.Emit(OpCodes.Ldc_I4_6); break;

case 7: il.Emit(OpCodes.Ldc_I4_7); break;

case 8: il.Emit(OpCodes.Ldc_I4_8); break;

default:

if (value >= -128 && value <= 127)

{

il.Emit(OpCodes.Ldc_I4_S, (sbyte)value);

}

else

{

il.Emit(OpCodes.Ldc_I4, value);

}

break;

}

}

/// <summary>

/// The grid reader provides interfaces for reading multiple result sets from a Dapper query

/// </summary>

public class GridReader : IDisposable

{

private IDataReader reader;

private IDbCommand command;

private Identity identity;

internal GridReader(IDbCommand command, IDataReader reader, Identity identity)

{

this.command = command;

this.reader = reader;

this.identity = identity;

}

#if !CSHARP30

/// <summary>

/// Read the next grid of results, returned as a dynamic object

/// </summary>

public IEnumerable<dynamic> Read()

{

return Read<FastExpando>();

}

#endif

/// <summary>

/// Read the next grid of results

/// </summary>

public IEnumerable<T> Read<T>()

{

if (reader == null) throw new ObjectDisposedException(GetType().Name);

if (consumed) throw new InvalidOperationException("Each grid can only be iterated once");

var typedIdentity = identity.ForGrid(typeof(T), gridIndex);

CacheInfo cache = GetCacheInfo(typedIdentity);

var deserializer = cache.Deserializer;

Func<Func<IDataReader, object>> deserializerGenerator = () =>

{

deserializer = GetDeserializer(typeof(T), reader, 0, -1, false);

cache.Deserializer = deserializer;

return deserializer;

};

if (deserializer == null)

{

deserializer = deserializerGenerator();

}

consumed = true;

return ReadDeferred<T>(gridIndex, deserializer, typedIdentity, deserializerGenerator);

}

private IEnumerable<TReturn> MultiReadInternal<TFirst, TSecond, TThird, TFourth, TFifth, TReturn>(object func, string splitOn)

{

var identity = this.identity.ForGrid(typeof(TReturn), new Type[] {

typeof(TFirst),

typeof(TSecond),

typeof(TThird),

typeof(TFourth),

typeof(TFifth)

}, gridIndex);

try

{

foreach (var r in SqlMapper.MultiMapImpl<TFirst, TSecond, TThird, TFourth, TFifth, TReturn>(null, null, func, null, null, splitOn, null, null, reader, identity))

{

yield return r;

}

}

finally

{

NextResult();

}

}

/// <summary>

/// Read multiple objects from a single recordset on the grid

/// </summary>

/// <typeparam name="TFirst"></typeparam>

/// <typeparam name="TSecond"></typeparam>

/// <typeparam name="TReturn"></typeparam>

/// <param name="func"></param>

/// <param name="splitOn"></param>

/// <returns></returns>

#if CSHARP30

public IEnumerable<TReturn> Read<TFirst, TSecond, TReturn>(Func<TFirst, TSecond, TReturn> func, string splitOn)

#else

public IEnumerable<TReturn> Read<TFirst, TSecond, TReturn>(Func<TFirst, TSecond, TReturn> func, string splitOn = "id")

#endif

{

return MultiReadInternal<TFirst, TSecond, DontMap, DontMap, DontMap, TReturn>(func, splitOn);

}

/// <summary>

/// Read multiple objects from a single recordset on the grid

/// </summary>

/// <typeparam name="TFirst"></typeparam>

/// <typeparam name="TSecond"></typeparam>

/// <typeparam name="TThird"></typeparam>

/// <typeparam name="TReturn"></typeparam>

/// <param name="func"></param>

/// <param name="splitOn"></param>

/// <returns></returns>

#if CSHARP30

public IEnumerable<TReturn> Read<TFirst, TSecond, TThird, TReturn>(Func<TFirst, TSecond, TThird, TReturn> func, string splitOn)

#else

public IEnumerable<TReturn> Read<TFirst, TSecond, TThird, TReturn>(Func<TFirst, TSecond, TThird, TReturn> func, string splitOn = "id")

#endif

{

return MultiReadInternal<TFirst, TSecond, TThird, DontMap, DontMap, TReturn>(func, splitOn);

}

/// <summary>

/// Read multiple objects from a single record set on the grid

/// </summary>

/// <typeparam name="TFirst"></typeparam>

/// <typeparam name="TSecond"></typeparam>

/// <typeparam name="TThird"></typeparam>

/// <typeparam name="TFourth"></typeparam>

/// <typeparam name="TReturn"></typeparam>

/// <param name="func"></param>

/// <param name="splitOn"></param>

/// <returns></returns>

#if CSHARP30

public IEnumerable<TReturn> Read<TFirst, TSecond, TThird, TFourth, TReturn>(Func<TFirst, TSecond, TThird, TFourth, TReturn> func, string splitOn)

#else

public IEnumerable<TReturn> Read<TFirst, TSecond, TThird, TFourth, TReturn>(Func<TFirst, TSecond, TThird, TFourth, TReturn> func, string splitOn = "id")

#endif

{

return MultiReadInternal<TFirst, TSecond, TThird, TFourth, DontMap, TReturn>(func, splitOn);

}

#if !CSHARP30

/// <summary>

/// Read multiple objects from a single record set on the grid

/// </summary>

/// <typeparam name="TFirst"></typeparam>

/// <typeparam name="TSecond"></typeparam>

/// <typeparam name="TThird"></typeparam>

/// <typeparam name="TFourth"></typeparam>

/// <typeparam name="TFifth"></typeparam>

/// <typeparam name="TReturn"></typeparam>

/// <param name="func"></param>

/// <param name="splitOn"></param>

/// <returns></returns>

public IEnumerable<TReturn> Read<TFirst, TSecond, TThird, TFourth, TFifth, TReturn>(Func<TFirst, TSecond, TThird, TFourth, TFifth, TReturn> func, string splitOn = "id")

{

return MultiReadInternal<TFirst, TSecond, TThird, TFourth, TFifth, TReturn>(func, splitOn);

}

#endif

private IEnumerable<T> ReadDeferred<T>(int index, Func<IDataReader, object> deserializer, Identity typedIdentity, Func<Func<IDataReader, object>> deserializerGenerator)

{

try

{

while (index == gridIndex && reader.Read())

{

object next;

try

{

next = deserializer(reader);

}

catch (DataException)

{

deserializer = deserializerGenerator();

next = deserializer(reader);

}

yield return (T)next;

}

}

finally // finally so that First etc progresses things even when multiple rows

{

if (index == gridIndex)

{

NextResult();

}

}

}

private int gridIndex;

private bool consumed;

private void NextResult()

{

if (reader.NextResult())

{

gridIndex++;

consumed = false;

}

else

{

Dispose();

}

}

/// <summary>

/// Dispose the grid, closing and disposing both the underlying reader and command.

/// </summary>

public void Dispose()

{

if (reader != null)

{

reader.Dispose();

reader = null;

}

if (command != null)

{

command.Dispose();

command = null;

}

}

}

}

/// <summary>

/// A bag of parameters that can be passed to the Dapper Query and Execute methods

/// </summary>

public class DynamicParameters : SqlMapper.IDynamicParameters

{

static Dictionary<SqlMapper.Identity, Action<IDbCommand, object>> paramReaderCache = new Dictionary<SqlMapper.Identity, Action<IDbCommand, object>>();

Dictionary<string, ParamInfo> parameters = new Dictionary<string, ParamInfo>();

List<object> templates;

class ParamInfo

{

public string Name { get; set; }

public object Value { get; set; }

public ParameterDirection ParameterDirection { get; set; }

public DbType? DbType { get; set; }

public int? Size { get; set; }

public IDbDataParameter AttachedParam { get; set; }

}

/// <summary>

/// construct a dynamic parameter bag

/// </summary>

public DynamicParameters() { }

/// <summary>

/// construct a dynamic parameter bag

/// </summary>

/// <param name="template">can be an anonymous type of a DynamicParameters bag</param>

public DynamicParameters(object template)

{

if (template != null)

{

AddDynamicParams(template);

}

}

/// <summary>

/// Append a whole object full of params to the dynamic

/// EG: AddParams(new {A = 1, B = 2}) // will add property A and B to the dynamic

/// </summary>

/// <param name="param"></param>

public void AddDynamicParams(

#if CSHARP30

object param

#else

dynamic param

#endif

)

{

object obj = param as object;

if (obj != null)

{

var subDynamic = obj as DynamicParameters;

if (subDynamic == null)

{

templates = templates ?? new List<object>();

templates.Add(obj);

}

else

{

if (subDynamic.parameters != null)

{

foreach (var kvp in subDynamic.parameters)

{

parameters.Add(kvp.Key, kvp.Value);

}

}

if (subDynamic.templates != null)

{

foreach (var t in subDynamic.templates)

{

templates.Add(t);

}

}

}

}

}

/// <summary>

/// Add a parameter to this dynamic parameter list

/// </summary>

/// <param name="name"></param>

/// <param name="value"></param>

/// <param name="dbType"></param>

/// <param name="direction"></param>

/// <param name="size"></param>

public void Add(

#if CSHARP30

string name, object value, DbType? dbType, ParameterDirection? direction, int? size

#else

string name, object value = null, DbType? dbType = null, ParameterDirection? direction = null, int? size = null

#endif

)

{

parameters[Clean(name)] = new ParamInfo() { Name = name, Value = value, ParameterDirection = direction ?? ParameterDirection.Input, DbType = dbType, Size = size };

}

static string Clean(string name)

{

if (!string.IsNullOrEmpty(name))

{

switch (name[0])

{

case '@':

case ':':

case '?':

return name.Substring(1);

}

}

return name;

}

void SqlMapper.IDynamicParameters.AddParameters(IDbCommand command, SqlMapper.Identity identity)

{

if (templates != null)

{

foreach (var template in templates)

{

var newIdent = identity.ForDynamicParameters(template.GetType());

Action<IDbCommand, object> appender;

lock (paramReaderCache)

{

if (!paramReaderCache.TryGetValue(newIdent, out appender))

{

appender = SqlMapper.CreateParamInfoGenerator(newIdent);

paramReaderCache[newIdent] = appender;

}

}

appender(command, template);

}

}

foreach (var param in parameters.Values)

{

string name = Clean(param.Name);

bool add = !command.Parameters.Contains(name);

IDbDataParameter p;

if(add)

{

p = command.CreateParameter();

p.ParameterName = name;

} else

{

p = (IDbDataParameter)command.Parameters[name];

}

var val = param.Value;

p.Value = val ?? DBNull.Value;

p.Direction = param.ParameterDirection;

var s = val as string;

if (s != null)

{

if (s.Length <= 4000)

{

p.Size = 4000;

}

}

if (param.Size != null)

{

p.Size = param.Size.Value;

}

if (param.DbType != null)

{

p.DbType = param.DbType.Value;

}

if (add)

{

command.Parameters.Add(p);

}

param.AttachedParam = p;

}

}

/// <summary>

/// All the names of the param in the bag, use Get to yank them out

/// </summary>

public IEnumerable<string> ParameterNames

{

get

{

return parameters.Select(p => p.Key);

}

}

/// <summary>

/// Get the value of a parameter

/// </summary>

/// <typeparam name="T"></typeparam>

/// <param name="name"></param>

/// <returns>The value, note DBNull.Value is not returned, instead the value is returned as null</returns>

public T Get<T>(string name)

{

var val = parameters[Clean(name)].AttachedParam.Value;

if (val == DBNull.Value)

{

if (default(T) != null)

{

throw new ApplicationException("Attempting to cast a DBNull to a non nullable type!");

}

return default(T);

}

return (T)val;

}

}

/// <summary>

/// This class represents a SQL string, it can be used if you need to denote your parameter is a Char vs VarChar vs nVarChar vs nChar

/// </summary>

public sealed class DbString

{

/// <summary>

/// Create a new DbString

/// </summary>

public DbString() { Length = -1; }

/// <summary>

/// Ansi vs Unicode

/// </summary>

public bool IsAnsi { get; set; }

/// <summary>

/// Fixed length

/// </summary>

public bool IsFixedLength { get; set; }

/// <summary>

/// Length of the string -1 for max

/// </summary>

public int Length { get; set; }

/// <summary>

/// The value of the string

/// </summary>

public string Value { get; set; }

/// <summary>

/// Add the parameter to the command... internal use only

/// </summary>

/// <param name="command"></param>

/// <param name="name"></param>

public void AddParameter(IDbCommand command, string name)

{

if (IsFixedLength && Length == -1)

{

throw new InvalidOperationException("If specifying IsFixedLength, a Length must also be specified");

}

var param = command.CreateParameter();

param.ParameterName = name;

param.Value = (object)Value ?? DBNull.Value;

if (Length == -1 && Value != null && Value.Length <= 4000)

{

param.Size = 4000;

}

else

{

param.Size = Length;

}

param.DbType = IsAnsi ? (IsFixedLength ? DbType.AnsiStringFixedLength : DbType.AnsiString) : (IsFixedLength ? DbType.StringFixedLength : DbType.String);

command.Parameters.Add(param);

}

}

}

原文地址:https://www.cnblogs.com/ayzhanglei/p/3192906.html