EF_简单的增删改查

EF分为三种code_first,model_first，dabase_first这三种模式，网上的例子有好多，但是用了之后感觉实际中都不是这么用的，此处记录写下来日后用的着了可以快速应用，记录如下：

新建项目添加EF6.2

需要四个东西：

1.表对应的model实例，此例中为： shop_test

2.EF连接数据的对象类，此例中为： EF_DATA_DBCONTEXT

3.数据操作的接口类，此例中为： IRepository

4.数据实际操作类，实现接口IRespository的类，此例中为: DataAccessObject

1.shop_test

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using System.ComponentModel.DataAnnotations.Schema;
using System.ComponentModel.DataAnnotations;

using System.Runtime.Serialization;

namespace EF_TEST
{
[DataContract]
[Serializable]
[Table("shop_test")]
public partial class shop_test
{

[DataMember(Name ="id")]
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int id { get; set; }

[DataMember(Name ="shopname")]
public string shopname { get; set; }

[DataMember(Name ="create_time")]
public DateTime create_time { get; set; }

[DataMember(Name ="test_msg")]
public string test_msg { get; set; }

}
}

2.EF_DATA_DBCONTEXT

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using System.Data.Entity;

namespace EF_TEST
{

//用EF进行连接时需要指定的连接数据库的
class EF_DATA_DBCONTEXT:DbContext
{
public EF_DATA_DBCONTEXT(string contr) : base(contr)
{

}

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
//base.OnModelCreating(modelBuilder);
}

public DbSet<shop_test> shoptests { get; set; }

}
}

3.IRepository

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using System.Linq.Expressions;
using System.Data.Entity;

using System.Data.Entity.Infrastructure;

namespace EF_TEST
{
interface IRepository
{

DbContext CurrentDbContext
{
get;
}

DbEntityEntry<T> Attach<T>(T entity) where T : class;

T Insert<T>(T entity) where T : class;

T Insert<T>(T entity, bool isCommit) where T : class;

void InsertRange<T>(IEnumerable<T> entities) where T : class;

void InsertRange<T>(IEnumerable<T> entities, bool isCommit) where T : class;

void Update<T>(T entity) where T : class;

void Update<T>(T entity, bool isCommit) where T : class;

void UpdateRange<T>(IEnumerable<T> entities) where T : class;

void UpdateRange<T>(IEnumerable<T> entities, bool isCommit) where T : class;

void Delete<T>(T entity) where T : class;

void Delete<T>(T entity, bool isCommit) where T : class;

void DeleteRange<T>(IEnumerable<T> entities) where T : class;

void DeleteRange<T>(IEnumerable<T> entities, bool isCommit) where T : class;

T Find<T>(params object[] keyValues) where T : class;

T Find<T>(object keyValue) where T : class;

List<T> FindAll<T>(Expression<Func<T, bool>> conditions = null) where T : class;

List<T> FindAllByPage<T, S>(Expression<Func<T, bool>> conditions, Expression<Func<T, S>> orderBy, int pageSize, int pageIndex) where T : class;

int SaveChanges();

}
}

4.DataAccessObject

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using System.Data.Entity;
using System.Linq.Expressions;

using System.Data.Entity.Infrastructure;

using System.Data;

namespace EF_TEST
{
class DataAccessObject:IRepository,IDisposable
{

private DbContext _currentDbContext = null;

public DbContext CurrentDbContext
{
get
{
return this._currentDbContext;
}
}

public DataAccessObject(DbContext dbContext)
{
this._currentDbContext = dbContext;
}

public DbEntityEntry<T> Attach<T>(T entity) where T : class
{
DbSet<T> dbSet = this._currentDbContext.Set<T>();
dbSet.Attach(entity);
return this._currentDbContext.Entry<T>(entity);
}

public T Insert<T>(T entity) where T : class
{
return this.Insert<T>(entity, true);
}

public T Insert<T>(T entity, bool isCommit) where T : class
{
this._currentDbContext.Set<T>().Add(entity);
if (isCommit)
{
this._currentDbContext.SaveChanges();
}
return entity;
}

public void InsertRange<T>(IEnumerable<T> entities) where T : class
{
this.InsertRange<T>(entities, true);
}

public void InsertRange<T>(IEnumerable<T> entities, bool isCommit) where T : class
{
this._currentDbContext.Set<T>().AddRange(entities);
if (isCommit)
{
this._currentDbContext.SaveChanges();
}
}

public void Update<T>(T entity) where T : class
{
this.Update<T>(entity, true);
}

public void Update<T>(T entity, bool isCommit) where T : class
{
this._currentDbContext.Set<T>().Attach(entity);
//this._currentDbContext.Entry<T>(entity).set_State(16);
this._currentDbContext.Entry<T>(entity).State = EntityState.Modified;
if (isCommit)
{
this._currentDbContext.SaveChanges();
}
}

public void UpdateRange<T>(IEnumerable<T> entities) where T : class
{
this.UpdateRange<T>(entities, true);
}

public void UpdateRange<T>(IEnumerable<T> entities, bool isCommit) where T : class
{
foreach (T current in entities)
{
this._currentDbContext.Set<T>().Attach(current);
// this._currentDbContext.Entry<T>(current).set_State(16);
this._currentDbContext.Entry<T>(current).State = EntityState.Modified;
}
if (isCommit)
{
this._currentDbContext.SaveChanges();
}
}

public void Delete<T>(T entity) where T : class
{
this.Delete<T>(entity, true);
}

public void Delete<T>(T entity, bool isCommit) where T : class
{
this._currentDbContext.Set<T>().Remove(entity);
if (isCommit)
{
this._currentDbContext.SaveChanges();
}
}

public void DeleteRange<T>(IEnumerable<T> entities) where T : class
{
this.DeleteRange<T>(entities, true);
}

public void DeleteRange<T>(IEnumerable<T> entities, bool isCommit) where T : class
{
this._currentDbContext.Set<T>().RemoveRange(entities);
if (isCommit)
{
this._currentDbContext.SaveChanges();
}
}

public int SaveChanges()
{
return this._currentDbContext.SaveChanges();
}

public T Find<T>(params object[] keyValues) where T : class
{
return this._currentDbContext.Set<T>().Find(keyValues);
}

public T Find<T>(object keyValue) where T : class
{
object[] array = new object[]
{
keyValue
};
return this._currentDbContext.Set<T>().Find(array);
}

public List<T> FindAll<T>(Expression<Func<T, bool>> conditions = null) where T : class
{
List<T> result;
if (conditions == null)
{
result = this._currentDbContext.Set<T>().ToList<T>();
}
else
{
result = this._currentDbContext.Set<T>().Where(conditions).ToList<T>();
}
return result;
}

public List<T> FindAllByPage<T, S>(Expression<Func<T, bool>> conditions, Expression<Func<T, S>> orderBy, int pageSize, int pageIndex) where T : class
{
IQueryable<T> source = (conditions == null) ? this._currentDbContext.Set<T>() : this._currentDbContext.Set<T>().Where(conditions);
return source.OrderByDescending(orderBy).Skip((pageIndex - 1) * pageSize).Take(pageSize).ToList<T>();
}

public void Dispose()
{
this._currentDbContext.Dispose();
}

}
}

控制台程序：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using System.Data.Entity;

using System.Transactions;

namespace EF_TEST
{
class Program
{
static void Main(string[] args)
{

//config中的数据库的连接字符串
string CONSTR = System.Configuration.ConfigurationManager.ConnectionStrings["CONSTR"].ConnectionString;

//EF的DB连接对象
EF_DATA_DBCONTEXT db = new EF_DATA_DBCONTEXT(CONSTR);

//实现的的具体方法
IRepository DB_LINK = new DataAccessObject(db);

//进行的查询操作
List<shop_test> msg = DB_LINK.FindAll<shop_test>(p => p.id >= 0);

Console.WriteLine("查询ID大于0的所有数据");
Console.WriteLine("共查询到的信息行数:{0}--最后一个数据的时间:{1}", msg.Count, msg.Max(u => u.create_time).ToString());

//插入操作
shop_test insert_shop = new shop_test() { shopname="test", test_msg="ss", create_time =DateTime.Now };

using (TransactionScope scope =new TransactionScope() )
{
DB_LINK.Insert<shop_test>(insert_shop,false);

shop_test insert_second = new shop_test() { shopname=insert_shop.shopname, test_msg=insert_shop.test_msg, create_time=DateTime.Now };

DB_LINK.Insert<shop_test>(insert_second, false);

DB_LINK.SaveChanges();

scope.Complete();
}

Console.WriteLine("插入的id:{0}--shopname {1}---test_msg:{2} ---create_time:{2}", insert_shop.id, insert_shop.shopname, insert_shop.test_msg, insert_shop.create_time);

//更新操作
msg = DB_LINK.FindAll<shop_test>(u => u.id > 0);

Console.WriteLine("查询ID大于0的所有数据");
Console.WriteLine("共查询到的信息行数:{0}--最后一个数据的时间:{1}", msg.Count, msg.Max(u => u.create_time));

//更新操作，更新最大时间为当前时间

shop_test update_shop = (from i in msg
let max_time = msg.Max(u => u.create_time)
where i.create_time == max_time
select i
).FirstOrDefault();

update_shop.create_time = DateTime.Now;

DB_LINK.Update<shop_test>(update_shop);

Console.WriteLine("更新的id:{0}--shopname {1}---test_msg:{2} ---create_time:{2}", insert_shop.id, insert_shop.shopname, insert_shop.test_msg, insert_shop.create_time);

//删除操作；
Console.WriteLine("查询ID大于0的所有数据");
Console.WriteLine("共查询到的信息行数:{0}--最后一个数据的时间:{1}", msg.Count, msg.Max(u => u.create_time));

//删除操作删除时间最早的数据
msg = DB_LINK.FindAll<shop_test>(u => u.id > 0);

shop_test delete_shop = (from i in msg
let max_time = msg.Max(u => u.create_time)
where i.create_time == max_time
select i
).FirstOrDefault();

DB_LINK.Delete<shop_test>(delete_shop);

Console.WriteLine("删除的id:{0}--shopname {1}---test_msg:{2} ---create_time:{2}", insert_shop.id, insert_shop.shopname, insert_shop.test_msg, insert_shop.create_time);

Console.WriteLine("查询ID大于0的所有数据");
Console.WriteLine("共查询到的信息行数:{0}--最后一个数据的时间:{1}", msg.Count, msg.Max(u=>u.create_time));

Console.ReadKey();

}
}
}

配置文件，及其数据库的表结构：

CREATE TABLE [dbo].[shop_test](
[id] [INT] IDENTITY(1,1) NOT NULL,
[shopname] [VARCHAR](50) NULL,
[create_time] [DATETIME] NULL,
CONSTRAINT [PK_shop_test] PRIMARY KEY NONCLUSTERED
(
[id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
)