sqlite3 根据实体自动生成建表语句

 
public class BuildSqlTool
    {
        public static string GetCreateTableSql(object t)
        {
            //CREATE TABLE "StructureView2"("Id" INTEGER PRIMARY KEY  AUTOINCREMENT , "IdxNo" VARCHAR, "Name" VARCHAR, "Content" VARCHAR, "Price" FLOAT, "Order" INTEGER)
            string sqlStr = "CREATE TABLE "{0}" ({1})";
            Type type = t.GetType(); 
            PropertyInfo[] pi = type.GetProperties();
            string sqlFormat = ""{0}" {1}";
            string sqlStr2 = "";
            foreach (PropertyInfo p in pi)
            {
               string name=p.Name;
               object[]abc=p.GetCustomAttributes(true);
               if (name.ToLower()=="id")
               {
                   sqlStr2 += string.Format(sqlFormat, "Id", "INTEGER PRIMARY KEY  AUTOINCREMENT");
               }
               else
               {
                   sqlStr2 +=","+string.Format(sqlFormat, name, SqlType(p));
               } 
            }
            return string.Format(sqlStr, GetTableName(type), sqlStr2);
        }

        static string GetTableName(Type type)
        {
            var tableAttr = (TableAttribute)type.GetCustomAttributes(typeof(TableAttribute), true).FirstOrDefault();
            return tableAttr != null ? tableAttr.Name : type.Name;
        }

        static string SqlType(PropertyInfo p)
        {
            Type clrType = p.PropertyType;
            if (clrType == typeof(Boolean) || clrType == typeof(Byte) || clrType == typeof(UInt16) || clrType == typeof(SByte) || clrType == typeof(Int16) || clrType == typeof(Int32))
            {
                return "integer";
            }
            else if (clrType == typeof(UInt32) || clrType == typeof(Int64))
            {
                return "bigint";
            }
            else if (clrType == typeof(Single) || clrType == typeof(Double) || clrType == typeof(Decimal))
            {
                return "float";
            }
            else if (clrType == typeof(String))
            {
                return "varchar";
                //int len = MaxStringLength(p);
                //return "varchar(" + len + ")";
            }
            else if (clrType == typeof(DateTime))
            {
                return "datetime"; 
            }
            else if (clrType.IsEnum)
            { 
                return "integer";
            }
            else if (clrType == typeof(byte[]))
            {
                return "blob";
            }
            else if (clrType == typeof(Guid))
            {
                return "varchar(36)";
            }
            else
            {
                throw new NotSupportedException("Don't know about " + clrType);
            }
        }
         
        int MaxStringLength(PropertyInfo p)
        {
            var attrs = p.GetCustomAttributes(typeof(MaxLengthAttribute), true);
            if (attrs.Length > 0)
            {
                return ((MaxLengthAttribute)attrs[0]).Value;
            }
            else
            {
                return 140;
            }
        }
    }

主要目的是为了减少见表,同理,可自动生成orm的sql

使用范例

// 获取当前程序集
Assembly assembly = Assembly.GetExecutingAssembly();
// 创建类的实例,返回为 object 类型类的完全限定名(即包括命名空间)
object obj = assembly.CreateInstance("ConstructionBudget.Model.VModel1");
string sql = BuildSqlTool.GetCreateTableSql(obj);

原文地址:https://www.cnblogs.com/wyxy2005/p/3679492.html