diff --git a/Src/Asp.Net/SqlServerTest/Config.cs b/Src/Asp.Net/SqlServerTest/Config.cs
index 95d8f3261..e13992dcb 100644
--- a/Src/Asp.Net/SqlServerTest/Config.cs
+++ b/Src/Asp.Net/SqlServerTest/Config.cs
@@ -11,5 +11,6 @@ namespace OrmTest
         public static string ConnectionString = "server=.;uid=sa;pwd=haosql;database=SQLSUGAR4XTEST";
         public static string ConnectionString2 = "server=.;uid=sa;pwd=haosql;database=sqlsugar4xtest";
         public static string ConnectionString3 = "server=.;uid=sa;pwd=haosql;database=sqlsugar4xtesT";
+        public static string ConnectionString4 = "server=localhost;Database=SqlSugar4xTest;Uid=root;Pwd=haosql";
     }
 }
diff --git a/Src/Asp.Net/SqlServerTest/Demo/Demo1_SqlSugarClient.cs b/Src/Asp.Net/SqlServerTest/Demo/Demo1_SqlSugarClient.cs
new file mode 100644
index 000000000..25aaa43e5
--- /dev/null
+++ b/Src/Asp.Net/SqlServerTest/Demo/Demo1_SqlSugarClient.cs
@@ -0,0 +1,72 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using SqlSugar;
+namespace OrmTest
+{
+    public class Demo1_SqlSugarClient
+    {
+
+        public static void Init()
+        {
+            DistributedTransactionExample();
+        }
+
+        private static void DistributedTransactionExample()
+        {
+            Console.WriteLine("");
+            Console.WriteLine("#### Distributed TransactionExample Start ####");
+            SqlSugarClient db = new SqlSugarClient(new List<ConnectionConfig>()
+            {
+                new ConnectionConfig(){ ConfigId=1, DbType=DbType.SqlServer, ConnectionString=Config.ConnectionString,InitKeyType=InitKeyType.Attribute,IsAutoCloseConnection=true },
+                new ConnectionConfig(){ ConfigId=2, DbType=DbType.MySql, ConnectionString=Config.ConnectionString4 ,InitKeyType=InitKeyType.Attribute ,IsAutoCloseConnection=true}
+            });
+
+            //use first(SqlServer)
+            db.CodeFirst.SetStringDefaultLength(200).InitTables(typeof(Order), typeof(OrderItem));//
+            db.Insertable(new Order() { Name = "order1", CreateTime = DateTime.Now }).ExecuteCommand();
+            Console.WriteLine(db.CurrentConnectionConfig.DbType + ":" + db.Queryable<Order>().Count());
+
+            //use mysql
+            db.ChangeDatabase(it => it.DbType == DbType.MySql);
+            db.CodeFirst.SetStringDefaultLength(200).InitTables(typeof(Order), typeof(OrderItem));
+            db.Insertable(new Order() { Name = "order1", CreateTime = DateTime.Now }).ExecuteCommand();
+            Console.WriteLine(db.CurrentConnectionConfig.DbType + ":" + db.Queryable<Order>().Count());
+
+            //SqlServer
+            db.ChangeDatabase(it => it.DbType == DbType.SqlServer);//use sqlserver
+            try
+            {
+                db.BeginAllTran();
+
+                db.ChangeDatabase(it => it.DbType == DbType.SqlServer);//use sqlserver
+                db.Deleteable<Order>().ExecuteCommand();
+                Console.WriteLine("---Delete all " + db.CurrentConnectionConfig.DbType);
+                Console.WriteLine(db.Queryable<Order>().Count());
+
+                db.ChangeDatabase(it => it.DbType == DbType.MySql);//use mysql
+                db.Deleteable<Order>().ExecuteCommand();
+                Console.WriteLine("---Delete all " + db.CurrentConnectionConfig.DbType);
+                Console.WriteLine(db.Queryable<Order>().Count());
+
+                throw new Exception();
+                db.CommitAllTran();
+            }
+            catch
+            {
+                db.RollbackAllTran();
+                Console.WriteLine("---Roll back");
+                db.ChangeDatabase(it => it.DbType == DbType.SqlServer);//use sqlserver
+                Console.WriteLine(db.CurrentConnectionConfig.DbType);
+                Console.WriteLine(db.Queryable<Order>().Count());
+
+                db.ChangeDatabase(it => it.DbType == DbType.MySql);//use mysql
+                Console.WriteLine(db.CurrentConnectionConfig.DbType);
+                Console.WriteLine(db.Queryable<Order>().Count());
+            }
+
+            Console.WriteLine("#### Distributed TransactionExample End ####");
+        }
+    }
+}
diff --git a/Src/Asp.Net/SqlServerTest/Models/Order.cs b/Src/Asp.Net/SqlServerTest/Models/Order.cs
new file mode 100644
index 000000000..2af24b100
--- /dev/null
+++ b/Src/Asp.Net/SqlServerTest/Models/Order.cs
@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace OrmTest
+{
+
+    public class Order
+    {
+        [SqlSugar.SugarColumn(IsPrimaryKey = true, IsIdentity = true)]
+        public int Id { get; set; }
+
+        public string Name { get; set; }
+        public decimal Price { get; set; }
+        [SqlSugar.SugarColumn(IsNullable =true)]
+        public DateTime CreateTime { get; set; }
+    }
+}
diff --git a/Src/Asp.Net/SqlServerTest/Models/OrderItem.cs b/Src/Asp.Net/SqlServerTest/Models/OrderItem.cs
new file mode 100644
index 000000000..ae3262c7c
--- /dev/null
+++ b/Src/Asp.Net/SqlServerTest/Models/OrderItem.cs
@@ -0,0 +1,18 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace OrmTest
+{
+    [SqlSugar.SugarTable("OrderDetail")]
+    public class OrderItem
+    {
+        [SqlSugar.SugarColumn(IsPrimaryKey =true, IsIdentity =true)]
+        public int ItemId { get; set; }
+        public int OrderId { get; set; }
+        public decimal? Price { get; set; }
+        [SqlSugar.SugarColumn(IsNullable = true)]
+        public DateTime? CreateTime { get; set; }
+    }
+}
diff --git a/Src/Asp.Net/SqlServerTest/Program.cs b/Src/Asp.Net/SqlServerTest/Program.cs
index 04a01e535..071b3c8e0 100644
--- a/Src/Asp.Net/SqlServerTest/Program.cs
+++ b/Src/Asp.Net/SqlServerTest/Program.cs
@@ -10,6 +10,8 @@ namespace OrmTest
         {
             //OldTestMain.Init();
 
+            Demo1_SqlSugarClient.Init();
+
             Console.WriteLine("all successfully.");
             Console.ReadKey();
         }
diff --git a/Src/Asp.Net/SqlServerTest/SqlServerTest.csproj b/Src/Asp.Net/SqlServerTest/SqlServerTest.csproj
index 1e77a51e3..6707bee85 100644
--- a/Src/Asp.Net/SqlServerTest/SqlServerTest.csproj
+++ b/Src/Asp.Net/SqlServerTest/SqlServerTest.csproj
@@ -49,6 +49,9 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Models\Order.cs" />
+    <Compile Include="Models\OrderItem.cs" />
+    <Compile Include="Demo\Demo1_SqlSugarClient.cs" />
     <Compile Include="OldTest\BugTest\Bug2.cs" />
     <Compile Include="OldTest\BugTest\BugModels\AccountsModel.cs" />
     <Compile Include="OldTest\BugTest\BugModels\ClientsModel.cs" />
@@ -100,9 +103,9 @@
     <Compile Include="OldTest\PerformanceTesting\SqlSugarPerformance.cs" />
     <Compile Include="OldTest\T4\SugarTemplate1.cs" />
     <Compile Include="OldTest\T4\SugarTemplate2.cs">
-      <AutoGen>True</AutoGen>
-      <DesignTime>True</DesignTime>
       <DependentUpon>SugarTemplate.tt</DependentUpon>
+      <DesignTime>True</DesignTime>
+      <AutoGen>True</AutoGen>
     </Compile>
     <Compile Include="OldTest\UnitTest\DataTest.cs" />
     <Compile Include="OldTest\UnitTest\Delete.cs" />
@@ -145,6 +148,7 @@
   <ItemGroup>
     <Service Include="{508349B6-6B84-4DF5-91F0-309BEEBAD82D}" />
   </ItemGroup>
+  <ItemGroup />
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.
diff --git a/Src/Asp.Net/SqlSugar/Abstract/AdoProvider/AdoProvider.cs b/Src/Asp.Net/SqlSugar/Abstract/AdoProvider/AdoProvider.cs
index 696f6bafb..d6200aa2f 100644
--- a/Src/Asp.Net/SqlSugar/Abstract/AdoProvider/AdoProvider.cs
+++ b/Src/Asp.Net/SqlSugar/Abstract/AdoProvider/AdoProvider.cs
@@ -57,12 +57,12 @@ namespace SqlSugar
         }
         public virtual int CommandTimeOut { get; set; }
         public virtual CommandType CommandType { get; set; }
-        public virtual bool IsEnableLogEvent {get;set;}
+        public virtual bool IsEnableLogEvent { get; set; }
         public virtual bool IsClearParameters { get; set; }
-        public virtual Action<string, SugarParameter[]> LogEventStarting=> this.Context.CurrentConnectionConfig.AopEvents.OnLogExecuting;
+        public virtual Action<string, SugarParameter[]> LogEventStarting => this.Context.CurrentConnectionConfig.AopEvents.OnLogExecuting;
         public virtual Action<string, SugarParameter[]> LogEventCompleted => this.Context.CurrentConnectionConfig.AopEvents.OnLogExecuted;
         public virtual Func<string, SugarParameter[], KeyValuePair<string, SugarParameter[]>> ProcessingEventStartingSQL => this.Context.CurrentConnectionConfig.AopEvents.OnExecutingChangeSql;
-        protected virtual Func<string,string> FormatSql { get; set; }
+        protected virtual Func<string, string> FormatSql { get; set; }
         public virtual Action<SqlSugarException> ErrorEvent => this.Context.CurrentConnectionConfig.AopEvents.OnError;
         public virtual Action<DiffLogModel> DiffLogEvent => this.Context.CurrentConnectionConfig.AopEvents.OnDiffLogEvent;
         public virtual List<IDbConnection> SlaveConnections { get; set; }
@@ -147,12 +147,14 @@ namespace SqlSugar
         public virtual void BeginTran()
         {
             CheckConnection();
-            this.Transaction = this.Connection.BeginTransaction();
+            if (this.Transaction == null)
+                this.Transaction = this.Connection.BeginTransaction();
         }
         public virtual void BeginTran(IsolationLevel iso)
         {
             CheckConnection();
-            this.Transaction = this.Connection.BeginTransaction(iso);
+            if (this.Transaction == null)
+                this.Transaction = this.Connection.BeginTransaction(iso);
         }
         public virtual void RollbackTran()
         {
@@ -185,7 +187,7 @@ namespace SqlSugar
         #endregion
 
         #region Use
-        public DbResult<bool> UseTran(Action action, Action<Exception> errorCallBack=null)
+        public DbResult<bool> UseTran(Action action, Action<Exception> errorCallBack = null)
         {
             var result = new DbResult<bool>();
             try
@@ -214,7 +216,7 @@ namespace SqlSugar
         {
             Task<DbResult<bool>> result = new Task<DbResult<bool>>(() =>
             {
-                return UseTran(action,errorCallBack);
+                return UseTran(action, errorCallBack);
             });
             TaskStart(result);
             return result;
@@ -249,7 +251,7 @@ namespace SqlSugar
         {
             Task<DbResult<T>> result = new Task<DbResult<T>>(() =>
             {
-                return UseTran(action,errorCallBack);
+                return UseTran(action, errorCallBack);
             });
             TaskStart(result);
             return result;
@@ -297,7 +299,7 @@ namespace SqlSugar
             try
             {
                 InitParameters(ref sql, parameters);
-                if (FormatSql != null) 
+                if (FormatSql != null)
                     sql = FormatSql(sql);
                 SetConnectionStart(sql);
                 if (this.ProcessingEventStartingSQL != null)
@@ -421,7 +423,7 @@ namespace SqlSugar
         {
             try
             {
-                InitParameters(ref sql,parameters);
+                InitParameters(ref sql, parameters);
                 if (FormatSql != null)
                     sql = FormatSql(sql);
                 SetConnectionStart(sql);
@@ -440,7 +442,7 @@ namespace SqlSugar
             {
                 CommandType = CommandType.Text;
                 if (ErrorEvent != null)
-                    ExecuteErrorEvent(sql,parameters,ex);
+                    ExecuteErrorEvent(sql, parameters, ex);
                 throw ex;
             }
             finally
@@ -943,19 +945,22 @@ namespace SqlSugar
         }
         public virtual void ExecuteBefore(string sql, SugarParameter[] parameters)
         {
-            if (this.Context.IsAsyncMethod==false&&this.Context.CurrentConnectionConfig.Debugger != null && this.Context.CurrentConnectionConfig.Debugger.EnableThreadSecurityValidation == true) {
+            if (this.Context.IsAsyncMethod == false && this.Context.CurrentConnectionConfig.Debugger != null && this.Context.CurrentConnectionConfig.Debugger.EnableThreadSecurityValidation == true)
+            {
 
-                var contextId =this.Context.ContextID.ToString();
+                var contextId = this.Context.ContextID.ToString();
                 var processId = Thread.CurrentThread.ManagedThreadId.ToString();
                 var cache = new ReflectionInoCacheService();
                 if (!cache.ContainsKey<string>(contextId))
                 {
                     cache.Add(contextId, processId);
                 }
-                else {
+                else
+                {
                     var cacheValue = cache.Get<string>(contextId);
-                    if (processId != cacheValue) {
-                       throw new SqlSugarException(this.Context,ErrorMessage.GetThrowMessage("Detection of SqlSugarClient cross-threading usage,a thread needs a new one", "检测到声名的SqlSugarClient跨线程使用，请检查是否静态、是否单例、或者IOC配置错误引起的，保证一个线程new出一个对象 ，具本Sql:")+sql,parameters);
+                    if (processId != cacheValue)
+                    {
+                        throw new SqlSugarException(this.Context, ErrorMessage.GetThrowMessage("Detection of SqlSugarClient cross-threading usage,a thread needs a new one", "检测到声名的SqlSugarClient跨线程使用，请检查是否静态、是否单例、或者IOC配置错误引起的，保证一个线程new出一个对象 ，具本Sql:") + sql, parameters);
                     }
                 }
             }
@@ -982,11 +987,12 @@ namespace SqlSugar
             var hasParameter = parameters.HasValue();
             if (hasParameter)
             {
-                foreach (var outputParameter in parameters.Where(it => it.Direction.IsIn(ParameterDirection.Output, ParameterDirection.InputOutput,ParameterDirection.ReturnValue)))
+                foreach (var outputParameter in parameters.Where(it => it.Direction.IsIn(ParameterDirection.Output, ParameterDirection.InputOutput, ParameterDirection.ReturnValue)))
                 {
                     var gobalOutputParamter = this.OutputParameters.FirstOrDefault(it => it.ParameterName == outputParameter.ParameterName);
-                    if (gobalOutputParamter == null) {//Oracle bug
-                        gobalOutputParamter=this.OutputParameters.FirstOrDefault(it => it.ParameterName == outputParameter.ParameterName.TrimStart(outputParameter.ParameterName.First()));
+                    if (gobalOutputParamter == null)
+                    {//Oracle bug
+                        gobalOutputParamter = this.OutputParameters.FirstOrDefault(it => it.ParameterName == outputParameter.ParameterName.TrimStart(outputParameter.ParameterName.First()));
                     }
                     outputParameter.Value = gobalOutputParamter.Value;
                     this.OutputParameters.Remove(gobalOutputParamter);
@@ -1028,12 +1034,12 @@ namespace SqlSugar
         {
             get
             {
-                return this.Context.CurrentConnectionConfig.SlaveConnectionConfigs.HasValue()&& this.IsDisableMasterSlaveSeparation==false;
+                return this.Context.CurrentConnectionConfig.SlaveConnectionConfigs.HasValue() && this.IsDisableMasterSlaveSeparation == false;
             }
         }
         private void SetConnectionStart(string sql)
         {
-            if (this.Transaction==null&&this.IsMasterSlaveSeparation && IsRead(sql))
+            if (this.Transaction == null && this.IsMasterSlaveSeparation && IsRead(sql))
             {
                 if (this.MasterConnection == null)
                 {
@@ -1063,7 +1069,7 @@ namespace SqlSugar
 
         private void SetConnectionEnd(string sql)
         {
-            if (this.IsMasterSlaveSeparation && IsRead(sql)&&this.Transaction==null)
+            if (this.IsMasterSlaveSeparation && IsRead(sql) && this.Transaction == null)
             {
                 this.Connection = this.MasterConnection;
                 this.Context.CurrentConnectionConfig.ConnectionString = this.MasterConnection.ConnectionString;
@@ -1079,9 +1085,9 @@ namespace SqlSugar
 
         private void ExecuteErrorEvent(string sql, SugarParameter[] parameters, Exception ex)
         {
-            ErrorEvent(new SqlSugarException(this.Context,ex, sql, parameters));
+            ErrorEvent(new SqlSugarException(this.Context, ex, sql, parameters));
         }
-        private  void InitParameters(ref string sql, SugarParameter[] parameters)
+        private void InitParameters(ref string sql, SugarParameter[] parameters)
         {
             if (parameters.HasValue())
             {
@@ -1103,7 +1109,7 @@ namespace SqlSugar
                             }
                             if (item.ParameterName.Substring(0, 1) == ":")
                             {
-                                sql = sql.Replace("@"+item.ParameterName.Substring(1), newValues.ToArray().ToJoinSqlInVals());
+                                sql = sql.Replace("@" + item.ParameterName.Substring(1), newValues.ToArray().ToJoinSqlInVals());
                             }
                             sql = sql.Replace(item.ParameterName, newValues.ToArray().ToJoinSqlInVals());
                             item.Value = DBNull.Value;
diff --git a/Src/Asp.Net/SqlSugar/Abstract/CodeFirstProvider/CodeFirstProvider.cs b/Src/Asp.Net/SqlSugar/Abstract/CodeFirstProvider/CodeFirstProvider.cs
index 31d883855..68d5983fa 100644
--- a/Src/Asp.Net/SqlSugar/Abstract/CodeFirstProvider/CodeFirstProvider.cs
+++ b/Src/Asp.Net/SqlSugar/Abstract/CodeFirstProvider/CodeFirstProvider.cs
@@ -12,6 +12,13 @@ namespace SqlSugar
         protected bool IsBackupTable { get; set; }
         protected int MaxBackupDataRows { get; set; }
         protected virtual int DefultLength { get; set; }
+        public CodeFirstProvider()
+        {
+            if (DefultLength == 0)
+            {
+                DefultLength = 255;
+            }
+        }
         #endregion
 
         #region Public methods
@@ -50,15 +57,15 @@ namespace SqlSugar
         }
         public void InitTables<T, T2>()
         {
-            InitTables(typeof(T),typeof(T2));
+            InitTables(typeof(T), typeof(T2));
         }
         public void InitTables<T, T2, T3>()
         {
-            InitTables(typeof(T), typeof(T2),typeof(T3));
+            InitTables(typeof(T), typeof(T2), typeof(T3));
         }
         public void InitTables<T, T2, T3, T4>()
         {
-            InitTables(typeof(T), typeof(T2), typeof(T3),typeof(T4));
+            InitTables(typeof(T), typeof(T2), typeof(T3), typeof(T4));
         }
         public virtual void InitTables(params Type[] entityTypes)
         {
diff --git a/Src/Asp.Net/SqlSugar/Abstract/DbMaintenanceProvider/Methods.cs b/Src/Asp.Net/SqlSugar/Abstract/DbMaintenanceProvider/Methods.cs
index 29cf211d6..b77535970 100644
--- a/Src/Asp.Net/SqlSugar/Abstract/DbMaintenanceProvider/Methods.cs
+++ b/Src/Asp.Net/SqlSugar/Abstract/DbMaintenanceProvider/Methods.cs
@@ -237,7 +237,7 @@ namespace SqlSugar
         }
         public virtual bool AddTableRemark(string tableName, string description)
         {
-            string sql = string.Format(this.AddTableRemarkSql, tableName, description);
+            string sql = string.Format(this.AddTableRemarkSql,this.SqlBuilder.GetTranslationTableName(tableName), description);
             this.Context.Ado.ExecuteCommand(sql);
             return true;
         }
diff --git a/Src/Asp.Net/SqlSugar/Entities/ConnectionConfig.cs b/Src/Asp.Net/SqlSugar/Entities/ConnectionConfig.cs
index 5f38997e8..83ca1cc21 100644
--- a/Src/Asp.Net/SqlSugar/Entities/ConnectionConfig.cs
+++ b/Src/Asp.Net/SqlSugar/Entities/ConnectionConfig.cs
@@ -12,7 +12,7 @@ namespace SqlSugar
         /// <summary>
         /// 
         /// </summary>
-        public string ConfigId { get; set; }
+        public dynamic ConfigId { get; set; }
         /// <summary>
         ///DbType.SqlServer Or Other
         /// </summary>
diff --git a/Src/Asp.Net/SqlSugar/SqlSugarClient.cs b/Src/Asp.Net/SqlSugar/SqlSugarClient.cs
index 9a0da29af..549ad8e7f 100644
--- a/Src/Asp.Net/SqlSugar/SqlSugarClient.cs
+++ b/Src/Asp.Net/SqlSugar/SqlSugarClient.cs
@@ -53,7 +53,7 @@ namespace SqlSugar
         {
             var allConfigs = _AllClients.Select(it => it.ConnectionConfig);
             Check.Exception(!allConfigs.Any(changeExpression), "changeExpression was not found {0}", changeExpression.ToString());
-            InitContext(allConfigs.First(changeExpression));
+            InitTerant(_AllClients.First(it=>it.ConnectionConfig==allConfigs.First(changeExpression)));
             if (this._IsAllTran)
                 this.Ado.BeginTran();
         }