Exposing the transaction used in class Database.

This enables to do queries not supported by rainbow within the same transaction

Closes #1944

Author: kbilsted

Dapper.Rainbow/Database.Async.cs

@@ -88,7 +88,7 @@ public Task<IEnumerable<T>> AllAsync() =>
         /// <param name="param">The parameters to use.</param>
         /// <returns>The number of rows affected.</returns>
         public Task<int> ExecuteAsync(string sql, dynamic param = null) =>
-            _connection.ExecuteAsync(sql, param as object, _transaction, _commandTimeout);
+            _connection.ExecuteAsync(sql, param as object, Transaction, _commandTimeout);
 
         /// <summary>
         /// Asynchronously queries the current database.
@@ -98,7 +98,7 @@ public Task<int> ExecuteAsync(string sql, dynamic param = null) =>
         /// <param name="param">The parameters to use.</param>
         /// <returns>An enumerable of <typeparamref name="T"/> for the rows fetched.</returns>
         public Task<IEnumerable<T>> QueryAsync<T>(string sql, dynamic param = null) =>
-            _connection.QueryAsync<T>(sql, param as object, _transaction, _commandTimeout);
+            _connection.QueryAsync<T>(sql, param as object, Transaction, _commandTimeout);
 
         /// <summary>
         /// Asynchronously queries the current database for a single record.
@@ -108,7 +108,7 @@ public Task<IEnumerable<T>> QueryAsync<T>(string sql, dynamic param = null) =>
         /// <param name="param">The parameters to use.</param>
         /// <returns>An enumerable of <typeparamref name="T"/> for the rows fetched.</returns>
         public Task<T> QueryFirstOrDefaultAsync<T>(string sql, dynamic param = null) =>
-            _connection.QueryFirstOrDefaultAsync<T>(sql, param as object, _transaction, _commandTimeout);
+            _connection.QueryFirstOrDefaultAsync<T>(sql, param as object, Transaction, _commandTimeout);
 
         /// <summary>
         /// Perform an asynchronous multi-mapping query with 2 input types. 
@@ -195,7 +195,7 @@ public Task<IEnumerable<TReturn>> QueryAsync<TFirst, TSecond, TThird, TFourth, T
         /// <param name="param">The parameters to use.</param>
         /// <remarks>Note: each row can be accessed via "dynamic", or by casting to an IDictionary&lt;string,object&gt;</remarks>
         public Task<IEnumerable<dynamic>> QueryAsync(string sql, dynamic param = null) =>
-            _connection.QueryAsync(sql, param as object, _transaction);
+            _connection.QueryAsync(sql, param as object, Transaction);
 
         /// <summary>
         /// Execute a command that returns multiple result sets, and access each in turn.

Dapper.Rainbow/Database.cs

@@ -175,7 +175,11 @@ public Table(Database<TDatabase> database, string likelyTableName)
 
         private DbConnection _connection;
         private int _commandTimeout;
-        private DbTransaction _transaction;
+
+        /// <summary>
+        /// Get access to the underlying transaction
+        /// </summary>
+        public DbTransaction Transaction;
 
         /// <summary>
         /// Get underlying database connection.
@@ -215,27 +219,29 @@ internal virtual Action<TDatabase> CreateTableConstructorForTable()
         /// Begins a transaction in this database.
         /// </summary>
         /// <param name="isolation">The isolation level to use.</param>
-        public void BeginTransaction(IsolationLevel isolation = IsolationLevel.ReadCommitted)
+        /// <returns>The transaction created</returns>
+        public DbTransaction BeginTransaction(IsolationLevel isolation = IsolationLevel.ReadCommitted)
         {
-            _transaction = _connection.BeginTransaction(isolation);
+            Transaction = _connection.BeginTransaction(isolation);
+            return Transaction;
         }
 
         /// <summary>
         /// Commits the current transaction in this database.
         /// </summary>
         public void CommitTransaction()
         {
-            _transaction.Commit();
-            _transaction = null;
+            Transaction.Commit();
+            Transaction = null;
         }
 
         /// <summary>
         /// Rolls back the current transaction in this database.
         /// </summary>
         public void RollbackTransaction()
         {
-            _transaction.Rollback();
-            _transaction = null;
+            Transaction.Rollback();
+            Transaction = null;
         }
 
         /// <summary>
@@ -336,7 +342,7 @@ private bool TableExists(string name)
             if (!string.IsNullOrEmpty(schemaName)) builder.Append("TABLE_SCHEMA = @schemaName AND ");
             builder.Append("TABLE_NAME = @name");
 
-            return _connection.Query(builder.ToString(), new { schemaName, name }, _transaction).Count() == 1;
+            return _connection.Query(builder.ToString(), new { schemaName, name }, Transaction).Count() == 1;
         }
 
         /// <summary>
@@ -346,7 +352,7 @@ private bool TableExists(string name)
         /// <param name="param">The parameters to use.</param>
         /// <returns>The number of rows affected.</returns>
         public int Execute(string sql, dynamic param = null) =>
-            _connection.Execute(sql, param as object, _transaction, _commandTimeout);
+            _connection.Execute(sql, param as object, Transaction, _commandTimeout);
 
         /// <summary>
         /// Queries the current database.
@@ -357,7 +363,7 @@ public int Execute(string sql, dynamic param = null) =>
         /// <param name="buffered">Whether to buffer the results.</param>
         /// <returns>An enumerable of <typeparamref name="T"/> for the rows fetched.</returns>
         public IEnumerable<T> Query<T>(string sql, dynamic param = null, bool buffered = true) =>
-            _connection.Query<T>(sql, param as object, _transaction, buffered, _commandTimeout);
+            _connection.Query<T>(sql, param as object, Transaction, buffered, _commandTimeout);
 
         /// <summary>
         /// Queries the current database for a single record.
@@ -367,7 +373,7 @@ public IEnumerable<T> Query<T>(string sql, dynamic param = null, bool buffered =
         /// <param name="param">The parameters to use.</param>
         /// <returns>An enumerable of <typeparamref name="T"/> for the rows fetched.</returns>
         public T QueryFirstOrDefault<T>(string sql, dynamic param = null) =>
-            _connection.QueryFirstOrDefault<T>(sql, param as object, _transaction, _commandTimeout);
+            _connection.QueryFirstOrDefault<T>(sql, param as object, Transaction, _commandTimeout);
 
         /// <summary>
         /// Perform a multi-mapping query with 2 input types. 
@@ -455,7 +461,7 @@ public IEnumerable<TReturn> Query<TFirst, TSecond, TThird, TFourth, TFifth, TRet
         /// <param name="buffered">Whether the results should be buffered in memory.</param>
         /// <remarks>Note: each row can be accessed via "dynamic", or by casting to an IDictionary&lt;string,object&gt;</remarks>
         public IEnumerable<dynamic> Query(string sql, dynamic param = null, bool buffered = true) =>
-            _connection.Query(sql, param as object, _transaction, buffered);
+            _connection.Query(sql, param as object, Transaction, buffered);
 
         /// <summary>
         /// Execute a command that returns multiple result sets, and access each in turn.
@@ -477,7 +483,7 @@ public virtual void Dispose()
             if (connection.State != ConnectionState.Closed)
             {
                 _connection = null;
-                _transaction = null;
+                Transaction = null;
                 connection?.Close();
             }
             GC.SuppressFinalize(this);