From 9ae86e4127930358c333f7f843ca06312e2cba55 Mon Sep 17 00:00:00 2001
From: kiritow <1362050620@qq.com>
Date: Thu, 23 Nov 2017 14:48:10 +0800
Subject: [PATCH] Add Transaction support

---
 MySQLTransaction.cpp | 58 ++++++++++++++++++++++++++++++++++++++++++++
 MySQLTransaction.h   | 26 ++++++++++++++++++++
 2 files changed, 84 insertions(+)
 create mode 100644 MySQLTransaction.cpp
 create mode 100644 MySQLTransaction.h

diff --git a/MySQLTransaction.cpp b/MySQLTransaction.cpp
new file mode 100644
index 0000000..2a43ba1
--- /dev/null
+++ b/MySQLTransaction.cpp
@@ -0,0 +1,58 @@
+#include "MySQLTransaction.h"
+
+Transaction::Transaction(MySQLConn& MySQLConnection) : conn(MySQLConnection)
+{
+    _isReady=false;
+    _operated=false;
+    if(conn.exec("start transaction",nullptr)<0)
+    {
+        /// SQL execute error.
+    }
+    else
+    {
+        _isReady=true;
+    }
+}
+
+Transaction::~Transaction()
+{
+    if(!_operated)
+    {
+        rollback();
+    }
+}
+
+int Transaction::commit()
+{
+    if(_operated) return -2;
+
+    if(conn.exec("commit",nullptr)<0)
+    {
+        return -1;
+    }
+    else
+    {
+        _operated=true;
+        return conn.getAffectedRows();
+    }
+}
+
+int Transaction::rollback()
+{
+    if(_operated) return -2;
+
+    if(conn.exec("rollback",nullptr)<0)
+    {
+        return -1;
+    }
+    else
+    {
+        _operated=true;
+        return conn.getAffectedRows();
+    }
+}
+
+bool Transaction::isReady() const
+{
+    return _isReady;
+}
diff --git a/MySQLTransaction.h b/MySQLTransaction.h
new file mode 100644
index 0000000..b962ff5
--- /dev/null
+++ b/MySQLTransaction.h
@@ -0,0 +1,26 @@
+#include "MySQLWrapper.h"
+
+class Transaction
+{
+public:
+    /// Start Transaction on construct.
+    Transaction(MySQLConn& MySQLConnection);
+
+    /// Rollback transaction on destruct. If commit() or rollback() is called, this function will not execute any sql.
+    ~Transaction();
+
+    /// NOTE: A Transaction can only call commit() or rollback() once, until it calls start commit again.
+    /// Commit transaction. Equals to SQL: COMMIT
+    /// ReturnValue: -1 SQL Error. -2 Operated >=0 Affected Rows
+    int commit();
+    /// Rollback transaction. Equals to SQL: ROLLBACK
+    /// ReturnValue: -1 SQL Error. -2 Operated >=0 Affected Rows
+    int rollback();
+
+    /// Check if a Transaction object is ready. If it is ready, then a transaction has started.
+    bool isReady() const;
+private:
+    MySQLConn& conn;
+    bool _isReady;
+    bool _operated;
+};