feat(Cmake/Database): separate database lib from common (#5334)

* feat(Core/Database): separate databse lib from common

* 1

src/server/database/Database/Transaction.cpp

@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2016+     AzerothCore <www.azerothcore.org>
+ * Copyright (C) 2008-2016 TrinityCore <http://www.trinitycore.org/>
+ * Copyright (C) 2005-2009 MaNGOS <http://getmangos.com/>
+ */
+
+#include "DatabaseEnv.h"
+#include "Transaction.h"
+
+//- Append a raw ad-hoc query to the transaction
+void Transaction::Append(const char* sql)
+{
+    SQLElementData data;
+    data.type = SQL_ELEMENT_RAW;
+    data.element.query = strdup(sql);
+    m_queries.push_back(data);
+}
+
+void Transaction::PAppend(const char* sql, ...)
+{
+    va_list ap;
+    char szQuery [MAX_QUERY_LEN];
+    va_start(ap, sql);
+    vsnprintf(szQuery, MAX_QUERY_LEN, sql, ap);
+    va_end(ap);
+
+    Append(szQuery);
+}
+
+//- Append a prepared statement to the transaction
+void Transaction::Append(PreparedStatement* stmt)
+{
+    SQLElementData data;
+    data.type = SQL_ELEMENT_PREPARED;
+    data.element.stmt = stmt;
+    m_queries.push_back(data);
+}
+
+void Transaction::Cleanup()
+{
+    // This might be called by explicit calls to Cleanup or by the auto-destructor
+    if (_cleanedUp)
+        return;
+
+    while (!m_queries.empty())
+    {
+        SQLElementData const& data = m_queries.front();
+        switch (data.type)
+        {
+            case SQL_ELEMENT_PREPARED:
+                delete data.element.stmt;
+                break;
+            case SQL_ELEMENT_RAW:
+                free((void*)(data.element.query));
+                break;
+        }
+
+        m_queries.pop_front();
+    }
+
+    _cleanedUp = true;
+}
+
+bool TransactionTask::Execute()
+{
+    if (m_conn->ExecuteTransaction(m_trans))
+        return true;
+
+    if (m_conn->GetLastError() == 1213)
+    {
+        uint8 loopBreaker = 5;  // Handle MySQL Errno 1213 without extending deadlock to the core itself
+        for (uint8 i = 0; i < loopBreaker; ++i)
+            if (m_conn->ExecuteTransaction(m_trans))
+                return true;
+    }
+
+    // Clean up now.
+    m_trans->Cleanup();
+
+    return false;
+}