Question

我尝试使用连接到MySQL 5.6.13的Delphi XE3中的dbExpress来执行嵌套事务。

以下是我执行嵌套事务的示例代码：


...

  dbxTransaction := _connection.BeginTransaction(TDBXIsolations.ReadCommitted);


  // just to check if nested is suported
  supportsNestedBol := dbxTransaction.Connection.DatabaseMetaData.SupportsNestedTransactions;


  try
    _sqlQuery.Close;
    _sqlQuery.SQL.Clear;
    _sqlQuery.SQL.Add('INSERT INTO test(cod, name) VALUES(:cod, :name)');
    _sqlQuery.ParamByName('cod').AsInteger := Test.Cod;
    _sqlQuery.ParamByName('name').AsAnsiString := Test.Name;
    _sqlQuery.ExecSQL(False);


    //calls a nested function that has another transaction
    Employee.Save();


    _connection.CommitFreeAndNil(dbxTransaction);
    Result := True;
  except
    on Exc:Exception do
    begin
      _connection.RollBackFreeAndNil(dbxTransaction);
      raise Exc;
      Result := False;
    end;
  end;

...

function Employee.Save():Boolean;
begin
...
  dbxTransaction02 := _connection.BeginTransaction(TDBXIsolations.ReadCommitted);

  try
    _sqlQuery.Close;
    _sqlQuery.SQL.Clear;
    _sqlQuery.SQL.Add('INSERT INTO employee(cod, name) VALUES(:cod, :name)');
    _sqlQuery.ParamByName('cod').AsInteger := Employee.Cod;
    _sqlQuery.ParamByName('name').AsAnsiString := Employee.Name;
    _sqlQuery.ExecSQL(False);
    _connection.CommitFreeAndNil(dbxTransaction02);
    Result := True;
  except
    on Exc:Exception do
    begin
      _connection.RollBackFreeAndNil(dbxTransaction02);
      raise Exc;
      Result := False;
    end;
  end;
end;
...

如果我设置了断点并检查变量supportsNestedBol，则值为False。所以，我不确定是否是连接器＆＃34; libmysql.dll＆＃34;我使用的不支持嵌套交易，或者我是否尝试这样做。

一些帮助？

如何在MySQL中使用Delphi dbExpress组件中的嵌套事务

0 个答案: