mysql + unidac 使用事务例子
mysql + unidac 使用事务例子
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mysql + unidac 使用事务例子
备注：mysql必须是使用innoDB引擎才支持事务功能，否则以下事务相关代码将失效。//SQL SERVER和Oracle还没试，明天回公司试了再发代码。procedure TForm1.btn1Click(Sender: TObject);
var
i, j: Integer;
begin
UniConnection1.Connect;
try
try
UniTransaction1.Connections[0].StartTransaction;
UniQuery1.Params.Clear;
UniQuery1.SQL.Text := ‘insert into user (username,password)values(:username, :password)‘;
UniQuery1.Params.ParamByName(‘username‘).Value := ‘eboy‘;
UniQuery1.Params.ParamByName(‘password‘).Value := ‘1111‘;
UniQuery1.ExecSQL; //如果不使用事务，这条将插入进去
UniQuery1.Params.Clear;
UniQuery1.SQL.Text := ‘insert into user (username,password)values(:username, :password)‘;
UniQuery1.Params.ParamByName(‘username‘).Value := ‘frr‘;
UniQuery1.Params.ParamByName(‘password‘).Value := ‘123‘;
UniQuery1.ExecSQL; //如果不使用事务，这条将插入进去
UniQuery1.Params.Clear;
UniQuery1.SQL.Text := ‘insert into user (username,password)values(:username, :password)‘;
UniQuery1.Params.ParamByName(‘username‘).Value := ‘lj‘;
UniQuery1.Params.ParamByName(‘password‘).Value := ‘880414‘;
UniQuery1.ExecSQL; //如果不使用事务，这条将插入进去
UniQuery1.Params.Clear;
UniQuery1.SQL.Text := ‘insert into user (username,password)values(:username, :password)‘;
UniQuery1.Params.ParamByName(‘username‘).Value := ‘lj‘;
UniQuery1.Params.ParamByName(‘password‘).IsNull; //字段设为not null，所以这里会出错
UniQuery1.ExecSQL; //开启事务后，上面的三条都将回滚
UniTransaction1.Connections[0].Commit;
except on e: Exception do
begin
UniTransaction1.Connections[0].Rollback;
ShowMessage(e.Message);
end;
end;
finally
UniConnection1.Disconnect;
end;
end;