sql 事务使用

BEGIN TRAN Tran_Money    --开始事务

DECLARE @tran_error int;
SET @tran_error = 0;
    BEGIN TRY 
        UPDATE tb_Money SET MyMoney = MyMoney - 30 WHERE Name = '刘备';
        SET @tran_error = @tran_error + @@ERROR;
        --测试出错代码，看看刘备的钱减少，关羽的钱是否会增加
        --SET @tran_error = 1;
        UPDATE tb_Money SET MyMoney = MyMoney + 30 WHERE Name = '关羽';
        SET @tran_error = @tran_error + @@ERROR;
    END TRY

BEGIN CATCH
    PRINT '出现异常，错误编号：' + convert(varchar,error_number()) + ',错误消息：' + error_message()
    SET @tran_error = @tran_error + 1
END CATCH

IF(@tran_error > 0)
    BEGIN
        --执行出错，回滚事务
        ROLLBACK TRAN;
        PRINT '转账失败，取消交易!';
    END
ELSE
    BEGIN
        --没有异常，提交事务
        COMMIT TRAN;
        PRINT '转账成功!';
    END