Question

我使用'MariaDB 5.5 x64' and Client HeidiSQL 服务器环境是Windows Server2012 Datacenter 并且数据库use_progress正在跟随

行

int id //自动增量主键
  int owner //所有者用户的唯一ID
  varchar [20] name // key
  int值//值

它存储在线游戏用户的状态键值类型

例如

id  owner name           value
856 656   stage0cleared  0
857 656   have_gold      10214  
858 657   inventory      22

并且下一个查询的工作测试很好

select count(*) from use_progress where owner = 656 and name = "inventory";

INSERT INTO use_progress (use_progress.owner, use_progress.name, use_progress.value) VALUES (656, 'inventory', 7);

UPDATE use_progress SET use_progress.value = 7 WHERE use_progress.`owner` = 656 AND use_progress.`name` = 'inventory';

但下一个查询是错误1064（语法错误）

BEGIN  
    IF ((select count(*) from use_progress where owner = 656 and name = "inventory") = 0 )   THEN  
        INSERT INTO use_progress (use_progress.owner, use_progress.name, use_progress.value) VALUES (656, 'inventory', 7);  
    ELSE  
        UPDATE use_progress SET use_progress.value = 7 WHERE use_progress.`owner` = 656 AND use_progress.`name` = 'inventory';  
    END IF;  
END

错误正在接下来（总是那个错误）：

/* SQL error (1064): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'IF ((select count(*) from use_progress where owner = 656 and name = "inventory")' at line 2 */

我尽我所能。是否使用（）或不使用 dbname.tablename。前缀到每个列名称。但在任何情况下，都会发生同样的错误。

我甚至试过这个（第2行改变了）：

BEGIN  
    IF (1>2)   THEN  
        INSERT INTO use_progress (use_progress.owner, use_progress.name, use_progress.value) VALUES (656, 'inventory', 7);  
    ELSE  
        UPDATE use_progress SET use_progress.value = 7 WHERE use_progress.`owner` = 656 AND use_progress.`name` = 'inventory';  
    END IF;  
END

但同样的错误发生（消息相同）
我不知道为什么会这样。

Answer 1

您不能在简单查询中使用IF() THEN ...等控制结构，只能在存储过程或函数中使用。

在这种情况下，您使用存储过程。试试这样：

DELIMITER $$
CREATE PROCEDURE my_proc_name(IN p_owner int, IN p_name varchar(50), IN p_value int)
BEGIN  
    IF NOT EXISTS (select 1 from use_progress where owner = p_owner and name = p_name) THEN  
        INSERT INTO use_progress (owner, name, `value`) VALUES (p_owner, p_name, p_value);  
    ELSE  
        UPDATE use_progress SET `value` = p_value WHERE `owner` = p_owner AND `name` = p_name;  
    END IF;  
END $$
DELIMITER ;

创建后，您可以这样称呼它：

CALL my_proc_name(656, 'inventory', 7);

查询始终返回1064语法错误

1 个答案: