Mysql case语句不起作用

Question

我的数据库版本是5.6.34

我正在使用像这样的案例语句

SELECT 
    customerName, state, country
FROM
    customers
ORDER BY (CASE
    WHEN state IS NULL THEN country
    ELSE state
END);

表名是customers

我在 SQL 下的 mysql 数据库中编写这个查询，我还附上了我的表，你可以在那里看到，

问题是

#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 'state IS NULL THEN country     ELSE state END) LIMIT 0, 25' at line 6

如果有人帮助我，我将非常感激

Answer 1

只需删除那个 ()

SELECT 
    customerName, state, country
FROM
    customers
ORDER BY CASE
    WHEN state IS NULL THEN country
    ELSE state
END