Question

我的初始插入语句工作正常，但我想将自定义结果发送回我的应用程序。这可能吗？（参见下面的最后一条SELECT语句）：

-- this is working    
INSERT INTO users (email, firstName, lastName, password)

SELECT * FROM (
    SELECT '{{email}}' as email, 
    'test' as firstName, 
    'person' as lastName, 
    '{{password}}' as password) AS tmp
WHERE NOT EXISTS (
    SELECT email FROM users WHERE email = '{{email}}'
) LIMIT 1;

-- this statement is not working.
SELECT IF(ROW_COUNT() > 0, 
    SELECT * FROM users WHERE email = '{{email}}', 
    'failure'
);

运行它给了我：

错误详细信息：SQL语法中存在错误;查看与您的MySQL服务器版本相对应的手册，以便在＃＆...; SELECT * FROM users附近使用正确的语法WHERE email =＆＃39; d@gmail.com'，＆＃39; failure＆＃39; ）＆＃39;在第2行

Answer 1

我认为你要做的事情是：

SELECT IF(
    (SELECT COUNT(*) FROM users WHERE email = '{{email}}') > 0,
    'success',
    'false'
);

Answer 2

用这个替换最后一个查询：

SELECT * FROM users WHERE `id`= LAST_INSERT_ID()

如果插入成功，MySQL返回行，否则返回＆＃39;失败＆＃39;

2 个答案: