mysqli查询具有多个条件的多个案例

如果条件首先为真，则需要选择数据，然后检查用户id是否存在；如果条件不为真，则需要选择条件二，然后检查用户id是否存在

使用的技术：Codigniter-Mysqli

SELECT *
FROM `tablename`
WHERE `user_id` = '1'
OR `user_id` IN('62', '63', '58', '6', '50', '19', '2', '17', '7', '3')
AND `user_id` NOT IN('35')
OR (CASE WHEN except_friends = 1 THEN FIND_IN_SET('1', friends_list), FALSE END CASE WHEN selected_friends = 1 THEN NOT FIND_IN_SET('1', friends_list), FALSE END) ORDER BY `id` desc

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Mysql语法错误

我认为您的查询中存在语法错误。试试这个

SELECT * FROM tablename
 WHERE user_id = '1' 
    OR user_id IN('62', '63', '58', '6', '50', '19', '2', '17', '7', '3') 
    AND user_id NOT IN('35') 
    OR 
    (CASE 
        WHEN except_friends = 1 
            THEN NOT FIND_IN_SET('1', friends_list)
        WHEN selected_friends = 1 
            THEN NOT FIND_IN_SET('1', friends_list)
    END) ORDER BY id desc

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在替换逗号之前，应该有一个else