从表 1 中选择表 1 中的条件特定元素在表 2 中不存在

Question

表 words 包含列：word_id word

我的查询打印为：

SELECT word FROM words WHERE condition1 AND condition2 ORDER BY RAND() LIMIT 5000

表 solved 包含列：user_id word_id

我想获取 5000 个随机行，条件是在表 solved 中找不到任何一行 user = username

到目前为止我已经尝试过：

SELECT word FROM words w 
WHERE not exists 
(select 1 from solved s where s.word_id = w.word_id 
AND s.user_id = 'username') 
AND condition1 AND condition2 ORDER BY RAND() LIMIT 5000

Answer 1

使用LEFT JOIN 表示：

SELECT word 
FROM words w 
left join solved s on s.word_id = w.word_id AND s.user_id = 'username'
WHERE w.word_id is null
AND condition1 AND condition2 
ORDER BY RAND() LIMIT 5000