从table1中选择table1中条件特定元素不存在于table2中

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

我希望获取5000个随机行，条件是solved

表user = username中找不到任何行

到目前为止，我已尝试过：

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

将LEFT JOIN用于thar：

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