我有两张桌子,首先,我需要做一些搜索来获得这样的另一张桌子的fk ......
SELECT `related_table_id`
FROM `table_a`
WHERE `users_id` = '14'
AND `user_data_status` = 'n'
AND `another_table_name` = 'table_b'
然后,我有很多related_table_id作为输出......我需要搜索内容,就像%keyword%。 所以,我需要查询另一个这样的SQL:
SELECT *
FROM table_b
WHERE (`table_b_id`='218' OR `table_b_id`='219' OR `table_b_id`='225')
AND `content` LIKE '%keyword%'
问题是,当我的数据库增长时,table_b可能有很多可以从table_a查询的数据,因此,sql语句将变得非常长。我可以将这两个陈述合二为一吗?谢谢你/
答案 0 :(得分:4)
您可以使用INNER JOIN
来“匹配”两个或多个表格的行。
SELECT table_b.*
FROM table_b
INNER JOIN table_a
ON table_a.related_table_id = table_b.table_b_id
WHERE table_a.users_id = '14'
AND table_a.user_data_status = 'n'
AND table_a.another_table_name = 'table_b'
AND table_b.content LIKE '%keyword%'
答案 1 :(得分:3)
执行嵌套查询:
SELECT * FROM table_b WHERE `table_b_id` IN (SELECT `related_table_id` FROM `table_a` WHERE `users_id` = '14' AND `user_data_status` = 'n' AND `another_table_name` = 'table_b') AND `content` LIKE '%keyword%'