嵌套查询与删除SQL语句

Question

我不知道怎么做，我需要解决它：

我有一个select语句：

SELECT 
     sum_lines.id, 
     sum_lines.line_id, 
     sum_lines.summary_id, 
     sum_lines.text_content, 
     sum_tbl.user_id 
FROM 
     sum_lines 
JOIN 
     sum_tbl 
ON 
     sum_lines.summary_id = sum_tbl.id 
WHERE 
     sum_tbl.user_id = 1 

我怎么能删除，这种说法与显示一切删除语句？

Answer 1

如果你想从两个表中删除，你需要两个删除：

delete sum_lines 
from sum_lines 
join sum_tbl on sum_lines.summary_id = sum_tbl.id where sum_tbl.user_id = 1 

delete from sum_tbl 
where sum_tbl.user_id = 1 

只要确保做一个备份，你删除的东西了。它可以很容易地做事情是这样的：

select * 
into sum_lines_backup 
from sum_lines 

select * 
into sum_tbl_backup 
from sum_tbl 

Answer 2

试试这个：

delete sum_lines from sum_lines as a 

join sum_tbl as b on b.id = a.id 

where b.user_id = 1 

确保列name sum_lines[id]数据必须与sum_tbl[id]匹配，否则它不会工作。也许sum_lines.summary_id = sum_tbl.id与数据库中的数据不匹配。