sql - MySQL，删除带有连接的查询

Question

谁能帮我理解这个查询有什么问题:

DELETE FROM noteproject 
INNER JOIN note ON noteproject.noteID = note.noteID
INNER JOIN person ON note.personID = person.personID
WHERE noteID = '#attributes.noteID#' 
  AND personID = '#attributes.personID#'

Answer 1

目前我没有数据库来测试我在说什么，但是here's a reference to the mysql docs以您的案例为例:

You can specify multiple tables in a DELETE statement to delete rows from one or more tables depending on the particular condition in the WHERE clause.

还有:

1) For the first multiple-table syntax, only matching rows from the tables listed before the FROM clause are deleted.
2)For the second multiple-table syntax, only matching rows from the tables listed in the FROM clause (before the USING clause) are deleted.
The effect is that you can delete rows from many tables at the same time and have additional tables that are used only for searching:

1)
DELETE t1, t2 
FROM t1 INNER JOIN t2 INNER JOIN t3
WHERE t1.id=t2.id AND t2.id=t3.id;

2)
DELETE FROM t1, t2 
USING t1 INNER JOIN t2 INNER JOIN t3
WHERE t1.id=t2.id AND t2.id=t3.id;

These statements use all three tables when searching for rows to delete, but delete matching rows only from tables t1 and t2.