如何使用行数更新 mysql 查询

Question

我想对显示列重新排序，以便顺序没有间隙。像下面这样的可能吗

UPDATE foo
INNER JOIN bar ON foo.barid = bar.id 
SET foo.display = !rowcount!
WHERE bar.baz = 1
ORDER BY foo.display;

Answer 1

你想要这个吗？

UPDATE foo
INNER JOIN (
    SELECT t2.id, @rowNo := @rowNo + 1 AS rowcount
    FROM foo t1
    INNER JOIN bar t2 ON t1.barid = t2.id
    INNER JOIN (SELECT @rowNo := 0) t
    WHERE t2.baz = 1
    ORDER BY t1.display) bar ON foo.barid = bar.id 
SET foo.display = bar.rowcount

如何使用行数更新 mysql 查询

How can I update a mysql query with the row count

mysql

mariadb