mysql - 选择和删除

Question

我需要从表中删除某些行。必须删除哪些行是我通过查询发现的。然而，it appears that you cannot do both operations (select and delete) in the same query :

Currently, you cannot delete from a table and select from the same table in a subquery.

所以我不能这样做:

DELETE
FROM telefono
WHERE telefono_id IN (
    SELECT te.telefono_id
    FROM telefono te
    LEFT JOIN centro_telefono ce ON te.telefono_id=ce.telefono_id AND ce.telefono_id IS NOT NULL
    LEFT JOIN contacto_telefono co ON te.telefono_id=co.telefono_id AND co.telefono_id IS NOT NULL
    WHERE COALESCE(ce.telefono_id, co.telefono_id) IS NULL AND te.fecha_alta < DATE_SUB(NOW(), INTERVAL 1 DAY)
);
-- SQL Error (1093): You can't specify target table for update in FROM clause

如何在纯 MySQL 中实现此记录清理？

服务器运行 MySQL 5.1.39。

Answer 1

尝试使用连接执行删除语句

DELETE te
FROM telefono as te
    LEFT JOIN centro_telefono ce
        ON te.telefono_id=ce.telefono_id AND ce.telefono_id IS NOT NULL
    LEFT JOIN contacto_telefono co
        ON te.telefono_id=co.telefono_id AND co.telefono_id IS NOT NULL
WHERE
    COALESCE(ce.telefono_id, co.telefono_id) IS NULL
    AND te.fecha_alta < DATE_SUB(NOW(), INTERVAL 1 DAY)