mysql - SQL.查看命令错误

Question

我创建了两个表并使用 View 合并它们。我无法更新 View 表。更新命令不起作用。它会出现错误“数据操作操作在此 View 上不合法”。

SQL>UPDATE library 
SET bookno=176 WHERE rackno=33;

这里的library是 View 名称。谁能给我答案吗？

Answer 1

来自手册:https://dev.mysql.com/doc/refman/5.7/en/view-updatability.html

For a view to be updatable, there must be a one-to-one relationship between the rows in the view and the rows in the underlying table. There are also certain other constructs that make a view nonupdatable. To be more specific, a view is not updatable if it contains any of the following:

Aggregate functions (SUM(), MIN(), MAX(), COUNT(), and so forth)

DISTINCT

GROUP BY

HAVING

UNION or UNION ALL