mysql - 在 View 中动态获取表中的所有列

Question

在 MySQL 中，保存以下 View 后:

CREATE VIEW MyView AS SELECT * FROM MyTable;

如果我编辑MyView，星号就会消失，并且 SQL 包含所有字段名称。例如:

ALTER VIEW MyView AS SELECT field1, field2 FROM MyTable;

当MyTable添加了新字段时，我希望 View 输出也显示这些新字段。如何防止星号被文字列名称替换？

Answer 1

View 是虚拟表的存储查询。因此更改原始表不会影响虚拟表 因此要更新 View ，您需要删除它然后重新创建它

DROP VIEW MyView 

然后

CREATE VIEW MyView AS SELECT * FROM MyTable;

The view definition is “frozen” at creation time, so changes to the underlying tables afterward do not affect the view definition. For example, if a view is defined as SELECT * on a table, new columns added to the table later do not become part of the view. the source