我们如何修改MySQL视图的定义而不删除它？
借助ALTERVIEW语句，我们可以修改MySQL视图的定义。在这种情况下，我们不需要删除它。语法如下-
语法
ALTER VIEW view_name AS SELECT column1,column2… FROM table WHERE conditions;
示例
为了说明这一点，我们正在修改名为“Info”的视图的定义，该视图具有以下数据-
mysql> Select * from Info; +------+---------+------------+ | Id | Name | Subject | +------+---------+------------+ | 101 | YashPal | History | | 105 | Gaurav | Literature | | 125 | Raman | Computers | | 130 | Ram | Computers | +------+---------+------------+ 4 rows in set (0.01 sec)
现在，假设如果我们要在此视图中再添加一列，则可以借助ALTERVIEW语句来完成，如下所示：
mysql> Alter view info AS SELECT ID, NAME, SUBJECT, ADDRESS from student_info; mysql> Select * from info; +------+---------+------------+------------+ | ID | NAME | SUBJECT | ADDRESS | +------+---------+------------+------------+ | 101 | YashPal | History | Amritsar | | 105 | Gaurav | Literature | Chandigarh | | 125 | Raman | Computers | Shimla | | 130 | Ram | Computers | Jhansi | +------+---------+------------+------------+ 4 rows in set (0.00 sec)
上面的结果集显示已将ADDRESS列添加到视图“Info”中。