我想從引用指定表的表中刪除外鍵。我不知道外鍵的名字,我只知道它所在的表格和它引用的表格。這是我走到這一步:如何動態地從MySQL表中刪除外鍵?
alter table tblTableWhereFKIs drop foreign key (select constraint_name
from information_schema.key_column_usage
where referenced_table_name = 'tblReferencedByFK' and table_name = 'tblTableWhereFKIs' limit 1);
但我得到一個錯誤:
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '(select constraint_name
from information_schema.key_column_usage
where referen' at line 1
的選擇單獨的作品:
mysql> select constraint_name
-> from information_schema.key_column_usage
-> where referenced_table_name = 'tblReferencedByFK' and table_name = 'tblTableWhereFKIs' limit 1;
+-----------------------------------------+
| constraint_name |
+-----------------------------------------+
| fk_tblTableWhereFKIs_tblReferencedByFK1 |
+-----------------------------------------+
1 row in set (0.08 sec)