postgres=> create table t3 ( a int primary key, b text, c date); CREATE TABLE postgres=> create table t4 ( a int primary key, b int references t3(a), c text); CREATE TABLE postgres=> alter table t4 disable trigger all; ERROR: permission denied: "RI_ConstraintTrigger_c_75235" is...
mysql> insert into t_tudent values(112,'爱国的吴京',6); ERROR 1452 (23000): Cannot add or update a child row: a foreign key constraint fails (`test_wl`.`t_tudent`, CONSTRAINT `t_tudent_ibfk_1` FOREIGN KEY (`t_class`) REFERENCES `t_class` (`class_num`)) 1. 2. 3. 4. 5...
ALTER TABLE table_name DROP CONSTRAINT foreign_key_name; 完成操作后,重新创建外键约束: sql ALTER TABLE table_name ADD CONSTRAINT foreign_key_name FOREIGN KEY (column_name) REFERENCES other_table(other_column); 方法四:使用事务和异常处理 在事务中执行操作,并在遇到外键约束错误时回滚事务。这种方法...
In this post, I am sharing one option to Disable / Enable the Foreign Key Constraint in PostgreSQL. During data migration and testing purpose, Database Developer requires to disable Foreign key constraint of a Table. Once you disable constraint, then later you might need t...
问迁移Postgresql时禁用对外键的所有检查EN这几天在 Mac 下装了微软的 Visual Studio Code（下面简称 ...
enable constraint CLIENT_TYPE_2019; //启用 alter table FM_CLIENT disable constraint CLIEN ...
A FOREIGN KEY constraint contain the value in a column or combination of columns which must be appearing in the same column or group of columns in another table.
ALTER TABLE 从表名 ADD CONSTRAINT 外键约束名 FOREIGN KEY (从表的外键) REFERENCES 主表名 (主表的主键); 1 注意:如果要给一个已存在的表添加 ON DELETE CASCADE 的外键约束,需要如下步骤: 删除已存在的外键约束。 添加一个 ON DELETE CASCADE 的外键约束。
alter table WS_YBJZQK disable constraint FK_WS_YBJZQ_REFERENCE_RY_JBXX; 1. 2. 3. 3. 启用所有外键约束: select 'alter table ' || table_name || ' enable constraint ' || constraint_name ||';' from user_constraints where constraint_type = 'R'; ...
在PostgreSQL 中,我们使用 FOREIGN KEY 关键字来定义外键。外键通常和 REFERENCES 关键字配合使用。具体的语法如下:CREATE TABLE 表名 ( 列名 数据类型, ... CONSTRAINT 约束名 FOREIGN KEY (列名) REFERENCES 引用表名 (引用列名) [ON DELETE 动作] [ON UPDATE 动作] ); SQL Copy...