如果在 FOREIGN KEY 约束的 ON UPDATE 和/或 ON DELETE 子句上指定 NO ACTION 选项,则 SQL Server 将返回UPDATE_RULE和/或DELETE_RULE列的SQL_NO_ACTION。当任何 SQLForeignKeys 参数中存在无效值时, SQLForeignKeys 在执行时返回SQL_SUCCESS。 在这些参数中使用无效值时,SQLFetch 将返回SQL_NO_DATA。
使用关键字foreign key 语法:alter table 表名 add constraint FK_ID foreign key(你的外键字段名) references外表表名(对应的表的主键字段名); 例: alter table tb_active add constraint FK_ID foreign key(user_id)referencestb_user(id) (4)下面用实例演绎上面的itcast_student 和itcast_class: ->1.首先...
mysql>create table book2author(->id int primary key auto_increment,->book_id int,-> foreign key(book_id) references book(id) on update cascade on delete cascade,#设置外键->author_id int,-> foreign key(author_id) references author(id) on update cascade on delete cascade#设置外键->);#...
MySQL的语句中用来设定外键的参考动作的子句有两大类:on delete和on update。语法是 [CONSTRAINT [symbol]] FOREIGN KEY [index_name] (col_name, ...) REFERENCES tbl_name (col_name,...) [ON DELETE reference_option] [ON UPDATE reference_option] 1. 2. 3. 4. 5. 由字面可以看出,on delete就...
Status:Not a BugImpact on me: None Category:MySQL Server: InnoDB storage engineSeverity:S2 (Serious) Version:5.1.41OS:Windows (Win 7) Assigned to:CPU Architecture:Any Tags:foreign key on update cascade self-reference [27 Oct 2010 11:58] Luca Esculapio ...
constrant 外键名称 foreign key(外键字段) references 父表(主键字段); 1. 创建两种表 -- 创建班级表 create table class( id int primary key, course varchar(20) not null comment '课程', room varchar(20) not null comment '教室' )charset utf8; ...
命令格式：[CONSTRAINT [symbol]] FOREIGN KEY[index_name] (col_name, …)REFERENCES tbl_name (col_name,…)[ON DELETE reference_option][ON UPDATE reference_option]reference_option:RESTRICT | CASCADE | SET NULL | NO ACTION | SET DEFAULT 以上是完整的官方命令格式，看着都晕呀。[CONSTRAINT <外键名...
ERROR 1452 (23000): Cannot add or update a child row: a foreign key constraint fails (`test/child`, CONSTRAINT `child_ibfk_1` FOREIGN KEY (`parent_id`) REFERENCES `parent` (`id`) ON DELETE CASCADE) 因为4不在主表中,插入时发生了外键约束错误。
Bug #37794 Foreign key options ( onDelete, onUpdate ) not imported from DBDesigner schema Submitted: 2 Jul 2008 8:49Modified: 10 Jul 2008 14:02 Reporter: Antoine Noal Email Updates: Status: Closed Impact on me: None Category: MySQL WorkbenchSeverity: S2 (Serious) Version: 5.0.23OS:...
UPDATE 语句与 FOREIGN KEY 约束"FK_LateCkeck_Regions"冲突。该冲突发生于数据库"F:\ATTENDANCE6\WEB\APP_DATA\***.mdf",表"***.regions", column 'RegionId'。语句已终止。 ysl2731616922 采纳率:53% 等级:7 已帮助:10人 私信TA向TA提问