mysql>DELETEFROMparentWHEREidVALUES=1;ERROR 1451 (23000):Cannot delete or update a parent row:a foreign key constraint fails (`test`.`child`, CONSTRAINT `child_ibfk_1` FOREIGN KEY (`parent_id`) REFERENCES `parent` (`id`)) This operation fails because the record in the child table contai...
3.外键关系的两个表的列必须是数据类型相似,也就是可以相互转换类型的列,比如int和tinyint可以,而int和char则不可以; 外键的好处:可以使得两张表关联,保证数据的一致性和实现一些级联操作; 外键的定义语法: [CONSTRAINT symbol] FOREIGN KEY [id] (index_col_name, ...) REFERENCES tbl_name (index_col_name...
ERROR1452 (23000): Cannot add or update a child row: a foreign key constraint fails (`test`.`subtb`, CONSTRAINT `subtb_ibfk_1` FOREIGN KEY (`rootid`) REFERENCES `roottb` (`id`) ON DELETE CASCADE) mysql> FOREIGN KEY reference UNIQUE KEY not primary CREATETABLEroottb3 ( idINT(11) ...
(1)I tried to run "alter table myTableA change myIdA myIdA int, foreign key (myIdA) references myTableB (myIdB)", it did not work. alter table myTableA add foreign key (myIdA) references myTableB(myIdB); Quote (2) Is it possible to embedded a bash script in a table feild ...
Foreign keys let you cross-reference related data across tables, andforeign key constraintshelp keep this spread-out data consistent. MySQL supportsON UPDATEandON DELETEforeign key references inCREATE TABLEandALTER TABLEstatements. The available referential actions areRESTRICT,CASCADE,SET NULL, andNO ACTI...
ALTERTABLEtbl_nameADD[CONSTRAINT[symbol]]FOREIGNKEY[index_name](index_col_name,...)REFERENCEStbl_name(index_col_name,...)[ONDELETEreference_option][ONUPDATEreference_option] 示例: mysql>createtableChild2(->idintprimarykey,->namevarchar(20),->pidint);Query OK,0rowsaffected(0.06sec)# 下面添加...
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...
On reference creation, Database Designer for MySQL performs the following actions: 1. Creates new column(s) in the referencing table, their parameters (name, data type) will be copied from the primary key constraint of the referenced table. If the referencing table already has column(s) analog...
Category:MySQL Cluster: Cluster (NDB) storage engineSeverity:S2 (Serious) Version:7.3.0OS:Windows (7, 64 bit) Assigned to:CPU Architecture:Any Tags:foreign key,reference table name case View Add Comment Files Developer Edit Submission View Progress Log ...
ADDR_PK_ID is foreign key to addressdetails PK_ID similiarly PHN_PK_ID is foreign key to phonedetails PK_ID What im trying to do is write a query that will return distinct ADDR_PK_ID values for certain values of PHN_PK_ID. This works fine if I want OR results on the PHN_PK...