can't add foreign key in mysql? 1createtabledepartment2(dept_namevarchar(20),3buildingvarchar(15),4budget numeric(12,2)check(budget>0),5primarykey(dept_name)6);78createtablecourse9(course_idvarchar(8),10titlevarchar(50),11dept_namevarchar(20),12credits numeric(2,0)check(credits>0),13p...
1、名(name):可以不填,保存时会自动生成。 2、栏位(FieldName):要设置的外键 3、参考数据库(Reference DataBase):外键关联的数据库 4、被参考表(Reference Table):关联的表 5、参考栏位(Forgin filed Names):关联的字段 6、删除时(ondelete):删除时候的动作 7、更新时(onupdate):更新时候的动作 以上字段...
Mysql foreign key 不能添加常见原因: 1.检查目标指向的字段是否是主键。 2.检查是否表内已经存有数据,导致约束失败 5.检查是否重建了同名的索引,比如第一次建立失败,再次建立可能会因为索引重复导致失败 6.可以设置一下 ON DELETE SET NULL ON UPDATE RESTR...
I am creating two tables then doing an alter table to add a foreign key constraint and it gives the following error: Error Code: 1005. Can't create table 'mydb.#sql-870_16' (errno: 150) Here is a simple test to prove it:
今天给mysql数据库中的表添加外键,保存时出现错误:[Err] 1215 - Cannot add foreign key constraint,导致无法添加外键。 外键定义添加的条件: (1)外键对应的字段数据类型保持一致 (2)所有tables必须是InnoDB型,它们不能是临时表.因为在MySQL中只有InnoDB类型的表才支持外键(两张表的存储引擎一致)。
mysql中，两个表要建外键必须都是InnoDB表，MyISAM表暂时不支持外键，估计就是引擎的问题 create
不能添加外键，检查下你的语法是否正确，外键约束是否正确
Bug #79918 Cannot add foreign key constraint Submitted: 11 Jan 2016 16:52Modified: 18 Apr 2019 16:25 Reporter: Stefano Giacone Email Updates: Status: Duplicate Impact on me: None Category: MySQL Server: InnoDB storage engineSeverity: S1 (Critical) Version: 5.7.10OS: Any (Win7 and ...
Reporter:MySQL DBAEmail Updates: Status:No FeedbackImpact on me: None Category:MySQL ServerSeverity:S2 (Serious) Version:5.1.30-ndb-6.3.20-cluster-gplOS:Linux (Fedora 8) Assigned to:CPU Architecture:Any Tags:Mysql foreign key constraint ...
I am new to learning SQL and I have a project that just doesnt make sense to me. Now when I type in the following code down below down, I get hit with the message "Cannot add foreign key constraint". The whole idea of adding foreign keys into SQL code is super confusing. HELP!!!