SET DEFAULTis also supported by the MySQL Server but is currently rejected as invalid byInnoDB. Since MySQL does not support deferred constraint checking,NO ACTIONis treated asRESTRICT. For the exact syntax supported by MySQL for foreign keys, seeSection 15.1.20.5, “FOREIGN KEY Constraints”. MA...
13.3 FOREIGN KEY Constraint Differences The MySQL implementation of foreign key constraints differs from the SQL standard in the following key respects: If there are several rows in the parent table with the same referenced key value, InnoDB performs a foreign key check as if the other parent ...
create table主表名称(字段1数据类型 primary key,字段2数据类型);create table从表名称(字段1数据类型 primary key,字段2数据类型,[CONSTRAINT<外键约束名称>]FOREIGNKEY(从表的某个字段)references主表名(被参考字段));//(从表的某个字段)的数据类型必须与主表名(被参考字段)的数据类型一致,逻辑意义也一样//(...
MySQL Error Number 1005 Can't create table '.\homebase\user-link-cat.frm' (errno: 150) It would seem that I have a malformed set of foreign key constraints, but I can't figure how. Does anyone see my problem? Is there a way to get a more informative error message? Any assistanc...
http://dev.mysql.com/doc/refman/5.5/en/innodb-foreign-key-constraints.html 中文网站 http://dev.mysql.com/doc/refman/5.1/zh/sql-syntax.html 【5】 对外键讲解的比较全面,可以一读 http://www.xiaoxiaozi.com/2009/07/12/1158/ http://feidaodalian.iteye.com/blog/550179...
http://dev.mysql.com/doc/refman/5.5/en/innodb-foreign-key-constraints.html 中文网站 http://dev.mysql.com/doc/refman/5.1/zh/sql-syntax.html 【5】 对外键讲解的比较全面,可以一读 http://www.xiaoxiaozi.com/2009/07/12/1158/ ...
mysql创建表 Foreign key Mysql创建表30天过期 Mysql数据表操作 创建一个原本没有的数据表: create table if not exits语句,无需假设它需要用到的数据表是否存在。当存在一个相同的表名时用create table语句创建时就会出错。所以使用 If not exits语句就不会有这些问题了。
在MySQL中,错误代码1217表示“cannot delete or update a parent row: a foreign key constraint”,即无法删除或更新父表(主键表)中的记录,因为存在外键约束。下面我将详细解释这个问题,并提供解决方法。 1. 解释什么是外键约束以及它如何工作 外键约束是数据库中的一种约束,用于维护数据之间的引用完整性。它确保一...
Mysql FOREIGN KEY Constraints InnoDB支持 foreign key constraints. constraint definition inInnoDBlooks like this: [CONSTRAINT [symbol]] FOREIGN KEY [index_name] (index_col_name, ...) REFERENCEStbl_name(index_col_name,...) [ON DELETEreference_option]...
Foriengn key constraints are not working on MYSQL Innodb in Linux Fedora environment. I need help in this regard! Example script are: CREATE TABLE fiscal_year ( id INTEGER UNSIGNED NOT NULL, name VARCHAR(30) NOT NULL, start_date DATE NOT NULL, ...