sqlite外键约束中。restrict约束:如果要删除父表,则子表需空。 如果没有定义约束。会报错,需设置一个约束。
Remove foreign key b and unique_together constraint from model like following: class A(models.Model): name = models.CharField(max_length=10) b = models.ForeignKey('B') class Meta: unique_together = (('b','name'),) class B(models.Model): text = models.CharField(max_length=10) --...
Discover how to use SQL ALTER TABLE DROP CONSTRAINT to remove data integrity constraints. Learn syntax and examples for dropping PRIMARY KEY, UNIQUE, and other constraints.
constraint_name="_conda_package_build_uc", ) # add channel column batch_op.add_column( Column("channel_id", INTEGER) ) batch_op.create_foreign_key("fk_channel_id", "conda_channel", ["channel_id"], ["id"]) # re-add the constraint with the channel column batch_op.create_unique_co...
Can't add datetime column with default value in SQL Server 2005 Can't change the currente collate of my database Can't copy the result of a query? Can't declare table parameter as input to stored procedure Can't delete rows from Mgt Studio view Can't Enable Foreign Key Constraint (M...
Foreign key constraint error with delete Free up SQL Server Memory Frequently getting Provider ran out of memory error Full database backup can full transection log Files? Full Text Search Populate Status - Processing notifications FullText creation fails with Error: 30059, Severity: 16, State: 1...
(0) NULL DEFAULT NULL COMMENT '创建时间', PRIMARY KEY (`id`) USING BTREE, INDEX `manager_fk`(`manager_id`) USING BTREE, CONSTRAINT `manager_fk` FOREIGN KEY (`manager_id`) REFERENCES `user` (`id`) ON DELETE RESTRICT ON UPDATE RESTRICT ) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE...
SQL Data Types SQL View SQL CREATE VIEW SQL Index SQL CREATE INDEX SQL DROP TABLE SQL TRUNCATE TABLE SQL USE SQL CREATE DATABASE SQL DROP DATABASE SQL GRANT SQL REVOKE SQL CONSTRAINT NOT NULL Constraint DEFAULT Constraint UNIQUE Constraint CHECK Constraint PRIMARY KEY FOREIGN KEY SQL ALTER TABLE...
Explore All features Documentation GitHub Skills Blog Solutions By company size Enterprises Small and medium teams Startups Nonprofits By use case DevSecOps DevOps CI/CD View all use cases By industry Healthcare Financial services Manufacturing Government View all industries View all sol...
Cannot add foreign key constraint 2019-08-23 11:03 −产生这个错误的多数原因有(4、5主要): 1,两张表里要设主键和外键的字段的数据类型或者数据长度不一样 (例如这个是int 另外一个是varchar,或者都是int,但是设置的长度不同) 2,某个表里已经有记录了 3、两个表的引擎不一样,查看表的引擎语句: show...