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) --...
Here are the general steps to remove a foreign key entry: Identify the table and column that contains the foreign key constraint. Disable the foreign key constraint to allow the deletion of the related records. This can usually be done using database management tools or SQL commands specific to...
CONSTRAINT emlyee_dept_fk FOREIGN KEY(deptId) REFERENCES dept(id) 约束 外键名称 外键 参照 参考表(参考字段) 外键 多表的设计 一对多:(非常多) CREATE TABLE department( id int primary key, name varchar(100), floor int ); CREATE TABLE employee( id int primary key, name varchar(100), salary ...
That’s only possible if you remove all elements of the ElementCollection first. Otherwise, it will fail for a foreign key constraint violation. If you tell Hibernate to remove one specific entity, it handles that automatically. But by using a JPQL DELETE statement, you are responsible for han...
..., (integrity-constraintk)) r is the name of the relation each Ai is an attribute name in the schema of relation r Di is the data type of values in the domain of attribute Ai Example: create tableinstructor ( ID char(5),
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...
CONSTRAINT "AgentGraph_agentGraphParentId_version_fkey" FOREIGN KEY ("agentGraphParentId", "version") REFERENCES "AgentGraph" ("id", "version") ON DELETE RESTRICT ON UPDATE CASCADE ); INSERT INTO "new_AgentGraph" ("agentGraphParentId", "description", "id", "isActive", "isTemplate", "...
2016-02-02 16:20:58,927 http-bio-18095-exec-4 WARN [engine.jdbc.spi.SqlExceptionHelper] SQL Error: 0, SQLState: 23503 2016-02-02 16:20:58,927 http-bio-18095-exec-4 ERROR [engine.jdbc.spi.SqlExceptionHelper] ERROR: update or delete on table"cwd_user"violates foreign key constraint"...