To achieve what you want you need to provide some aditional configuration.Code First convention can identify bidirectional relationships, but not when there are multiple bidirectional relationships between two entities.You can add configuration (using Data Annotations or the Fluent API) to present this information to the model builder. With Data Annotations, you’ll use an annotation called … Read more
Two-step process Create the table without a foreign key CREATE TABLE PLANETICKETS( DESTINATION VARCHAR(10) NOT NULL, TICKETPRICE NUMERIC(8,2) NOT NULL, TOURISTINFO_ID INT ) Add the foreign key constraint ALTER TABLE PLANETICKETS ADD FOREIGN KEY (TOURISTINFO_ID) REFERENCES TOURISTINFO(TOURISTINFO_ID) One-step process CREATE TABLE PLANETICKETS( DESTINATION VARCHAR(10) NOT NULL, TICKETPRICE NUMERIC(8,2) NOT NULL, TOURISTINFO_ID INT, foreign key (TOURISTINFO_ID) … Read more
Don’t use the User model directly. From the documentation Instead of referring to User directly, you should reference the user model using django.contrib.auth.get_user_model() When you define a foreign key or many-to-many relations to the user model, you should specify the custom model using the AUTH_USER_MODEL setting. Example: from django.conf import settings from django.db import models … Read more
You can use this script: IF EXISTS (SELECT * FROM sys.foreign_keys WHERE object_id = OBJECT_ID(N'[dbo].[FK_NAME]’) AND parent_object_id = OBJECT_ID(N'[dbo].[MyTable]’)) BEGIN — do stuff END This can be done if you expand out the table and right click on an existing FK and choose script key as “DROP TO” and then you will get a generated … Read more
Never mind, this is the correct answer: http://msdn.microsoft.com/en-us/library/aa175805(SQL.80).aspx SELECT KCU1.CONSTRAINT_SCHEMA AS FK_CONSTRAINT_SCHEMA ,KCU1.CONSTRAINT_NAME AS FK_CONSTRAINT_NAME ,KCU1.TABLE_SCHEMA AS FK_TABLE_SCHEMA ,KCU1.TABLE_NAME AS FK_TABLE_NAME ,KCU1.COLUMN_NAME AS FK_COLUMN_NAME ,KCU1.ORDINAL_POSITION AS FK_ORDINAL_POSITION ,KCU2.CONSTRAINT_SCHEMA AS REFERENCED_CONSTRAINT_SCHEMA ,KCU2.CONSTRAINT_NAME AS REFERENCED_CONSTRAINT_NAME ,KCU2.TABLE_SCHEMA AS REFERENCED_TABLE_SCHEMA ,KCU2.TABLE_NAME AS REFERENCED_TABLE_NAME ,KCU2.COLUMN_NAME AS REFERENCED_COLUMN_NAME ,KCU2.ORDINAL_POSITION AS REFERENCED_ORDINAL_POSITION FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS AS RC INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS KCU1 ON … Read more
You shouldn’t really do this but insert in a new record instead and update it that way. But, if you really need to, you can do the following: Disable enforcing FK constraints temporarily (e.g. ALTER TABLE foo WITH NOCHECK CONSTRAINT ALL) Then update your PK Then update your FKs to match the PK change Finally … Read more
Yes, you can do that. You just need to make it clear for hibernate which one is the mapping that it’s supposed to maintain, like so: @Column(name=”message_key”, updatable=false, insertable=false) private Long message_fk;
You should make car_id a primary key in cars.
Sure, no problem: CREATE TABLE dbo.[User] ( Id int NOT NULL IDENTITY PRIMARY KEY, Name nvarchar(1024) NOT NULL ); CREATE TABLE [Group] ( Id int NOT NULL IDENTITY PRIMARY KEY, Name nvarchar(1024) NOT NULL ); CREATE TABLE [UserToGroup] ( UserId int NOT NULL, GroupId int NOT NULL, PRIMARY KEY CLUSTERED ( UserId, GroupId ), FOREIGN … Read more
AFAIK, dropping the constraint, then rename, then add the constraint back is the only way. Backup first!