create table Table1 ( id varchar(2), name varchar(2), PRIMARY KEY (id) ) Create table Table1_Addr ( addid varchar(2), Address varchar(2), PRIMARY KEY (addid) ) Create table Table1_sal ( salid varchar(2),`enter code here` addid varchar(2), id varchar(2), PRIMARY KEY (salid), index(addid), index(id), FOREIGN KEY (addid) REFERENCES Table1_Addr(addid), FOREIGN KEY (id) REFERENCES Table1(id) )
alter table tab1 add c1 number(20) constraint tab1_c1_fk references tab2(c2); c1 new column in the table tab1 with the FK tab1_c1_fk on the table tab2 column c2.
EXEC sp_MSforeachtable @command1=”ALTER TABLE ? NOCHECK CONSTRAINT ALL” GO You may also want to do this: EXEC sp_MSforeachtable @command1=”ALTER TABLE ? DISABLE TRIGGER ALL” GO To enable them afterwards EXEC sp_MSforeachtable @command1=”ALTER TABLE ? ENABLE TRIGGER ALL” GO — SQL enable all constraints – enable all constraints sql server — sp_MSforeachtable is an undocumented system … Read more
In the tab where you define the table structure, you get the list of columns and their properties and underneath that there should be a link “relation view“, between “print view”, and “propose table structure.” That’s where you want to go, but you have to have created the index on both tables already. Also, you … Read more
You can either disable it for your entire context by removing the cascade delete convention in the OnModelCreating method: protected override void OnModelCreating( DbModelBuilder modelBuilder ) { modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>(); } or, you can do it per relationship using a fluent mapping (also in the OnModelCreating): EDIT: you would put it in your menu entities public class … Read more
Are you sure foreign key support is enabled? Assuming the library is compiled with foreign key constraints enabled, it must still be enabled by the application at runtime, using the PRAGMA foreign_keys command. For example: sqlite> PRAGMA foreign_keys = ON;
Differences between OneToOneField(SomeModel) and ForeignKey(SomeModel, unique=True) as stated in The Definitive Guide to Django: OneToOneField A one-to-one relationship. Conceptually, this is similar to a ForeignKey with unique=True, but the “reverse” side of the relation will directly return a single object. In contrast to the OneToOneField “reverse” relation, a ForeignKey “reverse” relation returns a QuerySet. Example … Read more
I’ve been having the same problem. I just noticed the following note at the very bottom of the Laravel Schema docs: Note: The field referenced in the foreign key is very likely an auto increment and therefore automatically an unsigned integer. Please make sure to create the foreign key field with unsigned() as both fields … Read more
Just found this website that says that ‘409 Conflict’ should be used when ‘the request could not be completed due to a conflict with the current state of the resource’ and ‘where it is expected that the user might be able to resolve the conflict and resubmit the request’, then it gives an example when … Read more
has_one :requester, :class_name => “User”, :foreign_key => “requester_id” This line (from the code that you posted) indicates that the requester is a User, and the table users should contain a column requester_id that is the foreign key toward friend_requests records. The rails error message states that the column requester_id does not exists (you have to … Read more