foreign-keys

I have a SQLServer with a linked server onto another database somewhere else. I have created a view on that linked server create view vw_foo as select [id], [name] from LINKEDSERVER.RemoteDatabase.dbo.tbl_bar I'd like to to the following alter table [baz] add foo_id int not null go alter table [baz] with check add constraint [fk1_baz_to_foo] foreign key([foo_id]) references [dbo].[vw_foo] ([id]) go But that generates the error: "Foreign key 'fk1_baz_to_foo' references object 'dbo.vw_foo' which is not a user table." If I try and put the foreign key directly onto the table using the following

My question is related to this one I asked on ServerFault . Based on this, I've considered the use of BULK INSERT . I now understand that I have to prepare myself a file for each entities I want to save into the database. No matter what, I still wonder whether this BULK INSERT will avoid the memory issue on my system as described in the referenced question on ServerFault. As for the Streets table, it's quite simple! I have only two cities and five sectors to care about as the foreign keys. But then, how about the Addresses? The Addresses table is structured like this: AddressId int not null

How to enforce a constraint of foreign key on columns of same table in SQL while entering values in the following table: employee : empid number, manager number (must be an existing employee) instanceOfObject CREATE TABLE TABLE_NAME ( `empid_number` int ( 11) NOT NULL auto_increment, `employee` varchar ( 100) NOT NULL , `manager_number` int ( 11) NOT NULL , PRIMARY KEY (`empid_number`), CONSTRAINT `manager_references_employee` FOREIGN KEY (`manager_number`) REFERENCES (`empid_number`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 Hope it helps! Oracle call this a self-referential integrity constraint.

I am working with a few legacy tables that have relationships, but those relationships haven't been explicitly set as primary/foreign keys. I created a .dbml file using "Linq To Sql Classes" and established the proper Case.CaseID = CaseInfo.CaseID association. My resulting class is CasesDataContext. My Tables (One to many): Case ------------------ CaseID (int not null) MetaColumn1 (varchar) MetaColumn2 (varchar) MetaColumn3 (varchar) ... CaseInfo ------------------ CaseInfoID (int) CaseID (int nulls allowed) CaseInfoMeta (varchar) ... I'm new to LinqToSQL and am having trouble doing..

2019 Update / TLDR; switch to Entity Framework Core (or whatever else) While missing some "Features", EF Core properly honors Alternate Keys (aka Unique Constraints) in addition to Primary Keys and thus does a much better job of honoring Relational Algebra. YMMV otherwise; at least it supports many more SQL schemes correctly. This support added was in the (very outdated) EF Core 1.0 release .. a bit disappointing that the original EF never had this design(ed!) flaw addressed. This may be related to my other question - which seems to be that either: Entity Framework is a terrible Relational

I have a MySQL table whose definition is as follows: CREATE TABLE `guestbook` ( `Id` int(10) unsigned NOT NULL, `ThreadId` int(10) unsigned NOT NULL, PRIMARY KEY (`Id`), KEY `ThreadId` (`ThreadId`), CONSTRAINT `guestbook_ibfk_1` FOREIGN KEY (`ThreadId`) REFERENCES `guestbook` (`Id`) ) ENGINE=InnoDB; and currently there's only 1 row in the table: mysql> select * from guestbook; +-----+----------+ | Id | ThreadId | +-----+----------+ | 211 | 211 | +-----+----------+ The problem is that there's no way to delete this row without breaking the constraint. mysql> delete from guestBook; ERROR 1451

I have a model that defines mutually recursive tables: Answer questionId QuestionId text Question text correct AnswerId What do I need to do to actually insert a question? I need to know what the correct answer is first. But to insert an answer, I need to know what question it answers. I'm running Postgres, if it matters. The DDL is: CREATE TABLE answer ( id integer NOT NULL, -- answer id text character varying NOT NULL, -- answer text question_id bigint NOT NULL -- question id ); CREATE TABLE question ( id integer NOT NULL, -- question id question character varying NOT NULL, -- question text