2010年2月11日 · user_id in messages table is a fk field so it has to make clear which id is (user_id). a fully-self-explaining naming convention, in my opinion, could be: fk_[referencing …

2014年1月14日 · To do this without knowing the constraint's name and without inner joins, you can do: IF NOT EXISTS(SELECT NULL FROM …

2009年5月29日 · select fk_table = fk.table_name, fk_column = cu.column_name, pk_table = pk.table_name, pk_column = pt.column_name, constraint_name = c.constraint_name from …

Practically, it depends on how many tables have the FK definitions included. If someone bothered to carefully define all FK references -- and the SELECT statements stick to these rules -- you …

2016年9月21日 · sp_rename 'HumanResources.FK_Employee_Person_BusinessEntityID', 'FK_EmployeeID'; will rename FK_Employee_Person_BusinessEntityID found in the …

2010年6月1日 · @Kangkan creating FK have nothing to do with performance FK != Indexes. There are DBMS automatic creates a index in the FK creation but most don't. Joins don't need …

2013年8月26日 · Consider the case of a Customer table with a SSN column (and a dumb primary key), and a Claim table that also contains a SSN column (populated by business logic from the …

2009年1月27日 · IF (OBJECT_ID('dbo.FK_ConstraintName', 'F') IS NOT NULL) BEGIN ALTER TABLE dbo.TableName DROP CONSTRAINT FK_ConstraintName END If you need to drop …

However, it makes a lot of sense to index all the columns that are part of any foreign key relationship. An FK-relationship will often need to look up a relating table and extract certain …

YES, a FK can speed up SELECT but slow down INSERT/UPDATE/DELETE. SQL Server uses all constraints (FK included) to build better execution plans for SELECTs. For instance, if you …