Jul 5, 2011 · The users are importing data from various external systems so ContactId will not be unique across the board but will be unique on a per user basis. I know how to create Unique …

173 I have SQL Server 2008 R2 and I want to set a unique column. There seems to be two ways to do this: "unique index" and "unique constraint". They are not much different from what I …

Mar 31, 2011 · ALTER TABLE [dbo]. [tablename] DROP CONSTRAINT [unique key created by sql] GO alternatively: go to the keys -- right click on unique key and click on drop constraint in …

Apr 20, 2009 · I want to have a unique constraint on a column which I am going to populate with GUIDs. However, my data contains null values for this columns. How do I create the constraint …

Now, a unique index and a unique constraint happen to be implemented the same way under the covers in SQL Server, so this is just semantics. But your documentation should explain why …

Apr 6, 2010 · 6 Unique constraints are for all rows, and there is no way to specify only some rows. Check constraints are only for validation within a single row. The only ways to achieve your …

Dec 18, 2015 · sql-server-2005 unique-constraint edited May 3, 2012 at 20:37 Mark Sowul 10.7k 1 49 52

Aug 20, 2009 · The UNIQUE constraint uniquely identifies each record in a database table. The UNIQUE and PRIMARY KEY constraints both provide a guarantee for uniqueness for a …

Apr 29, 2017 · For example you will have the unique table with an ID, AppName and ItemName to make up its 3 columns. Then have this table link to the others. For how to do this here is a …

Mar 23, 2010 · FROM sys.objects WHERE type_desc LIKE '%CONSTRAINT' AND OBJECT_NAME(OBJECT_ID)='XYZ' If you need even more constraint information, look inside …