I have a "comments" table that models a conversation on a topic, like this: id serial topic_id integer parent_comment_id integer body text So, every comment has a reference to its topic AND ...
In this one project I am working on, I need to set a particular field to be unique (not a problem!) but if the field is null I want the constraint to be ignored. In Sql Server 2008 I use filtered ...
When I want a column to have distinct values, I can either use a constraint create table t1( id int primary key, code varchar(10) unique NULL ); go or I can use a unique index create table t2( id ...
I have a table with a FILESTREAM column, and it has two unique constraints specified for the same FILESTREAM column, ie: ALTER TABLE [dbo].[TableName] ADD CONSTRAINT ...