How to find out whether a table has some unique columns

Question

I use MS SQL Server.

Ive been handed some large tables with no constrains on them, no keys no nothing.

I know some of the columns have unique values. Is ther

Answer 1

Here is I think probably the cleanest way. Just use dynamic sql and a single select statement to create a query that gives you a total row count and a count of distinct values for each field.

Fill in the DB name and tablename at the top. The DB name part is really important since OBJECT_NAME only works in the current database context.

use DatabaseName

DECLARE @Table varchar(100) = 'TableName'

DECLARE @SQL Varchar(max)

SET @SQL = 'SELECT COUNT(*) as ''Total'''

SELECT @SQL = @SQL + ',COUNT(DISTINCT ' + name + ') as ''' + name + ''''
FROM sys.columns c
WHERE OBJECT_NAME(object_id) = @Table

SET @SQL = @SQL + ' FROM ' + @Table

exec @sql