Changing a null string to an empty string in select statment

sql-server

Solution

Check out ISNULL() in the SQL Server Books Online.

Syntax:

ISNULL ( check_expression , replacement_value )

Example:

Select ISNULL(myfield1,'') from mytable1

Problem

I have a SQL Server 2005 table that has a string column in which empty values are sometimes stored as `NULL` and other times as an empty string. I am doing a `SELECT DISTINCT` on this column and I am getting all the distinct values + NULL + empty string. But what I would like is to check if the value is NULL and return an empty string instead. So the result set would be all the distinct values + empty string (if any values were null or an empty string). But how can I do this in a SELECT statement?

Original source