INSERT INTO if not exists SQL server

Question

I have a database structured as follows:

users

userid (Primary Key)
username

group

Answer 1

There is a simple solution! I Found it in this post!

INSERT INTO users (Username) 
SELECT ('username')
WHERE NOT EXISTS(SELECT * FROM users WHERE Username= 'username')

In my project I needed to do it with 2 values. So my code was:

INSERT INTO MyTable (ColName1, ColName2) 
SELECT 'Value1','Value2' 
WHERE NOT EXISTS
(SELECT * FROM MyTable WHERE ColName1 = 'Value1' AND ColName2= 'Value2')

Hope this helps!