Filter in SQL server

 1. Remove duplicate:

 Use Distinct:

Select Distinct column1,column1 from table

Distinct With Null value

It returns one null value

Group by and Distinct

Both returns same value if we don't use aggregate in group by

Where Clause

Where clause work use with many operators 

=,!=,like, not like, is null, is not null, in , exist ,not exist,>,<,>=,<=

Multiple Condition in SQL:

and , or