NULL on joined columns

You know that NULL values on joined columns are omitted from comparision when tables are joined Consider this example Declare @t1 table ( col1 int , col2 varchar ( 10 )) insert into @t1 select 1 , 'test1' union all select 2 , 'test2' union all select NULL, 'test3' union all select 5 , ' test4' Declare @t2 table ( col1 int , col2 varchar ( 10 )) insert into @t2 select 1 , 'testing1' union all select 2 , 'testing2' union all select NULL, 'testing3'...(read more)

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