1.1我的结果集将是
--gets me all records with emp no 10
select * from table where empno = 10
--gets me all records excluding no 10
select * from table where empno <> 10
--what if empno column has null values...will my query pick null values???
select * from table where empno <> 10
adam 10
james 10
peter 10
adam 20
robert null
jacob null
john 10
？