Removing duplicates

 Select * from (

Select colA, ColB,.......ColZ,

Rank() over (partition by 

colA, ColB,.......ColZ

Order by

colA, ColB,.......ColZ) ranks

From Sales_Tab

)

TABLE_1

WHERE RANKS =1;

---------

Select * from (

Select colA, ColB,.......ColZ,

Rownum() over (partition by 

colA, ColB,.......ColZ

Order by

colA, ColB,.......ColZ) ranks

From Sales_Tab

)

TABLE_1

WHERE RANKS =1;

-----------------------------------------

Showing Duplicate values

Removing Duplicate Values;