SQL & PL/SQL :: How To Write Function To Find Unique Value In Table

Create a function which will indicate if a given record in a table is unique or not. Unique means the data is occurring only once in the entire table.

Function should be in this signature

function IS_UNIQUE (tableName in varchar2,tableAttribute in varchar2)
return number
.....
begin
//logic to check if given data is unique
return 0; //return 0 if data is unique
else
return 1; //return 1 if data is duplicate
end;

Once I run this query

select attribute1 from table1 where IS_UNIQUE(table1,attribute1)=0

All records of attribute1 which are unique need to be fetched. Similarly, select attribute1 from table1 where IS_UNIQUE(table1,attribute1)=1 should return all records of attribute1 which are duplicates.