Need Help Can i use Merge command along with exist function in oracle?

Question

I am using Merge command to update the destination table and updating the rows which are already in the destination table.
But what i want is to delete the existing rows from the destination table and insert fresh rows instead of updating the existing rows in the destination table.
So can we use exist function to check the existing rows and delete them and use merge command to insert the rows in the table.

Answer 1

You definitely need to do a DELETE then INSERT since MERGE will not delete rows, although I'm not really sure what that gets you since the net effect would be the same as a MERGE over the same pair of tables.
If you really want to do it this way, then I would likely do something like:
DELETE FROM target_table
WHERE (columns_you_would_match_on) IN (SELECT columns_you_would_match_on
                                       FROM source_table
                                       WHERE predicate_you_would_use_in_using);
INSERT INTO target_table (column_list)
SELECT column_list
FROM source_table
WHERE predicate_you_would_use_in_using;John