Question

I have a rather weak understanding of any of oracle’s more advanced functionality but this should I think be possible.

Say I have a table with the following schema:

MyTable   Id INTEGER,   Col1 VARCHAR2(100),   Col2 VARCHAR2(100) 

I would like to write an sproc with the following

PROCEDURE InsertOrUpdateMyTable(p_id in integer, p_col1 in varcahr2, p_col2 in varchar2) 

Which, in the case of an update will, if the value in p_col1, p_col2 is null will not overwrite Col1, Col2 respectively

So If I have a record:

id=123, Col1='ABC', Col2='DEF'  exec InsertOrUpdateMyTable(123, 'XYZ', '098'); --results in id=123, Col1='XYZ', Col2='098' exec InsertOrUpdateMyTable(123, NULL, '098');  --results in id=123, Col1='ABC', Col2='098' exec InsertOrUpdateMyTable(123, NULL, NULL);   --results in id=123, Col1='ABC', Col2='DEF' 

Is there any simple way of doing this without having multiple SQL statements?

I am thinking there might be a way to do this with the Merge statement though I am only mildly familiar with it.

---

EDIT: Cade Roux bellow suggests using COALESCE which works great! Here are some examples of using the coalesce kewyord. And here is the solution for my problem:

MERGE INTO MyTable mt     USING (SELECT 1 FROM   DUAL) a     ON (mt.ID = p_id)     WHEN MATCHED THEN         UPDATE            SET mt.Col1 = coalesce(p_col1, mt.Col1), mt.Col2 = coalesce(p_col2, mt.Col2)     WHEN NOT MATCHED THEN         INSERT (ID, Col1, Col2)         VALUES (p_id, p_col1, p_col2); 

Answer 1

Using MERGE and COALESCE? Try this link for an example

with

SET a.Col1 = COALESCE(incoming.Col1, a.Col1)     ,a.Col2 = COALESCE(incoming.Col2, a.Col2)