Oracle: how to INSERT if a row doesn't exist

oracle plsql
Topera picture Topera · Oct 1, 2010 · Viewed 120.8k times · Source

What is the easiest way to INSERT a row if it doesn't exist, in PL/SQL (oracle)?

I want something like:

IF NOT EXISTS (SELECT * FROM table WHERE name = 'jonny') THEN
  INSERT INTO table VALUES ("jonny", null);
END IF;

But it's not working.

Note: this table has 2 fields, say, name and age. But only name is PK.

Answer

Benoit picture Benoit · Oct 1, 2010 
INSERT INTO table
SELECT 'jonny', NULL
  FROM dual -- Not Oracle? No need for dual, drop that line
 WHERE NOT EXISTS (SELECT NULL -- canonical way, but you can select
                               -- anything as EXISTS only checks existence
                     FROM table
                    WHERE name = 'jonny'
                  )

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