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[nycphp-talk] input..select help

Scott Mattocks crisscott at netzero.com
Mon May 10 13:00:47 EDT 2004


Rahmin Pavlovic wrote:

> insert into table_b(field1,field2) select table_a.field1, table_a.field2 from table_a
> 
> Which worked fairly quickly, however it also imported entries from table_a that already exist in table_b.
> So I'm wondering if someone could help me figure out how to just grab the new entries from table_a.

Try something like this:

INSERT INTO table_b (field1, field2)
(SELECT table_a.field1, table_a.field2
  FROM table_a
   LEFT JOIN table_b
    ON (table_a.field1 = table_b.field1
        AND
        table_a.field2 = table_b.field2)
  WHERE table_b.field1 IS NULL
   AND table_b.field2 IS NULL)

I would try the select first to make sure that it will get you 
everything in table_a that isn't already in table_b.  And then if you 
like the results from that add the insert part to the begining.

Scott Mattocks



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