Re: Comparing keys in two tables

[mysql]

Aaron Fischer wrote:
> Greetings!
> 
> I have a problem that it seems would best be solved using  subqueries.  
> However, I am working on a server that is running MySQL  3.23.58, so 
> subqueries are not available to me.
> 
> What I am trying to do:
> I have two tables, each containing approximately 37,000 records.  I  
> want to compare the index field in Table A to the index field in  Table 
> B.  I would like to see all records where the index in Table A  does not 
> exist in Table B.
> 

You want to select from A, not from B, yes?

SELECT a.* FROM foo AS a
LEFT OUTER JOIN bar AS b
ON a.index_field = b.index_field
WHERE b.index_field IS NULL;

brian