Question

Is there a way in MySQL to COUNT(*) from a table where if the number is greater than x, it will stop counting there? Basically, I only want to know if the number of records returned from a query is more or less than a particular number. If it’s more than that number, I don’t really care how many rows there are, if it’s less, tell me the count.

I’ve been able to fudge it like this:

-- let x be 100

SELECT COUNT(*) FROM (
    SELECT `id` FROM `myTable`
    WHERE myCriteria = 1
    LIMIT 100
) AS temp

…but I was wondering if there was some handy built-in way to do this?

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Thanks for the suggestions, but I should have been more clear about the reasons behind this question. It’s selecting from a couple of joined tables, each with tens of millions of records. Running COUNT(*) using an indexed criteria still takes about 80 seconds, running one without an index takes about 30 minutes or so. It’s more about optimising the query rather than getting the correct output.

Answer 1

SELECT * FROM WhateverTable WHERE WhateverCriteria
LIMIT 100, 1

LIMIT 100, 1 returns 101th record, if there is one, or no record otherwise. You might be able to use the above query as a sub-query in EXIST clauses, if that helps.