How to combine two queries in to the one line query

Question

I want to using the first query result to apply on the second query. Then I got some problems.

(My environment is Node.js , but it doesn't cause the influence of this question.)

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FIRST QUERY

SELECT (TO_SECONDS('2015-02-10 23:00:00') - TO_SECONDS(NOW())) AS remainSeconds

then I will get the numeric result 'remainSeconds' like '-1957'.

If 'remainSeconds' > 0 will run the second query.

SECOND QUERY

// '...' is not important, so I skip them.

INSERT INTO tableA(...) SELECT ... FROM tableB

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My problem summary :

We know there is some delay between the two queries running. And this delay time will cause some critical problems in some cases.

How to combine above two queries in to the one line query.

Answer 1

Just add the (TO_SECONDS('2015-02-10 23:00:00') - TO_SECONDS(NOW())) in the where of your SELECT

eg

INSERT INTO tableA(...) SELECT ... FROM tableB WHERE (TO_SECONDS('2015-02-10 23:00:00') - TO_SECONDS(NOW())) > 0