CODEWITHSUNDEEP
sqlsqlite
leftspin
leftspin

Reputation: 2488

SQL: check to see which id's already exist

Let's say I have a list of IDs and I want to see if rows already exist with those IDs in my SQL database. Is there a single SQL command that I can issue to get back the subset of the ID list that's not already represented in the database? I could iterate over each ID in my code and issue a separate SQL check for each ID, but that sounds inefficient.

I'm trying to do this against an sqlite database. thanks!

Upvotes: 3

Views: 493

Answers (2)

Tangent 128
Tangent 128

Reputation: 536

You could use the IN operator; for instance, to test for ids 1, 2, 8, and 42, you'd do:

SELECT id
FROM tbl
WHERE id IN (1, 2, 8, 42);

Upvotes: 0

Will A
Will A

Reputation: 24998

Drop the IDs into a table and then try:

SELECT C.id
FROM checkids C
LEFT JOIN mytable M
ON M.id = C.id
WHERE M.id IS NULL

Upvotes: 3

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