Tuesday, April 10, 2012

SQL: how do you look for missing ids?

Suppose I have a table with lots of rows identified by a unique ID. Now I have a (rather large) user-input list of ids (not a table) that I want to check are already in the database.



So I want to output the ids that are in my list, but not in the table. How do I do that with SQL?



EDIT: I know I can do that with a temporary table, but I'd really like to avoid that if possible.



EDIT: Same comment for using an external programming language.





1 comment:

  1. Try with this:

    SELECT t1.id FROM your_list t1
    LEFT JOIN your_table t2
    ON t1.id = t2.id
    WHERE t2.id IS NULL

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