I’m looking for a way to sequentially number rows in a result set (not a table). In essence, I’m starting with a query like the following:
SELECT id, name FROM people WHERE name = 'Spiewak'
The ids are obviously not a true sequence (e.g. 1, 2, 3, 4). What I need is another column in the result set which contains these auto-numberings. I’m willing to use a SQL function if I have to, but I would rather do it without using extensions on the ANSI spec.
Platform is MySQL, but the technique should be cross-platform if at all possible (hence the desire to avoid non-standard extensions).
To have a meaningful row number you need to order your results. Then you can do something like this:
Note that the WHERE clause of the sub query needs to match the WHERE clause or the primary key from the main query and the ORDER BY of the main query.
SQL Server has the ROW_NUMBER() OVER construct to simplify this, but I don’t know if MySQL has anything special to address it.
Since my post here was accepted as the answer, I want to also call out Dan Goldstein’s response, which is very similar in approach but uses a JOIN instead of a sub query and will often perform better