DELETE FROM ... reporting syntax error at or near "."

Question

I'm trying to delete just one data from my DB, but, when I write the command I keep getting that there's some syntax error, could you tell me where is the error?

This are the commands I've tried:

DELETE FROM database_userprofile WHERE user.username = 'some';
ERROR:  syntax error at or near "."
LINE 1: DELETE FROM database_userprofile WHERE user.username = 'some'...

DELETE FROM database_userprofile USING database_user WHERE user.username="some";
ERROR:  syntax error at or near "."
LINE 1: ... database_userprofile USING database_user WHERE user.username=...

Hope you can help me

Answer 1

Your query doesn't make any sense.

DELETE FROM database_userprofile WHERE user.username = 'some';
                                       ^^^^

Where'd user come from? It isn't referenced in the query. Is it a column of database_userprofile? If so, you can't write user.username (unless it's a composite type, in which case you would have to write (user).username to tell the parser that; but I doubt it's a composite type).

The immediate cause is that user is a reserved word. You can't use that name without quoting it:

DELETE FROM database_userprofile WHERE "user".username = 'some';

... however, this query still makes no sense, it'll just give a different error:

regress=> DELETE FROM database_userprofile WHERE "user".username = 'some';
ERROR:  missing FROM-clause entry for table "user"
LINE 1: DELETE FROM database_userprofile WHERE "user".username = 'so...

My wild guess is that you're trying to do a delete over a join. I'm assuming that you have tables like:

CREATE TABLE "user" (
    id serial primary key,
    username text not null,
    -- blah blah
);

CREATE TABLE database_userprofile (
     user_id integer references "user"(id),
     -- blah blah
);

and you're trying to do delete with a condition across the other table.

If so, you can't just write user.username. You must use:

DELETE FROM database_userprofile
USING "user"
WHERE database_userprofile.user_id = "user".id
AND "user".username = 'fred';

You'll notice that I've double-quoted "user". That's because it's a keyword and shouldn't really be used for table names or other user defined identifiers. Double-quoting it forces it to be intepreted as an identifier not a keyword.