Re: Casting a collation in an ORDER BY ... COLLATE

Kip Cole <kipcole9(at)gmail(dot)com> writes:
> cldr_sql=# select * from models order by name collate 'en-x-icu'::regcollation;
> ERROR: syntax error at or near "'en-x-icu'"
> LINE 1: select * from models order by name collate 'en-x-icu'::regco…

You've got the syntax off a bit. The argument of COLLATE is an
identifier, not a string literal (or expression), so you should write

select * from models order by name collate "en-x-icu";

The double quotes are needed because most collation names don't
follow SQL identifier rules.

> Utilmately the objective is to interpolate the collation value into a prepared query so
> this is just the first step to validate that casting a COLLATE name is possible or not.

If you mean that you want to inject a run-time-variable collation
name, you can't, any more than you can inject (say) a run-time-variable
table name. You'd have to construct and execute a dynamic SQL string.

regards, tom lane