Question

I’m trying to sort by converted column, but psql returns error:

SELECT * FROM table ORDER BY CONVERT(col1 USING
utf8_to_iso_8859_2);

ERROR: syntax error at or near “USING” LINE 1: SELECT * FROM
table ORDER BY CONVERT(col1 USING utf8…
^

*** Error ***

ERROR: syntax error at or near “USING” SQL state: 42601

I saw this function used liked this before and it’s in documentation too, so I don’t understand why I’m getting this error. Anything I missed?

Answer 1

It looks like you are mixing two features. One is collation support, that would make sense in an ORDER BY clause:

SELECT * FROM table ORDER BY col1 COLLATE "fr_FR";

The other one is the convert() function that transcodes a string from a source encoding to a defined destination encoding:

SELECT convert('my_string', 'UTF8', 'ISO_8859_2')

But that has no effect on the sort order – except with locale C or a bytea column.