I have a language table (translations) with column names which are the language for the items in that column:
english spanish german etc.
I am joining that table to another table on an integer id.
I am trying to write a type statement and function where the name of the column is passed into the function. That language name appears in the select portion of the query:
#type
CREATE TYPE catCats AS (classid integer, varname text, color text, lang text);
#function
CREATE OR REPLACE FUNCTION listCategories(text) RETURNS SETOF catCats AS $$
SELECT DISTINCT(classid), varname, color, $1
FROM span_classes
LEFT JOIN translations ON translations.lid = span_classes.descript_tid
GROUP BY classid, varname, color, $1
ORDER BY classid ASC;
$$ LANGUAGE SQL;
#using the function
select * from listCategories(english);
If I pass in english or “english” it says column does not exist. If I pass in ‘english’ I get the literal english in my result set.
If I substitute the literal english (with no quotes) in place of the $1 in the function, the query returns the english values from the translations table correctly.
I’ve tried bytea for the datatype, as well as a table alias. I don’t know the language column until runtime so I can’t code it in the function.
What am I doing wrong?
