Syntax error near CASE on postgres function

Question

CREATE OR REPLACE FUNCTION public.defaultmapviewport(hasura_session json)
 RETURNS viewport_info
 STABLE
AS $function$
    case hasura_session ->> 'x-hasura-default-country-code'
        when 'FR' then select lat, lng from places where slug_en = 'city-paris' 
        when 'ES' then select lat, lng from places where slug_en = 'municipality-madrid'
    end;
END $function$ language SQL;

I'm getting a syntax error near case, even though it seems right. What could be the problem?

Viewport info:

create table viewport_info(
    lat float,
    lng float
);

`CASE` cannot exist on its own, it needs to be part of larger query e.eg. `SELECT CASE ...`. In other words you inverted the statement. See [CASE](https://www.postgresql.org/docs/current/functions-conditional.html#FUNCTIONS-CASE). — Adrian Klaver, Dec 29 '21 at 19:59

Bergi · Accepted Answer · 2021-12-29T20:33:57.700

2

As @AdrianKlaver commented, a CASE expression can't stand on its own, it must be part of a SELECT query. You'll want to use

CREATE OR REPLACE FUNCTION public.defaultmapviewport(hasura_session json)
RETURNS viewport_info
STABLE
AS $function$
  SELECT lat, lng
  FROM places
  WHERE slug_en = (CASE hasura_session ->> 'x-hasura-default-country-code'
    WHEN 'FR' THEN 'city-paris' 
    WHEN 'ES' THEN 'municipality-madrid'
  END);
$function$ language SQL;

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edited Dec 29 '21 at 20:33

answered Dec 29 '21 at 20:03

Bergi

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i'm getting a return type mismatch in function declared to return viewport_info, I'll update question with the viewport_info create statement – PlayMa256 Dec 29 '21 at 20:09
1

@PlayMa256 Ah, there was a stray `END` at the end that I copied from the question. Fixed! – Bergi Dec 29 '21 at 20:35

Syntax error near CASE on postgres function

1 Answers1