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POReturn multiple values and populate column in array like manner
 

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    <p>I am using Postgres 9.3 on MacOSX. </p> <p>I am wondering how I can return multiple values (depending on certain criterion) and use them to populate a column in a list/array like manner? </p> <pre><code>--DUMMY DATA CREATE TABLE tbl ( id VARCHAR(2) PRIMARY KEY ,name TEXT ,year_born NUMERIC ,nationality TEXT ); INSERT INTO tbl(id, name, year_born, nationality) VALUES ('A1','Bill',2001,'American') ,('B1','Anna',1997,'Swedish') ,('A2','Bill',1991,'American') ,('B2','Anna',2004,'Swedish') ,('B3','Anna',1989,'Swedish') ,('A3','Bill',1995,'American'); SELECT * FROM tbl; id | name | year_born | nationality ---+------+-----------+------------ A1 | Bill | 2001 | American B1 | Anna | 1997 | Swedish A2 | Bill | 1991 | American B2 | Anna | 2004 | Swedish B3 | Anna | 1989 | Swedish A3 | Bill | 1995 | American </code></pre> <p>I pool over column <code>name, nationality</code> by using <code>SELECT DISTINCT ON</code> clause as in the below code</p> <pre><code>CREATE TABLE another_tbl ( name TEXT, nationality TEXT, ids VARCHAR ); CREATE FUNCTION f1() RETURNS SETOF another_tbl AS $$ SELECT DISTINCT ON (name, nationality) name, nationality, id FROM tbl GROUP BY name, nationality, ID; $$ LANGUAGE sql SELECT * FROM f1(); name | nationality | ids ------+-------------+----- Anna | Swedish | B1 Bill | American | A1 </code></pre> <p>So, here is the thing which I do not know how to achieve, but which I reckon is fairly easy. I want column <code>ids</code> to be populated by all the id's corresponding to the names in the <code>name</code> column as seen below.</p> <p>Desired output:</p> <pre><code> SELECT * FROM f1(); name | nationality | ids ------+-------------+----- Anna | Swedish | B1, B2, B3 Bill | American | A1, A2, A3 </code></pre> <p><strong>Update</strong></p> <p>Found out about <code>ARRAY</code> which I use together with class <code>VARCHAR</code> for column <code>ids</code> in <code>another_tbl</code>. However, I get a mismatch call saying <code>Final statement returns character varying instead of</code>character varying[]<code>at column 3</code>.</p>
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