How to sort the result from string_agg()
SqlPostgresqlString AggregationSql Problem Overview
I have a table:
CREATE TABLE tblproducts
(
productid integer,
product character varying(20)
)
With the rows:
INSERT INTO tblproducts(productid, product) VALUES (1, 'CANDID POWDER 50 GM');
INSERT INTO tblproducts(productid, product) VALUES (2, 'SINAREST P SYP 100 ML');
INSERT INTO tblproducts(productid, product) VALUES (3, 'ESOZ D 20 MG CAP');
INSERT INTO tblproducts(productid, product) VALUES (4, 'HHDERM CREAM 10 GM');
INSERT INTO tblproducts(productid, product) VALUES (5, 'CREAM 15 GM');
INSERT INTO tblproducts(productid, product) VALUES (6, 'KZ LOTION 50 ML');
INSERT INTO tblproducts(productid, product) VALUES (7, 'BUDECORT 200 Rotocap');
If I execute string_agg() on tblproducts:
SELECT string_agg(product, ' | ') FROM "tblproducts"
It will return the following result:
CANDID POWDER 50 GM | ESOZ D 20 MG CAP | HHDERM CREAM 10 GM | CREAM 15 GM | KZ LOTION 50 ML | BUDECORT 200 Rotocap
How can I sort the aggregated string, in the order I would get using ORDER BY product?
I'm using PostgreSQL 9.2.4.
Sql Solutions
Solution 1 - Sql
With postgres 9.0+ you can write:
select string_agg(product,' | ' order by product) from "tblproducts"
Solution 2 - Sql
https://docs.microsoft.com/en-us/sql/t-sql/functions/string-agg-transact-sql?view=sql-server-2017
SELECT
STRING_AGG(prod, '|') WITHIN GROUP (ORDER BY product)
FROM ...
Solution 3 - Sql
select string_agg(prod,' | ') FROM
(SELECT product as prod FROM tblproducts ORDER BY product )MAIN;