Re: How to search for composite type array - Mailing list pgsql-general

I want to have an array of composite type in a table. Retrieving/saving value work fine.

I just wonder how I can search against composite type array.

CREATE TYPE CompXYZ AS (

         attr1         integer,

         attr2         text,

         attr3         inet

);

CREATE TABLE sample (

         id             integer not null primary key,

         list           CompXYZ[]

);

insert into sample values (1, '{"(1,abc,127.0.0.1)", "(5,def,10.0.1.2)"}');

insert into sample values (2, '{"(10,hello,127.0.0.1)", "(20,def,10.0.1.2)"}');

insert into sample values (3, '{"(20,hello,10.1.1.1)", "(30,there,10.1.1.2)"}');

How I can search a row containing "hello" for attr2?

I know if I have a separate table for saving 3 attributes along with foreign key to sample table, then I can achieve my goal.

I just want to know if there is a way to do the same thing using composite array.

Thank you,

Choon Park

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SELECT * FROM sample WHERE id IN (

SELECT id FROM (

SELECT id, unnest(list) AS list_item FROM sample

) explode  --need to unnest the array so you can address individual parts of the composite type in the where clause

WHERE (explode.list_item).text = ‘hello’ –note the () are required around (table.column), even if table is omitted; i.e., “(list_item).text”

) --/IN

In may be worth it to define a

text = CompXYZ   

custom equality function+operator then you could do this (in theory…):

… WHERE ‘hello’ = ANY(list)

Your main issue is that the ANY/ALL array operators operating on whole elements.

Tweak the above to output whatever specific data you need as written it outputs a single record from sample if any of the contained array elements matches.

David J.