如何小写postgresql数组？

Question

I need to lowercase array content in PostgreSQL, lower(array['array_content'])) or array[lower('array_content'])) does not work. Actual array is much, much longer.

SELECT * FROM kliendi_aadress WHERE lower(linn) LIKE ANY (array['Tallinn', 'Tartu','Narva'])

Can this even be done?

Answer 1

好吧，ILIKE为我解决了这个问题

SELECT * FROM kliendi_aadress WHERE linn ILIKE ANY (array['Tallinn', 'Tartu','Narva']);

Answer 2

the first that come to mind is ugly:

db=# select lower(array['Tallinn', 'Tartu','Narva']::text)::text[];
         lower
-----------------------
 {tallinn,tartu,narva}
(1 row)

Here I lower text representation of your array and then cast it back to array.

And so comparison:

db=# select 'tartu' = any (lower(array['Tallinn', 'Tartu','Narva']::text)::text[]);
 ?column?
----------
 t
(1 row)

Answer 3

The citext extension can come in handy in this situation.

-- If you haven't enabled citext in your DB
CREATE EXTENSION citext;
select 'tartu' = any (array['Tallinn', 'Tartu','Narva']::citext[])

should work.