postgresql資料庫如何檢視我自己建立的function呢

SELECT

pg_proc.proname AS "函數名稱",

pg_type.typname AS "傳回值資料類型",

pg_proc.pronargs AS "參數個數"

FROM

pg_proc

JOIN pg_type           

ON (pg_proc.prorettype = pg_type.oid)

WHERE

pg_type.typname != 'void'

AND pronamespace = (SELECT pg_namespace.oid FROM pg_namespace WHERE nspname = 'public');

函數名稱          | 傳回值資料類型 | 參數個數           

_group_concat	text	2
film_in_stock	int4
film_not_in_stock
last_day	date	1
last_updated	trigger
get_sum	numeric
get_customer_balance
inventory_held_by_customer
inventory_in_stock	bool
rewards_report	customer
group_concat

(11 行記錄)