项目中,希望实现返回select内容 后来通过bing.com查询,其实我需要的是返回表格。也是pq中的table,下面是demo CREATEORREPLACEFUNCTIONword_frequency(_max_tokensint)RETURNSTABLE( txt text ,abs_cntbigint,relative_sharenumeric)AS$func$BEGINRETURNQUERYSELECTt.txt ,t.cnt ,round((t.cnt*100)/(sum(t.cnt)OVER...
postgresqlfunction返回select pq函数功能很强⼤，我打算把统计的功能都放在数据库端。优势让运算离数据更近⼀些，缺点⽆法服⽤代码。牺牲了django的灵魂性，项⽬必须依赖postgresql。项⽬中，希望实现返回select内容 后来通过bing.com查询，其实我需要的是返回表格。也是pq中的table，下⾯是demo CREATE OR ...
percent = (SELECT 1/cnt FROM (SELECT count(*) AS cnt FROM example_table AS x WHERE x.fn_key_1 = example_table.fn_key_1 AND x.fn_key_2 = example_table.fn_key_2) AS tmp WHERE cnt > 0)那个会慢一点。 我正在考虑基于窗口函数的解决方案，您可能也想探索它们。
In plpgsql code,SELECTwithout a target triggers an error. But you obviously donotwantSELECT INTO, you just want to set the status ofFOUND. You would usePERFORMfor that. SELECT raises exception in PL/pgSQL function Better, yet, useIF EXISTS ... Consider this rewrite of your function: CREA...
Is there a difference between a plain SQL function doing a SQL query: create function get_sports() returns setof sport as $body$ select * from sport; $body$ language sql stable; and PLPGSQL function returning that same SQL query: create function get_sports() returns setof spo...
CREATE OR REPLACE function func(age bigint) RETURNS TABLE(years int, category text) AS $$ SELECT CASE WHEN age > 30 THEN SELECT CASE WHEN (age >= 60) THEN 0 WHEN (age >= 50) THEN 10 WHEN (age >= 40) THEN 20 ELSE 30 END, CASE WHEN (age >= 60) THEN ...
create or replace function db_stat.process_snapshot_table(in i_host_ip cidr,in i_host_port int,in i_host_type varchar,in i_comment varchar default '') returns int as $$ declare v_snapid int; _detail text; _hint text; _message text; ...
idn_dw=> select concat(round(4::numeric/5*100),'%'); concat --- 80% (1 row) 完事。 補充:使用postgresql的round()四舍五入函數報錯 需求: 使用postgresql的round()四舍五入保留兩位小數 報錯: HINT: No function matches the given name and argument types. You might 解決方案...
I have an expensive function f(x, y) on two columns x and y in my database table. I want to execute a query that gives me the result of the function as a column and puts a constraint on it, something like SELECT *, f(x, y) AS func FROM table_name WHERE func < 10; Howeve...
CREATE FUNCTION "random_move" () RETURNS "move" LANGUAGE sql AS $$ SELECT move FROM unnest(enum_range(NULL::move)) move ORDER BY random() LIMIT 1; $$; -- Create "play" function CREATE FUNCTION "play" ("player" "move") RETURNS text LANGUAGE plpgsql AS $$ ...