CREATE FUNCTION test(VARIADIC arr text[])
RETURNS TABLE (data_time TIMESTAMPTZ, id text, data jsonb)
AS 'SELECT data_timestamp, key, value
FROM hit_count
CROSS JOIN jsonb_each(data)
WHERE key = ALL ($1)'
LANGUAGE SQL;
If I call the function above with select test('123') it works fine. If I call it with select test('123','234') it returns nothing ie
test
------
(0 rows)
However if I define it as
CREATE FUNCTION test(VARIADIC arr text[])
RETURNS TABLE (data_time TIMESTAMPTZ, id text, data jsonb)
AS 'SELECT data_timestamp, key, value
FROM hit_count
CROSS JOIN jsonb_each(data)
WHERE key != ALL ($1)'
LANGUAGE SQL;
then the function returns all the data but those that fit the condition
Any ideas??
ALL was used as opposed to ANY the corrected function looks like this
CREATE FUNCTION test(VARIADIC arr text[])
RETURNS TABLE (data_time TIMESTAMPTZ, id text, data jsonb)
AS 'SELECT data_timestamp, key, value
FROM hit_count
CROSS JOIN jsonb_each(data)
WHERE key = ANY ($1)'
LANGUAGE SQL;
Related
I have a function that returns the result of a select based on a parameter being passed to it. I would like to join the parameter to the returned result of the function. Here's an example:
create or replace function somefunc(param varchar)
returns table(fielda varchar, fieldb int, param varchar)
language plpgsql
as $$
begin
return query
select
fielda varchar,
fieldb int,
param varchar -- HOW DO I SELECT IT?
from
sometable
join
othertable on id = other_id
end;
$$
You just need to call the parameter correctly
I created a fake sometable table and inserted two rows with
create table sometable(fielda varchar, fieldb int);
insert into sometable values('a',1);
insert into sometable values('b',2);
Then specified the somefunc function with
create or replace function somefunc(param_in varchar)
returns table(fielda varchar, fieldb int, param varchar)
language plpgsql
as $$
begin
return query
select
sometable.fielda,
sometable.fieldb,
param_in
from sometable;
end;
$$
Check out the param_in input parameter not in contrast with the param field in the table. I removed the join with the othertable but that can also be added.
I am very new to Postgres SQL. My requirement is to pass a dynamic number of columnId, columnValue pair and insert this combination in a table(Example: employeeId, employeeName combination). The length of list can be anything. I am thinking of building dynamic query at the code-side and pass it as string to function and execute the statement. Is there any better approach for this problem. Any example or idea will be much appreciated.
If you are allowed to pass that information as a structured JSON value, this gets quite easy. Postgres has a feature to map a JSON value to a table type using the function json_populate_record
Sample table:
create table some_table
(
id integer primary key,
some_name text,
some_date date,
some_number integer
);
The insert function:
create function do_insert(p_data text)
returns void
as
$$
insert into some_table (id, some_name, some_date, some_number)
select (json_populate_record(null::some_table, p_data::json)).*;
$$
language sql;
Then you can use:
select do_insert('{"id": 42, "some_name": "Arthur"}');
select do_insert('{"id": 1, "some_value": 42}');
Note that columns that are not part of the passed JSON string are explicitly set to NULL using this approach.
If the passed string contains column names that do not exist, they are simply ignored, so
select do_insert('{"id": 12, "some_name": "Arthur", "not_there": 123}');
will ignore the not_there "column".
Online example: https://rextester.com/JNIBL25827
Edit
A similar approach can be used for updating:
create function do_update(p_data text)
returns void
as
$$
update some_table
set id = t.id,
some_name = t.some_name,
some_date = t.some_date,
some_number = t.some_number
from json_populate_record(null::some_table, p_data::json) as t;
$$
language sql;
or using insert on conflict to cover both use cases with one function:
create function do_upsert(p_data text)
returns void
as
$$
insert into some_table (id, some_name, some_date, some_number)
select (json_populate_record(null::some_table, p_data::json)).*
on conflict (id) do update
set id = excluded.id,
some_name = excluded.some_name,
some_date = excluded.some_date,
some_number = excluded.some_number
$$
language sql;
I'm trying to use a plgSQL witch return me a record type :
CREATE FUNCTION actu(id INTEGER) RETURNS RECORD AS $$
DECLARE
ret RECORD;
BEGIN
SELECT id_photo, id_user, lien, titre
FROM photo
WHERE id_user IN (
SELECT id_userabo
FROM abo
WHERE id_user = id )
ORDER BY date_publi DESC LIMIT 10;
RETURN ret;
END;$$
LANGUAGE plpgsql;
When I'm trying to use it with :
SELECT * FROM actu(4)
AS (id_photo Integer, id_photo Integer, lien Varchar, titre Varchar);
pgAdmin4 send me error :
ERROR: ERROR: the request has no destination for the resulting data
HINT: If you want to cancel the results of a SELECT, use PERFORM instead.
CONTEXT: PL/pgsql function fil_actu(integer), line 5 with SQL statement
The immediate error is, that the result of a select statement needs to be stored somewhere (that's what the error says). You would need to use select .. into ret from ... to store the result, but that wouldn't work as a variable of type record can only store one row from a result.
You apparently want to return more than just one row, so you need to define the function as returns table() and then use return query in PL/pgSQL to return the result of a query. But for a simple function encapsulating a SELECT query, a language sql function is more efficient.
CREATE FUNCTION actu(id INTEGER)
-- adjust the data types for the returned columns!
RETURNS table (id_photo int, id_user int, lien text, titre text)
AS $$
SELECT id_photo, id_user, lien, titre
FROM photo
WHERE id_user IN (SELECT id_userabo
FROM abo
WHERE id_user = id )
ORDER BY date_publi DESC
LIMIT 10;
$$
LANGUAGE sql;
You can use that function like this:
select *
from actu(42);
You may define those types inside the function, but with different names for the types. The return type can be a TABLE type and use RETURN QUERY to return the results.
CREATE FUNCTION actu(id INTEGER) RETURNS TABLE
(typ_id_photo Integer, typ_id_user Integer, typ_lien Varchar, typ_titre Varchar)
AS $$
BEGIN
RETURN QUERY
SELECT id_photo, id_user, lien, titre
FROM photo p
WHERE id_user IN (SELECT id_userabo
FROM abo
WHERE id_user = id )
ORDER BY date_publi DESC
LIMIT 10;
END;$$
LANGUAGE plpgsql;
I have the table with some columns:
--table
create table testz
(
ID uuid,
name text
);
Note: I want to insert ID values by passing as a parameter to the function. Because I am generating the ID value
in the front end by using uuid_generate_v4(). So I need to pass the generated value to the function to insert
into the table
My bad try:
--function
CREATE OR REPLACE FUNCTION testz
(
p_id varchar(50),
p_name text
)
RETURNS VOID AS
$BODY$
BEGIN
INSERT INTO testz values(p_id,p_name);
END;
$BODY$
LANGUAGE PLPGSQL;
--EXECUTE FUNCTION
SELECT testz('24f9aa53-e15c-4813-8ec3-ede1495e05f1','Abc');
Getting an error:
ERROR: column "id" is of type uuid but expression is of type character varying
LINE 1: INSERT INTO testz values(p_id,p_name)
You need a simple cast to make sure PostgreSQL understands, what you want to insert:
INSERT INTO testz values(p_id::uuid, p_name); -- or: CAST(p_id AS uuid)
Or (preferably) you need a function, with exact parameter types, like:
CREATE OR REPLACE FUNCTION testz(p_id uuid, p_name text)
RETURNS VOID AS
$BODY$
BEGIN
INSERT INTO testz values(p_id, p_name);
END;
$BODY$
LANGUAGE PLPGSQL;
With this, a cast may be needed at the calling side (but PostgreSQL usually do better automatic casts with function arguments than inside INSERT statements).
SQLFiddle
If your function is that simple, you can use SQL functions too:
CREATE OR REPLACE FUNCTION testz(uuid, text) RETURNS VOID
LANGUAGE SQL AS 'INSERT INTO testz values($1, $2)';
Example: I am passing two parameters to function namely n(case number) and tname(table name), and want to display rows accordingly.
--Table "testing"
create table testing
(
rollno integer,
fname text,
lname text,
age integer,
branch text,
phno integer,
email text,
address text,
city text,
state text,
country text
)
--Rows insertion
insert into testing values(1,'aaa','bbb',25,'CS',1234567890,'abc#gmail.com','sector1','xyz','zyx','yxz');
insert into testing values(2,'zzz','xxx',25,'EE',987654321,'zzz#gmail.com','sector2','uvw','wvu','vuw');
--Function "f1()"
create or replace function f1(n integer,tname varchar)/*n for case number and tname for table name */
returns setof tname as
$body$
begin
case n
when 1 then
return query execute format ($$ select rollno,fname from %I $$,tname);
when 2 then
return query execute format ($$ select lname,age,branch from %I $$,tname);
when 3 then
return query execute format ($$ select phno,email,address,city,country from %I $$,tname);
end case;
end
$body$
language plpgsql;
--Function calling
select * from f1(1,'testing');
/*Show only case "1" select query result*/
select * from f1(2,'testing');
/*Show only case "2" select query result*/
select * from f1(3,'testing');
/*Show only case "3" select query result*/
While Craig is correct that return types cannot be dynamic in function declarations, there is a way around this with polymorphic types. This is surprisingly simple and would actually work flawlessly:
CREATE OR REPLACE FUNCTION data_of(_tbl_type anyelement)
RETURNS SETOF anyelement AS
$func$
BEGIN
RETURN QUERY EXECUTE 'SELECT * FROM '|| pg_typeof(_tbl_type);
END
$func$ LANGUAGE plpgsql;
Call (important!):
SELECT rollno,fname FROM data_of(NULL::testing);
SELECT * FROM data_of(NULL::my_schema.my_table);
SELECT * FROM data_of(NULL::my_custom_type);
What you need is a well-known type. For every table there is a well-known type automatically. But you can create any type, cast NULL to it and pass it to the function. This way you can build exactly what you have in your question ...
Related answer with a lot more details:
Refactor a PL/pgSQL function to return the output of various SELECT queries