I made a function in pgadmin
create or replace function get_source2(a text)
returns integer as
$$
declare
a text;
geom geometry;
begin
select get_source(geom)
from a;
end;
$$
language plpgsql;
I want input a by table name How can I do? I try to like this
select get_source2('postgis.center')
but I get:
ERROR: relation "a" does not exist LINE 2: from a help me
try this:
create or replace function get_source2(a text)
returns integer as
$$
declare
geom geometry;
begin
execute 'select get_source(geom) from '||quote_ident(a) into geom;
return geom;
end;
$$
language plpgsql;
Related
I have a simple Postgres function where I want to take table_name as a parameter and pass it into an argument and delete the data from table by condition.
CREATE OR REPLACE FUNCTION cdc.audit_refresh(tablename text)
RETURNS integer AS
$$
BEGIN
delete from tablename where id<4;
RETURN(select 1);
END;
$$ LANGUAGE plpgsql;
select cdc.audit_refresh('cdc.adf_test');
But it throws out an error that tablename
ERROR: relation "tablename" does not exist in the delete statement.(refer snapshot)
What you want to achieve is to execute Dynamic SQL statements. You can do this with EXECUTE. See more here
CREATE OR REPLACE FUNCTION audit_refresh(tablename text)
RETURNS integer AS
$$
DECLARE
stmt TEXT;
BEGIN
stmt = 'delete from '||tablename||' where id<4;';
EXECUTE stmt;
RETURN 1;
END
$$ LANGUAGE plpgsql;
May I ask on how to call a method when the content of the stored procedure is about select statement? (Using postgreSQL)
CREATE OR REPLACE PROCEDURE select_table(table_name VARCHAR(255))
language plpgsql
as $$
BEGIN
EXECUTE('SELECT * FROM' || ' ' || quote_ident(table_name));
END $$;
CALL select_table('employee_table');
EDITED(USING FUNCTION)
CREATE OR REPLACE FUNCTION select_table(table_name VARCHAR(255))
language plpgsql
as $$
BEGIN
SELECT * FROM table_name
RETURN table_name;
END $$;
In PostgreSQL procedures doesn't execute any select statements and doesn't have return.
For returning data you can use functions. But functions also cannot return different structural data, examples:
CREATE OR REPLACE FUNCTION fr_test()
RETURNS TABLE(id integer, bookname character varying)
LANGUAGE plpgsql
AS $function$
begin
return QUERY
SELECT tb.id, tb.bookname from rbac.books tb;
end;
$function$
;
or
CREATE OR REPLACE FUNCTION fr_test()
RETURNS setof public.books
LANGUAGE plpgsql
AS $function$
begin
return QUERY
SELECT * from public.books;
end;
$function$
;
But for returning difference tables you can do it using procedures and using out refcursor, like as in Oracle. For example:
create or replace procedure pr_test(OUT r1 refcursor)
as $$
begin
open r1 for
select * from public.books;
end;
$$ language plpgsql;
The following code currently works on PostgreSQL 13.3 (via Supabase.io). Both functions get_owned_base_ids and get_bases_editable have return type of setof bigint:
CREATE FUNCTION get_owned_base_ids()
returns setof bigint
stable
language sql
as $$
select id
from bases
where bases.owner_user_id = auth.uid();
$$;
-- CREATE FUNCTION get_bases_editable()
-- returns setof bigint
-- ... similar to get_owned_base_ids()
-- $$;
CREATE FUNCTION xyz (base_id bigint)
returns int
language plpgsql
as $$
BEGIN
IF base_id not in (select get_owned_base_ids() UNION select get_bases_editable()) THEN
-- note: actual function logic is simplified for this question
return 1;
END IF;
return 0;
END;
$$;
Is it possible to define a setof bigint and assign that from the select union? Something like this:
CREATE FUNCTION xyz (base_id bigint)
returns int
language plpgsql
as $$
DECLARE
allowed_base_ids bigint; -- needs to be a setof
BEGIN
select into allowed_base_ids get_owned_base_ids() UNION select get_bases_editable();
IF kv.base_id not in allowed_base_ids THEN
-- note: actual function logic is simplified for this question
return 1;
END IF;
return 0;
END;
$$;
It usually does not make much sense and use much memory of the result set is large, but you can use an array:
DECLARE
allowed_base_ids bigint[];
BEGIN
allowed_base_ids := array(SELECT * FROM get_owned_base_ids()
UNION ALL
SELECT * FROM get_bases_editable());
IF kv.base_id <> ALL (allowed_base_ids) THEN
...
END IF;
END;
Why does accessing a value of the RECORD argument like this works:
CREATE OR REPLACE FUNCTION TT_GetVal1(a RECORD)
RETURNS text AS $$
DECLARE
BEGIN
RETURN a.val1::text;
END;
$$ LANGUAGE plpgsql VOLATILE;
SELECT TT_GetVal1(foo.*)
FROM (SELECT 1 id, 'a' val1) foo;
But not like this:
CREATE OR REPLACE FUNCTION TT_GetVal2(a RECORD)
RETURNS text AS $$
DECLARE
query text;
result text;
BEGIN
query = 'SELECT ($1).val1::text';
EXECUTE query INTO result USING a;
RETURN result;
END;
$$ LANGUAGE plpgsql VOLATILE;
SELECT TT_GetVal2(foo.*)
FROM (SELECT 1 id, 'a' val1) foo;
which returns:
ERROR: could not identify column "val1" in record data type
LINE 1: SELECT ($1).val1::text
How can I dynamically access RECORD values?
The RECORD only lives inside the plpgsql scope. The values are passed to the execute but not the column names.
You can - if the record is from a table - do something like this:
create table table1 (
id integer,
val1 text
);
CREATE OR REPLACE FUNCTION TT_GetVal2(a RECORD)
RETURNS text AS $$
DECLARE
query text;
result text;
BEGIN
query = 'SELECT ($1::text::table1).val1';
EXECUTE query INTO result USING a;
RETURN result;
END;
$$ LANGUAGE plpgsql VOLATILE;
SELECT TT_GetVal2(foo)
FROM (SELECT 1 id, 'a' val1) foo;
Best regards,
Bjarni
I've a PostgreSQL function that returns a string. I want to use this function into another one but I obtain an error.
These are the sample functions, with get_some_string that returns text, and use_the_string where I want to call the previous one and store the result in a variable:
CREATE OR REPLACE FUNCTION public.get_some_string()
RETURNS text AS
$func$
DECLARE
BEGIN
return 'mystring';
END
$func$ LANGUAGE plpgsql VOLATILE;
CREATE OR REPLACE FUNCTION public.use_the_string()
RETURNS boolean AS
$func$
DECLARE
mytext text;
BEGIN
mytext := select public.get_some_string();
END
$func$ LANGUAGE plpgsql VOLATILE;
If I run this query I obtain the error:
ERROR: syntax error at or near "select"
LINE 24: mytext := select public.get_some_string();
What I'm doing wrong? How can I use the return value of the first function into the second one?
You don't need a select:
CREATE OR REPLACE FUNCTION public.use_the_string()
RETURNS boolean AS
$func$
DECLARE
mytext text;
BEGIN
mytext := public.get_some_string();
END
$func$ LANGUAGE plpgsql VOLATILE;
The second one must be:
RETURNS boolean AS
$func$
DECLARE
mytext text;
BEGIN
select public.get_some_string() into mytext;
END
$func$ LANGUAGE plpgsql VOLATILE;
or
mytext := (select public.get_some_string());
or
mytext := public.get_some_string();
Note to other answers: select is implicitly added in plpgsql context. Example:
do $$
declare
v text[];
begin
v := array_agg(datname) from pg_database;
raise info 'List of databases: %', v;
end $$;
So when you call mytext := select public.get_some_string(); it is transformed to select select public.get_some_string(); internally.
Thats why parenthesesis mytext := (select public.get_some_string()); could be the solution: select (select public.get_some_string()); is the acceptable statement.