remove output pharentesis in a function - postgresql

I'm trying to run this function and all records in the output have a parenthesis, how can I get rid of them?
the below function simply outputs the records in the loop for debugging, I just want to remove the pharentesis.
CREATE OR REPLACE FUNCTION public.loop_test(_report_id integer)
RETURNS void
LANGUAGE plpgsql
AS $function$
declare
_rid RECORD ;
BEGIN
FOR _rid IN
SELECT id FROM schema.table where id=_report_id
loop
raise notice '%',_rid;
END LOOP;
END
$function$
;
This is what I get (sample)
(1755)
(1789)
(1757)
(649)
(1781)
I need just the numbers..
Let me clarify that I would like to use the _rid variable on an insert within this function but until I don't get rid of the pharentesis I can't move on.

Related

How to use FOREACH in a PostgreSQL LOOP

I am trying to write a very simple pgsql statement to loop through a simple array of state abbreviations.
CREATE OR REPLACE FUNCTION my_schema.showState()
RETURNS text AS
$$
DECLARE
my_array text[] := '["az","al", "ak", "ar"]'
BEGIN
FOREACH state IN my_array
LOOP
RETURN SELECT format('%s', state);
END LOOP;
END;
$$ LANGUAGE plpgsql;
SELECT * FROM showState();
I am using PostgresSQL version 11+. I keep getting an error ERROR: syntax error at or near "BEGIN" The output I want to see here is just seeing the state abbreviation printed in the results window for now. Like this:
What am I doing wrong here?
There's a ; missing after my_array text[] := '["az","al", "ak", "ar"]'.
'["az","al", "ak", "ar"]' isn't a valid array literal.
If you want a set returning function, you need to declare its return type as a SETOF.
The ARRAY keyword is missing in the FOREACH's head.
state must be declared.
You need to use RETURN NEXT ... to push a value into the set to be returned.
format() is pointless here, it doesn't effectively do anything.
With all that rectified one'd get something along the lines of:
CREATE
OR REPLACE FUNCTION showstate()
RETURNS SETOF text
AS
$$
DECLARE
my_array text[] := ARRAY['az',
'al',
'ak',
'ar'];
state text;
BEGIN
FOREACH state IN ARRAY my_array
LOOP
RETURN NEXT state;
END LOOP;
END;
$$
LANGUAGE plpgsql;
db<>fiddle

Declaring the table name in constant in Postgres Stored procedure

I have a sample stored procedure where in I have to use a table for multiple operations. I want to declare the table name as a constant and then re-use it wherever required. Below is the sample code which i wrote:
CREATE OR REPLACE FUNCTION get_data()
RETURNS void AS
$func$
DECLARE
table_name_a CONSTANT TEXT = asp.monitoring_bookmark_original;
cursor_file CURSOR FOR
select distinct filename,systemuid from table_name_a;
cursor_data CURSOR FOR
select * from table_name_a where filename = v_filename and systemuid=v_systemuid order by mindatetime, maxdatetime;
BEGIN
--open the file cursor
//logic goes here
END;
$func$
LANGUAGE plpgsql;
When I try to run this procedure I am getting error:
ERROR: missing FROM-clause entry for table "asp"
LINE 1: SELECT asp.monitoring_bookmark_original
What is wrong in this code? How do I correct this?
Well you can use dynamic SQL, but realize dynamic SQL often adds way more complexity. Good when really needed but should be avoided when possible. The following shows what would be needed for what you want to do. Is not having to type the table name for each SQL statement worth the additional trouble?
create or replace function get_data()
returns void as
$func$
declare
table_name_a constant text = 'asp.monitoring_bookmark_original';
file_cursor text = 'select distinct filename,systemuid from %i';
file_ref refcursor;
file_rec record;
data_cursor text =$stmt$select * from %i where filename = '%s' and systemuid= '%s' order by mindatetime, maxdatetime$stmt$;
data_ref refcursor;
data_rec record;
begin
--open the file cursor
open file_ref for execute format(file_cursor,table_name_a);
loop
fetch next from file_ref into file_rec;
exit when not found;
-- and extending from what the second query inplies
open data_ref for execute format(data_cursor,table_name_a,file_rec.filename,file_rec.systemid);
loop
fetch next from data_ref into data_rec;
exit when not found;
--//logic goes here
end loop;
end loop ;
end;
$func$
language plpgsql;

Create a function to get column from multiple tables in PostgreSQL

I'm trying to create a function to get a field value from multiple tables in my database. I made script like this:
CREATE OR REPLACE FUNCTION get_all_changes() RETURNS SETOF RECORD AS
$$
DECLARE
tblname VARCHAR;
tblrow RECORD;
row RECORD;
BEGIN
FOR tblrow IN SELECT tablename FROM pg_catalog.pg_tables WHERE schemaname='public' LOOP /*FOREACH tblname IN ARRAY $1 LOOP*/
RAISE NOTICE 'r: %', tblrow.tablename;
FOR row IN SELECT MAX("lastUpdate") FROM tblrow.tablename LOOP
RETURN NEXT row;
END LOOP;
END LOOP;
END
$$
LANGUAGE 'plpgsql' ;
SELECT get_all_changes();
But it is not working, everytime it shows this error
tblrow.tablename" not defined in line "FOR row IN SELECT MAX("lastUpdate") FROM tblrow.tablename LOOP"
Your inner FOR loop must use the FOR...EXECUTE syntax as shown in the manual:
FOR target IN EXECUTE text_expression [ USING expression [, ... ] ] LOOP
statements
END LOOP [ label ];
In your case something along this line:
FOR row IN EXECUTE 'SELECT MAX("lastUpdate") FROM ' || quote_ident(tblrow.tablename) LOOP
RETURN NEXT row;
END LOOP
The reason for this is explained in the manual somewhere else:
Oftentimes you will want to generate dynamic commands inside your PL/pgSQL functions, that is, commands that will involve different tables or different data types each time they are executed. PL/pgSQL's normal attempts to cache plans for commands (as discussed in Section 39.10.2) will not work in such scenarios. To handle this sort of problem, the EXECUTE statement is provided[...]
Answer to your new question (mislabeled as answer):
This can be much simpler. You do not need to create a table just do define a record type.
If at all, you would better create a type with CREATE TYPE, but that's only efficient if you need the type in multiple places. For just a single function, you can use RETURNS TABLE instead :
CREATE OR REPLACE FUNCTION get_all_changes(text[])
RETURNS TABLE (tablename text
,"lastUpdate" timestamp with time zone
,nums integer) AS
$func$
DECLARE
tblname text;
BEGIN
FOREACH tblname IN ARRAY $1 LOOP
RETURN QUERY EXECUTE format(
$f$SELECT '%I', MAX("lastUpdate"), COUNT(*)::int FROM %1$I
$f$, tblname)
END LOOP;
END
$func$ LANGUAGE plpgsql;
A couple more points:
Use RETURN QUERY EXECUTE instead of the nested loop. Much simpler and faster.
Column aliases would only serve as documentation, those names are discarded in favor of the names declared in the RETURNS clause (directly or indirectly).
Use format() with %I to replace the concatenation with quote_ident() and %1$I to refer to the same parameter another time.
count() usually returns type bigint. Cast the integer, since you defined the column in the return type as such: count(*)::int.
Thanks,
I finally made my script like:
CREATE TABLE IF NOT EXISTS __rsdb_changes (tablename text,"lastUpdate" timestamp with time zone, nums bigint);
CREATE OR REPLACE FUNCTION get_all_changes(varchar[]) RETURNS SETOF __rsdb_changes AS /*TABLE (tablename varchar(40),"lastUpdate" timestamp with time zone, nums integer)*/
$$
DECLARE
tblname VARCHAR;
tblrow RECORD;
row RECORD;
BEGIN
FOREACH tblname IN ARRAY $1 LOOP
/*RAISE NOTICE 'r: %', tblrow.tablename;*/
FOR row IN EXECUTE 'SELECT CONCAT('''|| quote_ident(tblname) ||''') AS tablename, MAX("lastUpdate") AS "lastUpdate",COUNT(*) AS nums FROM ' || quote_ident(tblname) LOOP
/*RAISE NOTICE 'row.tablename: %',row.tablename;*/
/*RAISE NOTICE 'row.lastUpdate: %',row."lastUpdate";*/
/*RAISE NOTICE 'row.nums: %',row.nums;*/
RETURN NEXT row;
END LOOP;
END LOOP;
RETURN;
END
$$
LANGUAGE 'plpgsql' ;
Well, it works. But it seems I can only create a table to define the return structure instead of just RETURNS SETOF RECORD. Am I right?
Thanks again.

Iterate over table returned by function

I've declared two functions (duplicate_iofs & duplicate_ioftypes) that both return a table after performing INSERT operations :
CREATE OR REPLACE FUNCTION duplicate_iofs(IN iof_group_src_id integer, IN iof_group_dst_id integer)
RETURNS TABLE(src_id integer, new_id integer) AS $$
BEGIN
-- DO INSERT REQUESTS
END;
CREATE OR REPLACE FUNCTION duplicate_ioftypes(IN iof_group_src_id integer, IN iof_group_dst_id integer)
RETURNS TABLE(src_id integer, new_id integer) AS $$
BEGIN
-- DO INSERT REQUESTS
END;
How can I do something similar like that in a third function :
-- 1. Call duplicate_iofs(...) and store the result table (e.g. iofs_table)
-- 2. Call duplicate_ioftypes(...) and store the result table (e.g. ioftypes_table).
-- 3. Iterate through 'iofs_table' and 'ioftypes_table' with nested loops :
FOR iof_row IN SELECT * FROM iofs_table LOOP
FOR ioftype_row IN SELECT * FROM ioftypes_table LOOP
-- DO SOMETHING
END LOOP;
END LOOP;
Note : duplicate_iofs() and duplicate_ioftypes() MUST be called only once and thus, MUST NOT be called into the nested loop.
You can try something like this:
DECLARE
curs_iof CURSOR FOR SELECT * FROM iofs_table;
curs_ioftype CURSOR FOR SELECT * FROM ioftypes_table;
BEGIN
OPEN SCROLL curs_iof;
OPEN SCROLL curs_ioftype;
FETCH curs_iof INTO iof_row;
WHILE FOUND LOOP
FETCH FIRST FROM curs_ioftype INTO ioftype_row;
WHILE FOUND LOOP
-- DO SOMETHING
FETCH curs_ioftype INTO ioftype_row;
END LOOP;
FETCH curs_iof INTO iof_row;
END LOOP;
CLOSE curs_iof;
CLOSE curs_ioftype;
END;
Details here.

I want to have my pl/pgsql script output to the screen

I have the following script that I want output to the screen from.
CREATE OR REPLACE FUNCTION randomnametest() RETURNS integer AS $$
DECLARE
rec RECORD;
BEGIN
FOR rec IN SELECT * FROM my_table LOOP
SELECT levenshtein('mystring',lower('rec.Name')) ORDER BY levenshtein;
END LOOP;
RETURN 1;
END;
$$ LANGUAGE plpgsql;
I want to get the output of the levenshein() function in a table along with the rec.Name. How would I do that? Also, it is giving me an error about the line where I call levenshtein(), saying that I should use perform instead.
Assuming that you want to insert the function's return value and the rec.name into a different table. Here is what you can do (create the table new_tab first)-
SELECT levenshtein('mystring',lower(rec.Name)) AS L_val;
INSERT INTO new_tab (L_val, rec.name);
The usage above is demonstrated below.
I guess, you can use RAISE INFO 'This is %', rec.name; to view the values.
CREATE OR REPLACE FUNCTION randomnametest() RETURNS integer AS $$
DECLARE
rec RECORD;
BEGIN
FOR rec IN SELECT * FROM my_table LOOP
SELECT levenshtein('mystring',lower(rec.Name))
AS L_val;
RAISE INFO '% - %', L_val, rec.name;
END LOOP;
RETURN 1;
END;
$$ LANGUAGE plpgsql;
Note- the FROM clause is optional in case you select from a function in a select like netxval(sequence_name) and don't have any actual table to select from i.e. like SELECT nextval(sequence_name) AS next_value;, in Oracle terms it would be SELECT sequence_name.nextval FROM dual; or SELECT function() FROM dual;. There is no dual in postgreSQL.
I also think that the ORDER BY is not necessary since my assumption would be that your function levenshtein() will most likely return only one value at any point of time, and hence wouldn't have enough data to ORDER.
If you want the output from a plpgsql function like the title says:
CREATE OR REPLACE FUNCTION randomnametest(_mystring text)
RETURNS TABLE (l_dist int, name text) AS
$BODY$
BEGIN
RETURN QUERY
SELECT levenshtein(_mystring, lower(t.name)), t.name
FROM my_table t
ORDER BY 1;
END;
$$ LANGUAGE plpgsql;
Declare the table with RETURNS TABLE.
Use RETURN QUERY to return records from the function.
Avoid naming conflicts between column names and OUT parameters (from the RETURNS TABLE clause) by table-qualifying column names in queries. OUT parameters are visible everywhere in the function body.
I made the string to compare to a parameter to the function to make this more useful.
There are other ways, but this is the most effective for the task. You need PostgreSQL 8.4 or later.
For a one-time use I would consider to just use a plain query (= function body without the RETURN QUERY above).