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
Related
This request:
unnest('{1,2}'::int[]);
gives to me this error:
syntax error at or near "unnest"
neither unnest('{1,2}'); works
Why?
intire:
CREATE OR REPLACE FUNCTION result() RETURNS setof users AS
$$
DECLARE
BEGIN
unnest('{1,2}'::int[]);
RETURN QUERY SELECT * FROM users;
END;
$$ LANGUAGE plpgsql;
SELECT result();
EDIT
The core idea:
To retrive and manipualate with the bigint[] which is stored inside in a column.
So, i have got this:
SELECT * FROM users WHERE email = email_ LIMIT 1 INTO usr;
Then, usr.chain contains some bigint[] data. For example, {1,2,3,4,5,6,7,8,9,10}. I want to save only the 4 last of them.
How to retrieve {7,8,9,10} and {1,2,3,4,5,6} and iterate over these arrays?
I only found the solution is to use SELECT FROM unnest(usr.chain) AS x ORDER BY x ASC LIMIT (sdl - mdl) OFFSET mchain and so on. but unnest function gives to me this stupid error. I'm really do not understand why it happends. It doesn't work in sucj easy case I wrote at the beginning of the question. subarray function doesn't work because of the data type is bigint[] not int[]
Futher more, the code unnest(ARRAY[1,2]) gives to me the same error.
http://www.postgresql.org/docs/9.2/static/functions-array.html
The same error for array_append function
to iterate over array:
CREATE OR REPLACE FUNCTION someresult(somearr bigint[] ) RETURNS setof bigint AS
$$
DECLARE
i integer;
x bigint;
BEGIN
for x in select unnest($1)
loop
-- do something
return next x;
end loop;
-- or
FOR i IN array_lower($1, 1) .. array_upper($1, 1)
LOOP
-- do something like:
return next ($1)[i];
end loop;
END;
$$ LANGUAGE plpgsql;
select someresult('{1,2,3,4}') ;
array_append ....
CREATE OR REPLACE FUNCTION someresult2(somearr bigint[],val bigint ) RETURNS bigint[] AS
$$
DECLARE
somenew_arr bigint[];
BEGIN
somenew_arr = array_append($1, $2 );
return somenew_arr;
END;
$$ LANGUAGE plpgsql;
select someresult2('{1,2,3,4}' ,222) ;
so, here you have basic example how to iterate and append arrays. Now can you write step by step what you want to do, to achieve .
I am trying to create a PostgreSQL function which will update a list of rows. So I want to take a list of text[] as an argument and use the IN clause to execute the query. Also, i want to get the number of rows updated as a returned value.
This worked for me:
CREATE FUNCTION set_mail_isbeingused(list_of_mail_names text[]) RETURNS void AS $$
BEGIN
FOR i in 1 .. array_upper(list_of_mail_names,1)
LOOP
UPDATE mail_isbeingused set isbeingused = 'true' where mailname = list_of_mail_names[i];
END LOOP;
END;
$$
LANGUAGE plpgsql;
But i want to execute it in one update query with IN clause.
CREATE FUNCTION set_mail_isbeingused(list_of_mail_names text[]) RETURNS void AS $$
BEGIN
UPDATE mail_isbeingused set isbeingused = 'true' where mailname in list_of_mail_names;
END;
$$
LANGUAGE plpgsql;
This is what I have been trying to do. Can somebody help me in fixing this?
You need to use the ANY operator with an array. You can't use IN
To obtain the number of rows update, use GET DIAGNOSTICS
CREATE FUNCTION set_mail_isbeingused(list_of_mail_names text[])
RETURNS integer --<< you need to change the return type
AS $$
DECLARE
l_rows integer;
BEGIN
UPDATE mail_isbeingused
set isbeingused = true
where mailname = ANY (list_of_mail_names);
GET DIAGNOSTICS l_rows = ROW_COUNT; --<< get the number of affected rows
RETURN l_rows;
END;
$$
LANGUAGE plpgsql;
Boolean constants don't need to be put into single quotes true is a boolean value 'true' is a string constant.
I am call the function but it is returning error that array value must start with "{" or dimension information using
Create or Replace Function get_post_process_info(IN v_esdt_pp character varying[])
Returns setof Record as
$$
Declare
post_processes RECORD;
esdt_value character varying;
v_sdsname character varying[];
v_dimension character varying[];
counter int := 1;
Begin
-- to loop through the array and get the values for the esdt_values
FOR esdt_value IN select * from unnest(v_esdt_pp)
LOOP
-- esdt_values as a key for the multi-dimensional arrays and also as the where clause value
SELECT distinct on ("SdsName") "SdsName" into v_sdsname from "Collection_ESDT_SDS_Def" where "ESDT" = esdt_values;
raise notice'esdt_value: %',esdt_value;
END LOOP;
Return ;
End
$$ Language plpgsql;
Select get_post_process_info(array['ab','bc]);
Your function sanitized:
CREATE OR REPLACE FUNCTION get_post_process_info(v_esdt_pp text[])
RETURNS SETOF record AS
$func$
DECLARE
esdt_value text;
v_sdsname text[];
v_dimension text[];
counter int := 1;
BEGIN
FOR esdt_value IN
SELECT * FROM unnest(v_esdt_pp) t
LOOP
SELECT distinct "SdsName" INTO v_sdsname
FROM "Collection_ESDT_SDS_Def"
WHERE "ESDT" = esdt_value;
RAISE NOTICE 'esdt_value: %', esdt_value;
END LOOP;
END
$func$ Language plpgsql;
Call:
Select get_post_process_info('{ab,bc}'::text[]);
DISTINCT instead of DISTINCT ON, missing table alias, formatting, some cruft, ...
Finally the immediate cause of the error: a missing quote in the call.
The whole shebang can possibly be replaced with a single SQL statement.
But, obviously, your function is incomplete. Nothing is returned yet. Information is missing.
I've got a pretty simple function defined like so:
CREATE OR REPLACE FUNCTION create_new_order(....) RETURNS integer AS
$BODY$
BEGIN
PERFORM add_points_to_usage(client_id_p, date_in_p, total_points_p);
INSERT INTO orders (...) VALUES (...)
RETURNING ident;
END;
$BODY$ LANGUAGE plpgsql;
Where I'm struggling is how to actually RETURN the value stored in the ident field back via the RETURNING clause. I've tried setting the value to a variable but that either doesn't work or I'm just messing up the syntax.
You're missing the variable declaration, the INTO clause and the final RETURN:
CREATE OR REPLACE FUNCTION create_new_order(....) RETURNS integer AS
$BODY$
DECLARE
var_ident int;
BEGIN
PERFORM add_points_to_usage(client_id_p, date_in_p, total_points_p);
INSERT INTO orders (...) VALUES (...)
RETURNING ident INTO var_ident;
RETURN var_ident;
END;
$BODY$ LANGUAGE plpgsql;
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.