I have an error creating the following function in HSQL:
CREATE FUNCTION getmax ()
RETURNS INT
BEGIN ATOMIC
DECLARE max_event INT;
SET max_event = SELECT MAX(tabla_id) FROM tabla;
RETURN max_event;
END
$$
Error:
5608=42608 wrong or missing data impact clause in declaration
I have looked at the documentation of HSQL and other pages, I invested a great amount of time and I can not solve it.
I need your help please.
I have managed to solve it.
Here is the answer, in case someone else needs it.
CREATE FUNCTION getmax ()
RETURNS INT
READS SQL DATA
RETURN (SELECT MAX(tabla_id) FROM tabla)
$$
Related
I have a problem where my SQL sequence has to be above a certain number to fix a unique constraint error. Now I started to write an if-statement that checks for a certain number and if it's below it should be increased to a certain number. The statement is for Postgres.
I got the separate parts running but the connection over if is throwing an error and I don't know why.
First for selecting the current number:
SELECT nextval('mySequence')
Then to update the number:
SELECT setval('mySequence', targetNumber, true)
The full statement looks something like this in my tries:
IF (SELECT nextval('mySequence') < targetNumber)
THEN (SELECT setval('mySequence', targetNumber, true))
END IF;
and the error is
ERROR: syntax error at »IF«
Can someone explain to me what I did wrong there because the error message isn't giving me much to work with? I would appreciate your help.
Try this:
SELECT setval('mySequence', targetNumber, true)
WHERE (SELECT nextval('mySequence') < targetNumber) is true;
You can use postgres functions if you want to use IF statement.
You can try something like this:
CREATE SEQUENCE seq_test_id_seq;
CREATE TABLE seq_test(
id integer NOT NULL DEFAULT nextval('seq_test_id_seq'),
name VARCHAR
);
CREATE OR REPLACE FUNCTION seq_test_function(target_number bigint)
RETURNS void
LANGUAGE 'plpgsql'
VOLATILE
PARALLEL UNSAFE
COST 100
AS $BODY$
DECLARE
seq_val INTEGER;
BEGIN
SELECT nextval('seq_test_id_seq') INTO seq_val;
RAISE NOTICE 'NEXT SEQUENCE [%]', seq_val;
IF (seq_val < target_number) THEN
SELECT setval('seq_test_id_seq', target_number, true) INTO seq_val;
RAISE NOTICE 'SEQUENCE VALUE MODIFIED [%]', seq_val;
END IF;
END;
$BODY$;
Then call the procedure:
select seq_test_function(10);
I'm working on what shouldn't be too difficult an SQL function: it takes a few parameters to find a specific course in a table, counts how many people are in that course, compares it to the course's maximum capacity, and returns 1 or 0 as appropriate:
drop function if exists room_for_more_students(the_class_name varchar, the_semester_code int);
create function room_for_more_students(the_class_name varchar, the_semester_code int)
returns int as $BODY$
begin
select * from class_offerings as match_table
where class_name = the_class_name and semester_code = the_semester_code;
select count(student_id) from match_table as num_students_in_class;
select avg(maximum_capacity) from match_table as num_students_allowed_in_class;
--These will all be the same so "avg" just means "the maximum capacity for the class"
if num_students_in_class < num_students_allowed_in_class then return 1;
else return 0;
end if;
end
$BODY$
language plpgsql;
This doesn't really seem like it should be all that complex to implement, and the function creates without issue, but every time I try and invoke it through psycopg2 I receive:
ProgrammingError: query has no destination for result data
HINT: If you want to discard the results of a SELECT, use PERFORM instead
I have tried experimenting with PERFORM instead, but any combination I try seems to either keep the same issue or create a host of new ones. I've also done some research on this as there are a few other posts about the same issue, but the majority of the time the answer seems to be that the user hasn't added specific return statements, which I have. I'm completely out of ideas and would appreciate any input possible.
For your case, you must declare some variable and assign it with the result of query. You can not run a query without assign its result to nowhere.
I update your function as below:
drop function if exists room_for_more_students(the_class_name varchar, the_semester_code int);
create function room_for_more_students(the_class_name varchar, the_semester_code int)
returns int as
$BODY$
DECLARE
num_students_allowed_in_class numeric;
num_students_in_class numeric;
begin
WITH match_table AS (
select *
from class_offerings
where class_name = the_class_name and semester_code = the_semester_code
)
select count(student_id), avg(maximum_capacity)
INTO num_students_in_class, num_students_allowed_in_class
from match_table;
if num_students_in_class
Hopefully it match your request!
A novice when it comes to stored procedures/functions. I have searched Google, Stackoverflow, and Youtube and are finding all sorts of examples that are convoluted, some not in English.
I'm trying to understand the basic syntax for a stored function to return a table in Postgresql. In MySql this is elementary but I can't seem to wrap my head around the syntax for Postgresql I have the SQL statement I need to return the rows I want (table), as seen below. I have tried the following code but it doesn't work. Help is much appreciated, thanks in advance.
CREATE OR REPLACE FUNCTION Getcurrent()
RETURNS table AS $schedule$
$BODY$ BEGIN
SELECT *
FROM archived_table
WHERE table_id>=ALL(SELECT table_id FROM archived_table);
RETURN schedule;
END;$BODY$
LANGUAGE plpgsql;
********** Error **********
ERROR: syntax error at or near "AS"
LINE 2: RETURNS table AS $schedule$
^
This is the error message.
I have referenced the following link and have had no luck with this.https://www.postgresql.org/docs/9.1/static/sql-createfunction.html
Im using pgAdminIII, in the public schema, on my company's server.
The desired results is to have the table returned once the function is called.
RETURNS TABLE is not complete, hence the error message.
You can use the RETURNS SETOF <table_name> form, if you intend to return all columns of a table.
Otherwise, you'll need to mention every output column by name and type, with either RETURNS TABLE:
RETURNS TABLE (
col_alias_1 INT,
col_alias_2 TEXT,
col_alias_3 <some_other_type>,
...
)
Or with OUT parameters + RETURNS SETOF RECORD to indicate that you'll (possibly) return multiple rows at once.
Also, if your operation is as simple as a few SQL statements, use LANGUAGE SQL instead:
CREATE OR REPLACE FUNCTION Getcurrent()
RETURNS SETOF archived_table
LANGUAGE SQL
AS $BODY$
SELECT *
FROM archived_table
WHERE table_id>=ALL(SELECT table_id FROM archived_table);
$BODY$;
I am new to SQL, so please try not to be overly critical about my question, I need to create a function which would return me a table (say for example "machine") , which would have a column called "aggtablename" and the rows would be filled with values derived from a database. Here is what i tried and the following error came....so please help me in making my syntax correct, THANKS..
CREATE FUNCTION aggtable() RETURNS TABLE (machineid, serveraggtablename)
AS $table$
BEGIN
RETURN QUERY
SELECT m.machineid, m.serveraggtablename
FROM machine m
END;
$table$
LANGUAGE plpgsql;
select aggtable();
ERROR: function aggtable() does not exist LINE 1: select aggtable();
^ HINT: No function matches the given name and argument types. You might need to add explicit type casts.
The arguments of the table you're returning do not have any type.
try adding a type such as machineid int.
check this post
How can a Postgres Stored Function return a table
Try this
CREATE TYPE machineType as (machineid int, serveraggtable character varying);
CREATE FUNCTION aggtable() RETURNS SETOF machineType AS
'SELECT m.machineid, m.serveraggtablename FROM machine m;'
LANGUAGE 'sql';
SELECT * FROM aggtable();
https://wiki.postgresql.org/wiki/Return_more_than_one_row_of_data_from_PL/pgSQL_functions
I am relatively new to postgresql and battling my way to get familiarized with it. I had run in to an error while writing a new pl/sql function. ERROR: type "ordered_parts" does not exist
CREATE OR REPLACE FUNCTION get_ordered_parts(var_bill_to integer)
RETURNS SETOF ordered_parts AS
$BODY$
declare
var_ordered_id record;
var_part ordered_parts;
begin
for var_ordered in select order_id from view_orders where bill_to = var_bill_to
loop
for var_part select os.po_num,os.received,os.customer_note,orders.part_num,orders.description,orders.order_id,orders.remaining_quantity from (select vli.part_num,vli.description,vli.order_id,vli.quantity - vli.quantity_shipped as remaining_quantity from view_line_items as vli where vli.order_id in (select order_id from view_orders where bill_to = var_bill_to and order_id = var_ordered.order_id) and vli.quantity - vli.quantity_shipped > 0)as orders left join order_sales as os on orders.order_id = os.order_id
then
-- Then we've found a leaf part
return next var_part;
end if;
end loop;
end;
$BODY$
LANGUAGE 'plpgsql' VOLATILE
COST 100
ROWS 1000;
ALTER FUNCTION get_ordered_parts(integer) OWNER TO postgres;
just note - your code is perfect example how don't write stored procedure ever. For some longer results it can be extremely slow. Minimally two cycles can be joined to one, or better, you can use just only one RETURN QUERY statement. Next issue is zero formatting of embedded SQL - good length of line is between 70 and 100 chars - writing long SQL statement to one line going to zero readability and maintainability code.
Relation database is not array, and any query has some cost, so don't use nested FOR if you really don't need it. I am sorry for offtopic.
The error message is telling you that you have declared the return type of your function to be SETOF ordered_parts, but it doesn't know what kind of thing ordered_parts is. Within your Declare block you also have a variable declared as this same type (var_part ordered_parts).
If you had a table or view called ordered_parts, then its "row type" would be automatically created as a type, but this is not the case here. if you just want to use an arbitrary row from a result set, you can just use the generic type record.
So in this case your function should say RETURNS SETOF record, and your Declare block var_part record.
Bonus tip: rather than looping over the result of your query and running RETURN NEXT on each row, you can use RETURN QUERY to throw the whole result set into the returned set in one go. See this Postgres manual page.