I keep getting the "SELECT query has no destination for result data" error upon calling this test procedure. What am I doing wrong? I did try adding the RETURN() command prior to SELECT statement but that didn't work either.
CREATE OR REPLACE PROCEDURE SchemaName.SP_Testing_Creating_Procedure (OUT ColumnName VARCHAR(9))
AS $$
BEGIN
SELECT TOP 10 ColumnName FROM SchemaName.TableName where ColumnName is not null;
END;
$$
LANGUAGE plpgsql;
CALL SchemaName.SP_Testing_Creating_Procedure();
As John mentioned you need to put the result into OUT column, examples of using IN, OUT and INOUT parameters you can find here
But if you need to return a few rows as a result, you have to use refcursor
as it's described here
CREATE OR REPLACE PROCEDURE SchemaName.SP_Testing_Creating_Procedure (INOUT result refcursor)
AS $$
BEGIN
OPEN result FOR
SELECT TOP 10 ColumnName
FROM SchemaName.TableName
WHERE ColumnName IS NOT null;
END;
$$
LANGUAGE plpgsql;
Then you can call the stored procedure in a transaction
BEGIN;
CALL logs.SP_Testing_Creating_Procedure('mycursor');
FETCH ALL FROM mycursor;
COMMIT;
another option is temp table which is also described in the above doc
Your procedure is running a SELECT command, but it is not doing anything with the results.
If your intention was to return a result set, you will need to put data in the OUT column.
See: Returning a result set - Amazon Redshift
Related
I have a function my_funct(param1,param2) returning a SELECT QUERY as a text, I usually C/c the result, remove quotes, then run it.
How can execute the returned text in a query that call the function ?
I expect something like this:
SELECT resultOf( myfunct('foo','bar'))
with no extra columnname/type to declare. If such function does not exits built-in, let's create it, I don't mind.
If I understood correctly you want
Call a function returning a select query as text
Run that query to get the result.
Number and type of columns are dynamic
1. Using Do Block:
DO
$$
declare
ref_cursor refcursor:='mycursor';
begin
open ref_cursor for execute (select * from my_funct('foo','bar')) ;
end;
$$;
--Fetch all data from cursor
Fetch all from mycursor;
2. Using Function returning refcursor:
You can create a function like below:
create function my_funct1(param1 text) returns refcursor as
$$
declare
ref_cursor refcursor:='mycursor';
begin
open ref_cursor for execute param1;
return ref_cursor;
end;
$$
language plpgsql
To call above function use following code:
begin ;
select my_funct1((select * from my_funct('foo','bar')) );
fetch all from mycursor;
commit;
DEMO
How is it possible to send a query to all databases on a server? I do not want to input all databases names, the script should auto-detect them.
example query:
SELECT SUM(tourney_results.amt_won)-SUM((tourney_summary.amt_buyin+tourney_summary.amt_fee)) as results
FROM tourney_results
INNER JOIN tourney_summary
ON tourney_results.id_tourney=tourney_summary.id_tourney
Where id_player=(SELECT id_player FROM player WHERE player_name='Apple');
So what I want to achieve here, if there is 2 databases, the first one would result 60, the second one would result 50, I need the 55 output here.
All databeses would have the same structure, tables etc.
You can do it using plpgsql and db_link. First install the db_link extension in the database you are connecting to:
CREATE EXTENSION dblink;
Then use a plpgsql function which iterates over all database on the server and executes the query. See this example (see comments inline). Note that I used a sample query in the function. You have to adapt the function with your real query:
CREATE or REPLACE FUNCTION test_dblink() RETURNS BIGINT AS
$$
DECLARE pg_database_row record;
query_result BIGINT;
_dbname TEXT;
_conn_name TEXT;
return_value BIGINT;
BEGIN
--initialize the final value
return_value = 0;
--first iterate over the records in the meta table pg_database
FOR pg_database_row in SELECT * FROM pg_database WHERE (NOT datistemplate) AND (datallowconn) LOOP
_dbname = pg_database_row.datname;
--build a connection name for db_link
_conn_name=_dbname||'myconn';
--close the connection is already active:
IF array_contains(dblink_get_connections(),_conn_name) THEN
PERFORM dblink_disconnect(_conn_name);
END IF;
-- open the connection with the actual database name
PERFORM dblink_connect(_dbname||'myconn', 'dbname='||_dbname);
-- check if the table does exist in the database:
PERFORM * FROM dblink(_conn_name,'SELECT 1 from pg_tables where tablename = ''your_table''') AS t(id int) ;
IF FOUND THEN
-- if the table exist, perform the query and save the result in a variable
SELECT * FROM dblink(_conn_name,'SELECT sum(id) FROM your_table limit 1') AS t(total int) INTO query_result;
IF query_result IS NOT NULL THEN
return_value = return_value + query_result;
END IF;
END IF;
PERFORM dblink_disconnect(_conn_name);
END LOOP;
RETURN return_value;
END;
$$
LANGUAGE 'plpgsql';
Execute the function with
select test_dblink();
I have a postgresql function
CREATE OR REPLACE FUNCTION fixMissingFiles() RETURNS VOID AS $$
DECLARE
deletedContactId integer;
BEGIN
SELECT INTO deletedContactId contact_id FROM myContacts WHERE id=206351;
-- print the value of deletedContactId variable to the console
END;
$$ LANGUAGE plpgsql;
How can I print the value of the deletedContactId to the console?
You can raise a notice in Postgres as follows:
RAISE NOTICE 'Value: %', deletedContactId;
Read here for more details.
Also, the SELECT INTO you're using looks like PostgreSQL for copying rows into a table. See, for example, the SELECT INTO doc page which state: "SELECT INTO -- define a new table from the results of a query"
In pgplSQL I'm used to seeing it in this order: SELECT INTO ... so your first line should probably be:
SELECT contact_id INTO deletedContactId FROM myContacts WHERE id=206351;
As described in Executing a Query with a Single-Row Result.
If I write a simple function doSomething, I can get its result by executing :
select doSomething() from dual;
But, if I wish to call a procedure that has an OUT cursor being passed to it (along with another int parameter), how do I call that procedure inside a query and access the result of the cursor ?
Calling it inside a query is not compulsory.. its just that I want to access the results of that procedure
You can create a procedure like
CREATE OR REPLACE PROCEDURE your_procedure(out_cursor OUT sys_refcursor)
IS
BEGIN
OPEN out_cursor FOR
SELECT employee_name
FROM employees;
END;
/
Once you create your procedure wrap the procedure in a function which returns a cursor like the following
CREATE OR REPLACE FUNCTION your_function
RETURN sys_refcursor
AS
o_param sys_refcursor;
BEGIN
o_param := NULL;
your_procedure(o_param);
RETURN o_param;
EXCEPTION
WHEN NO_DATA_FOUND
THEN
-- raise
WHEN OTHERS
THEN
-- raise
END your_function;
/
To see the results from sql do as
select your_function from dual;
Update 1
To see result in SQL Developer
Step 1
Double click on your results in SQL Developer
[Results][1]
Step 2 Single Click on the button with dots. That will pop up the values
[Grid][2]
You can Do Something Like This
select doSomething(cursor (select int_col from your_table)) colname from dual
Hope this Help
I am using Postgresql 8.3 and have the following simple function that will return a refcursor to the client
CREATE OR REPLACE FUNCTION function_1() RETURNS refcursor AS $$
DECLARE
ref_cursor REFCURSOR;
BEGIN
OPEN ref_cursor FOR SELECT * FROM some_table;
RETURN (ref_cursor);
END;
$$ LANGUAGE plpgsql;
Now , I can use the following SQL commands to call this function and manipulate the returned cursor ,but the cursor name is automatically generated by the PostgreSQL
BEGIN;
SELECT function_1(); --It will output the generated cursor name , for example , "<unnamed portal 11>" ;
FETCH 4 from "<unnamed portal 11>";
COMMIT;
Besides explicitly declaring the cursor name as the input parameter of the function as described by 38.7.3.5. Returning Cursors, can I declare my own cursor name and use this cursor name to manipulate the returned cursor instead of Postgresql automatically generates for me ?
If not, are there any commands that can get the generated cursor name ?
I'm not quite sure from wich version of Postgre this is available (in 8.4 it is valid) but i found quite easiest to define the cursor name when you declare it, like this:
CREATE OR REPLACE FUNCTION function_1() RETURNS refcursor AS $$
DECLARE
ref_cursor REFCURSOR := 'mycursor';
BEGIN
OPEN ref_cursor FOR SELECT * FROM some_table;
RETURN (ref_cursor);
END;
$$ LANGUAGE plpgsql;
And then you can get it like this:
BEGIN;
SELECT function_1();
FETCH 4 from mycursor;
COMMIT;
I find this method less cumbersome.
Hope that helps.
Yes, use:
CREATE OR REPLACE FUNCTION function_1(refcursor) RETURNS refcursor AS $$
BEGIN
OPEN $1 FOR SELECT * FROM some_table;
RETURN $1;
END;
$$ LANGUAGE plpgsql;
Result:
SELECT function_1('myowncursorname');
function_1
-----------------
myowncursorname
(1 row)
It looks like auto-generated name is <unnamed portal n>, where n is natural number (from 1).
EDIT:
As another way you could use pg_cursors view with such query to obtain generated cursor name:
SELECT name FROM pg_cursors WHERE statement LIKE 'SELECT * FROM some_table';
For example:
BEGIN;
SELECT function_1();
SELECT name FROM pg_cursors WHERE statement LIKE 'SELECT * FROM some_table';
COMMIT;
Result:
function_1
--------------------
<unnamed portal 3>
(1 row)
name
--------------------
<unnamed portal 3>
(1 row)