I'm new in POSTGRESQL and I am creating PostgreSQL functions, and now I want to create a function which returns two table output, I created and it does not work
my function
CREATE FUNCTION getData() RETURNS setof refcursor AS
$$
DECLARE c_top_items refcursor;
DECLARE c_shopping_cart refcursor;
BEGIN
OPEN c_top_items FOR
SELECT t.name
FROM employee t
LIMIT 10;
RETURN NEXT c_top_items;
OPEN c_shopping_cart FOR
SELECT c.name
FROM employee c
LIMIT 5;
RETURN NEXT c_shopping_cart;
END;
$$ LANGUAGE plpgsql;
Please help!!
When you call getData you get two cursors, fetch all from them. I modified the example in the documentation and fetched the data with:
select * from getData();
fetch all in "<unnamed portal 1>";
fetch all in "<unnamed portal 2>";
But you would probably be better off by changing the signature of the function according to the return multiple cursors-example in the documentation. This is that example:
CREATE FUNCTION myfunc(refcursor, refcursor) RETURNS SETOF refcursor AS $$
BEGIN
OPEN $1 FOR SELECT * FROM table_1;
RETURN NEXT $1;
OPEN $2 FOR SELECT * FROM table_2;
RETURN NEXT $2;
END;
$$ LANGUAGE plpgsql;
-- need to be in a transaction to use cursors.
BEGIN;
SELECT * FROM myfunc('a', 'b');
FETCH ALL FROM a;
FETCH ALL FROM b;
COMMIT;
See: Returning Cursors
Related
i want to get count of no.of rows present in table which i pass at runtime to a function.
i have created a procedure and function to execute dynamic queries. function will not allow dynamic query because i am calling procedure from function.
that procedure having dynamic query.
///////procedure///////
CREATE PROCEDURE bizopsgolddev.`test1`(tbnm varchar(100))
begin
declare sql_text varchar(200);
DECLARE EXIT HANDLER FOR SQLEXCEPTION
BEGIN
SELECT CONCAT(sql_text, ' is not valid');
END;
set sql_text=concat('select count(*) from ',tbnm);
SET #SQL := sql_text;
PREPARE stmt FROM #SQL;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
end;
//////function//////
DROP FUNCTION IF EXISTS xyz;
CREATE FUNCTION `xyz`(tname varchar(100)) RETURNS int(11)
begin
declare val int;
call test1(tname);
return 1;
end;
if i execute this //select xyz('axpdc')// it should return rows count
can any one tell me how can i get count by passing table name to function(in mariadb only)
As I understand the question, the solution would be a function that returns the row count of a table with it's name passed to the function as a parameter.
I think this could be done by querying the information_schema database in MariaDB. A function could look like this:
CREATE DEFINER = 'yourUsername'#'192.168.%'
FUNCTION testDataBase.fn_GetRowCount(tableName VARCHAR(128))
RETURNS int(11)
BEGIN
-- This could be a parameter if need it to be.
DECLARE databaseName varchar(40) DEFAULT 'testDataBase';
DECLARE result int DEFAULT -1;
SELECT t.TABLE_ROWS INTO result
FROM information_schema.TABLES t
WHERE t.TABLE_NAME = tableName
AND t.TABLE_SCHEMA = databaseName;
RETURN result;
END
In order for this to work the user mentioned as the definer must have read privilege to the TABLES table in the information_schema database, otherwise you might get an error (tbh, I don't know if this is necessary).
There is a lot of useful information to be grabbed from the information_schema database.
I am using mariadb 10.3.9, and have created a user defined aggregate function (UDAF) and placed in a common_schema. This schema contains my utility functions to be used by other schema/databases on the same server.
The issue is that when calling the UDAF while using any other schema, it always return NULL!
The following is to demonstrate the issue:
CREATE SCHEMA IF NOT EXISTS common_schema;
DELIMITER $$
DROP FUNCTION IF EXISTS common_schema.add_ints $$
CREATE FUNCTION common_schema.add_ints(int_1 INT, int_2 INT) RETURNS INT NO SQL
BEGIN
RETURN int_1 + int_2;
END $$
DROP FUNCTION IF EXISTS common_schema.sum_ints $$
CREATE AGGREGATE FUNCTION common_schema.sum_ints(int_val INT) RETURNS INT
BEGIN
DECLARE result INT DEFAULT 0;
DECLARE CONTINUE HANDLER FOR NOT FOUND RETURN result;
LOOP FETCH GROUP NEXT ROW;
SET result = common_schema.add_ints(result, int_val);
END LOOP;
END $$
DELIMITER ;
Now, calling it this way, returns the result as expected:
USE common_schema;
SELECT common_schema.sum_ints(seq)
FROM (SELECT 1 seq UNION ALL SELECT 2) t;
-- result: 3
Calling it using any other schema, it returns NULL:
USE other_schema;
SELECT common_schema.sum_ints(seq)
FROM (SELECT 1 seq UNION ALL SELECT 2) t;
-- result: null
Am I missing something here? Is there any configuration that is missing?
Appreciate your help.
Reported as a Bug https://jira.mariadb.org/browse/MDEV-18100.
As a workaround, create the UDAF in every schema.
I am trying to create a function that returns all values of the emp table Why do I get the error?
create or replace FUNCTION EMP_value
RETURN VARCHAR2
is
CURSOR a is select * from emp;
v_all emp%rowtype;
begin
open a;
LOOP
fetch a into v_all;
exit when a%notfound;
dbms_output.put_line(v_all.empno|| ' ' ||v_all.ename|| ' ' ||v_all.sal);
RETURN V_ALL;
end loop;
close a;
end;
Try to simplify your code as much as possible. If you want to return all the attributes of cursor from function, try using BULK collect and return it as complex data type. Here in this case its nested table type. Hope it helps.
--Create a schema level nested table type function
CREATE OR REPLACE TYPE emp_obj IS OBJECT
(
EMPNO NUMBER,
ENAME VARCHAR2(100),
SAL NUMBER,
MGR_NO NUMBER,
HIREDATE DATE
)
/
CREATE OR REPLACE TYPE emp_tab IS TABLE OF emp_obj
/
--Funtion to return all attributes from EMP tab
CREATE OR REPLACE FUNCTION EMP_value
RETURN emp_tab
AS
e_tab emp_tab;
begin
SELECT * BULK COLLECT INTO e_tab
FROM EMP;
RETURN e_tab;
end;
/
I need to run some SQL blocks to test them, is there an online app where I can insert the code and see what outcome it triggers?
Thanks a lot!
More specific question below:
<<block1>>
DECLARE
var NUMBER;
BEGIN
var := 3;
DBMS_OUTPUT.PUT_LINE(var);
<<block2>>
DECLARE
var NUMBER;
BEGIN
var := 200;
DBMS_OUTPUT.PUT_LINE(block1.var);
END block2;
DBMS_OUTPUT.PUT_LINE(var);
END block1;
Is the output:
3
3
200
or is it:
3
3
3
I read that the variable's value is the value received in the most recent block so is the second answer the good one? I'd love to test these online somewhere if there is a possibility.
Also, is <<block2>> really the correct way to name a block??
Later edit:
I tried this with SQL Fiddle, but I get a "Please build schema" error message:
Thank you very much, Dave! Any idea why this happens?
create table log_table
( message varchar2(200)
)
<<block1>>
DECLARE
var NUMBER;
BEGIN
var := 3;
insert into log_table(message) values (var)
select * from log_table
<<block2>>
DECLARE
var NUMBER;
BEGIN
var := 200;
insert into log_table(message) values (block1.var || ' 2nd')
select * from log_table
END block2;
insert into log_table(message) values (var || ' 3rd')
select * from log_table
END block1;
In answer to your three questions.
You can use SQL Fiddle with Oracle 11g R2: http://www.sqlfiddle.com/#!4. However, this does not allow you to use dbms_output. You will have to insert into / select from tables to see the results of your PL/SQL scripts.
The answer is 3 3 3. Once the inner block is END-ed the variables no longer exist/have scope. You cannot access them any further.
The block naming is correct, however, you aren't required to name blocks, they can be completely anonymous.
EDIT:
So after playing with SQL Fiddle a bit, it seems like it doesn't actually support named blocks (although I have an actual Oracle database to confirm what I said earlier).
You can, however, basically demonstrate the way variable scope works using stored procedures and inner procedures (which are incidentally two very important PL/SQL features).
Before I get to that, I noticed three issues with you code:
You need to terminate the insert statements with a semi-colon.
You need to commit the the transactions after the third insert.
In PL/SQL you can't simply do a select statement and get a result, you need to select into some variable. This would be a simple change, but because we can't use dbms_output to view the variable it doesn't help us. Instead do the inserts, then commit and afterwards select from the table.
In the left hand pane of SQL Fiddle set the query terminator to '//' then paste in the below and 'build schema':
create table log_table
( message varchar2(200)
)
//
create or replace procedure proc1 as
var NUMBER;
procedure proc2 as
var number;
begin
var := 200;
insert into log_table(message) values (proc1.var || ' 2nd');
end;
begin
var := 3;
insert into log_table(message) values (var || ' 1st');
proc2;
insert into log_table(message) values (var || ' 3rd');
commit;
end;
//
begin
proc1;
end;
//
Then in the right hand panel run this SQL:
select * from log_table
You can see that proc2.var has no scope outside of proc2. Furthermore, if you were to explicitly try to utilize proc2.var outside of proc2 you would raise an exception because it is out-of-scope.
I want to create a procedure that takes in a string, searches the table and the specified column for that string, and returns a 1 if it finds it and a zero if it does not. I am relatively new to SQL and do not know the syntax or commands very well. I want something like this:
CREATE PROCEDURE dbo.GetUsername
(
#Username NCHAR(10)
)
AS
#boolVariable
SELECT #Username FROM Accounts
RETURN #boolVariable
You don't return a value, but instead supply that in a result set.
CREATE PROCEDURE GetUsername
(
#Username NCHAR(10)
)
AS
SELECT Username FROM Accounts WHERE Username = #UserName;
In your calling code, simply check for the existence of a row in the result set.
I'm not sure if you're looking for mysql or mssql solution.
delimiter //
drop procedure if exists search_string //
create procedure search_string (in str varchar(100))
begin
declare b,r bool;
select count(*) into r from your_table where your_field = str;
if r > 0 then
set b = 1;
else
set b = 0;
end if;
select b;
end; //
delimiter //
call search_string('searched_string');