i'm having hard time with my homework , because im beginner using mysql procedure.
to search total numbers odd and even between 20-50 with looping.
i want to make output like this using mysql procedure to call:
total_odd_numbers :15
total_even_numbers:16
i tried for sum up for even numbers like this :
`DELIMITER $$
CREATE DEFINER=`root`#`localhost` PROCEDURE `genap`()
BEGIN
DECLARE x INT;
DECLARE str VARCHAR(255);
declare total int;
SET x = 20;
SET str = '';
set total = 0;
loop_label: LOOP
IF x = 50 THEN
LEAVE loop_label;
END IF;
SET x =x+1;
IF (x mod 2) THEN
ITERATE loop_label;
ELSE
SET str = CONCAT(str,x,',');
SET total= total+x;
END IF;
END LOOP;
SELECT sum(total);
END`
Try this procedure:
DROP PROCEDURE IF EXISTS ShowOddEvesBetween;
DELIMITER ;;
CREATE PROCEDURE ShowOddEvesBetween(IN fromNum INT, IN toNum INT)
BEGIN
DECLARE odds INT DEFAULT 0;
DECLARE evens INT DEFAULT 0;
DECLARE x INT;
SET x = fromNum;
WHILE x <= toNum DO
IF x % 2 THEN
SET odds = odds + 1;
ELSE
SET evens = evens + 1;
END IF;
SET x = x + 1;
END WHILE;
SELECT CONCAT("total_odd_numbers: ", odds, ", total_even_numbers: ", evens) AS "Odds & Evens";
END;
;;
Then call it
CALL ShowOddEvesBetween(20, 50);
Will output what you want
MariaDB [test]> CALL ShowOddEvesBetween(20, 50);
+-----------------------------------------------+
| Odds & Evens |
+-----------------------------------------------+
| total_odd_numbers: 15, total_even_numbers: 16 |
+-----------------------------------------------+
1 row in set (0.00 sec)
Related
i tried my best to have a better title for the question but thats all i could make up. Well i will try to explain it by giving an example. Assume i have: Set x = 100200300;
Set y = 10; B
Now i want to add y into all first 3 numbers which is “100” then add it into “200” and so on. I was wondering if i can do it with “select left” function inside a loop? Not sure how to apply it tho therefore i am seeking for help here. Help me please. Bless
DELIMITER $$
CREATE PROCEDURE proc(
)
BEGIN
DECLARE counter INT DEFAULT 1;
set #x = '100200300400';
set #y = 10;
WHILE counter <= #x DO
select concat(substring(#x,counter,3) + #y,substring(#x,(counter +3),3) + #y) x;
END WHILE;
END$$
DELIMITER ;
Perhaps
SET #X = 100200300;
SET #Y = 10;
select concat(substring(#x,1,3) + #y,substring(#x,4,3) + #y,substring(#x,7,3) + #y) x;
+-----------+
| x |
+-----------+
| 110210310 |
+-----------+
1 row in set (0.001 sec)
If x is of unknown length
DROP PROCEDURE IF EXISTS P;
DELIMITER $$
CREATE PROCEDURE p(
)
BEGIN
DECLARE counter INT DEFAULT 1;
set #x = '100200300400';
set #y = 10;
SET #OUT = '';
L:WHILE counter <= #x / 3 DO
#SELECT COUNTER;
IF #x is null or COUNTER > 10 THEN LEAVE L; END IF;
SET #OUT = CONCAT(#OUT,substring(#x,counter,3) + #y);
SET #X = REPLACE(#X,#out,'');
#select concat(substring(#x,counter,3) + #y,substring(#x,(counter +3),3) + #y) x;
SET COUNTER = COUNTER + 3;
END WHILE;
select #out;
END $$
DELIMITER ;
CALL P();
DELIMITER ;
I'm looking to do some validation of data replication between some different database systems, with different character sets (potentially) and a third party software that migrates the data. To help test an aspect of this, I'm looking to do something like the following.
ASCII(foo) returns the value for the first character in the string. Is there a way to get the ascii values for all characters in a string in one go, in one select statement? Something like concating the values together, separated by a space. E.g. If the string was hello then the output would be 104 101 108 108 111
Reference:
select ascii('h'); -- 104
select ascii('e'); -- 101
select ascii('l'); -- 108
select ascii('o'); -- 111
Just had the same problem, so here is a procedure that does the work:
DELIMITER $$
CREATE PROCEDURE string_to_ascii(IN inputStr VARCHAR(255))
BEGIN
DECLARE strLen INT DEFAULT 0;
DECLARE idx INT DEFAULT 0;
DECLARE current_char VARCHAR(1);
DECLARE current_char_ascii VARCHAR(10);
DECLARE outputStr TEXT;
IF inputStr IS NULL THEN
SET inputStr = '';
END IF;
SET strLen = CHAR_LENGTH(inputStr);
SET idx = 1;
WHILE idx <= strLen DO
SET current_char = SUBSTR(inputStr, idx, 1);
SET current_char_ascii = ASCII(current_char);
IF idx = 1 THEN
SET outputStr = current_char_ascii;
ELSE
SET outputStr = CONCAT(outputStr, ",", current_char_ascii);
END IF;
SET idx = idx+1;
END WHILE;
SELECT outputStr;
END
$$
DELIMITER ;
Usage:
> CALL string_to_ascii('hello');
+---------------------+
| outputStr |
+---------------------+
| 104,101,108,108,111 |
+---------------------+
If you prefer to use it as a function:
DELIMITER //
CREATE FUNCTION string_to_ascii ( inputStr TEXT )
RETURNS TEXT
DETERMINISTIC
BEGIN
DECLARE strLen INT DEFAULT 0;
DECLARE idx INT DEFAULT 0;
DECLARE current_char VARCHAR(1);
DECLARE current_char_ascii VARCHAR(10);
DECLARE outputStr TEXT;
IF inputStr IS NULL THEN
SET inputStr = '';
END IF;
SET strLen = CHAR_LENGTH(inputStr);
SET idx = 1;
WHILE idx <= strLen DO
SET current_char = SUBSTR(inputStr, idx, 1);
SET current_char_ascii = ASCII(current_char);
IF idx = 1 THEN
SET outputStr = current_char_ascii;
ELSE
SET outputStr = CONCAT(outputStr, ",", current_char_ascii);
END IF;
SET idx = idx+1;
END WHILE;
RETURN outputStr;
END; //
DELIMITER ;
And then the usage will be:
> SELECT string_to_ascii('hello');
+--------------------------+
| string_to_ascii('hello') |
+--------------------------+
| 104,101,108,108,111 |
+--------------------------+
I need to convert this tSQL query into MySQL query version 5.7.14
I tried declare parameter with the following syntax
declare #commissionType INT;
but I reached a dead end and need help to convert this query
CREATE PROCEDURE MyProc
#chainId int
as
BEGIN
declare #commissionMethod int
declare #commissionType int
declare #value decimal(18,2)
set #commissionMethod = 1
set #value = 200000
set #commissionType = (select CommissionType from CommissionRules
where ChainId = #chainId )
IF(#commissionMethod = 1)
BEGIN
print('alert')
select (Fixed * #value) / 100 from CommissionRules where ChainId = #chainId
END
END
This is pretty much a literal conversion. But check your logic. It doesn't make any sense. v_commissionMethod is always 1 and v_commissionType is not even being used after selecting a value.
DELIMITER //
CREATE PROCEDURE MyProc (
p_chainId int)
BEGIN
declare v_commissionMethod int;
declare v_commissionType int;
declare v_value decimal(18,2);
set v_commissionMethod = 1;
set v_value = 200000;
select CommissionType into v_commissionType from CommissionRules
where ChainId = p_chainId ;
IF(v_commissionMethod = 1)
THEN
/* print('alert') */
select (Fixed * v_value) / 100 from CommissionRules where ChainId = p_chainId;
END IF;
END;
//
DELIMITER ;
Something like this:
DELIMITER $$
CREATE PROCEDURE MyProc (
in_chainId unsigned
) as
BEGIN
select v_CommissionType := CommissionType,
v_commissionMethod = 1,
v_value = 200000
from CommissionRules
where ChainId = in_chainId;
if v_commissionMethod = 1 then
select 'alert';
select (Fixed * v_value) / 100
from CommissionRules
where ChainId = in_chainId
end if;
END;$$
DELIMITER ;
I am trying to build a variable name dynamically within a user defined function but it seems it does not work. Is there a way to do this or by using an array variable?
I have a string of 7 characters which represents the days of the week (1234567, or 1_3_5_7, etc.). I would like evaluate how often during a week a day is selected (from 0 to 7). I thought, it would be easiest to use a loop to go through all the 7 positions but I get an error message saying
[Err] 1193 - Unknown system variable 'CONCAT'
Any hints on how I can achieve that? This is my code:
DELIMITER $$
DROP FUNCTION IF EXISTS fn_freq$$
CREATE FUNCTION fn_freq(days INT) RETURNS INT
BEGIN
DECLARE D1 VARCHAR(1);
DECLARE D2 VARCHAR(1);
DECLARE D3 VARCHAR(1);
DECLARE D4 VARCHAR(1);
DECLARE D5 VARCHAR(1);
DECLARE D6 VARCHAR(1);
DECLARE D7 VARCHAR(1);
DECLARE x INT;
DECLARE fn_freq INT;
SET x =1;
SET fn_freq = 0;
WHILE x < 8 DO
SET CONCAT('D',x) = MID(days, x, 1);
IF CONCAT('D',x) = '_' THEN
ELSE
SET fn_freq = fn_freq + 1;
SET x = x + 1;
END IF;
SET x = x + 1;
END WHILE;
RETURN fn_freq;
END$$
DELIMITER ;
You cant SET CONCAT as in SET CONCAT('D',x) = MID(days, x, 1) what instead i think will be better to declare & set the concat value to that variable and use that variable for the IF condition. Also I think you missed out what have to be done in the case IF Condition is true.
Thanks for your reply. I got it to work like this, but I am still curious, how I could dynamically create a variable in some other cases.
For this function, I realized I don't even need the variable, as I can evaluate it straight in the if clause.
DELIMITER $$
DROP FUNCTION IF EXISTS fn_freq$$
CREATE FUNCTION fn_freq(days VarChar(7)) RETURNS INT
BEGIN
DECLARE x INT;
DECLARE fn_freq INT;
SET x =1, fn_freq = 0;
WHILE x < 8 DO
IF MID(days, x, 1) <> '_' THEN
SET fn_freq = fn_freq + 1;
END IF;
SET x = x + 1;
END WHILE;
RETURN fn_freq;
END$$
DELIMITER ;
In MySQL, I have this stored procedure with a LOOP:
DELIMITER $$
CREATE PROCEDURE ABC()
BEGIN
DECLARE a INT Default 0 ;
simple_loop: LOOP
SET a=a+1;
select a;
IF a=5 THEN
LEAVE simple_loop;
END IF;
END LOOP simple_loop;
END $$
It always prints 1. What is the correct syntax for a MySQL Loop?
drop table if exists foo;
create table foo
(
id int unsigned not null auto_increment primary key,
val smallint unsigned not null default 0
)
engine=innodb;
drop procedure if exists load_foo_test_data;
delimiter #
create procedure load_foo_test_data()
begin
declare v_max int unsigned default 1000;
declare v_counter int unsigned default 0;
truncate table foo;
start transaction;
while v_counter < v_max do
insert into foo (val) values ( floor(0 + (rand() * 65535)) );
set v_counter=v_counter+1;
end while;
commit;
end #
delimiter ;
call load_foo_test_data();
select * from foo order by id;
While loop syntax example in MySQL:
delimiter //
CREATE procedure yourdatabase.while_example()
wholeblock:BEGIN
declare str VARCHAR(255) default '';
declare x INT default 0;
SET x = 1;
WHILE x <= 5 DO
SET str = CONCAT(str,x,',');
SET x = x + 1;
END WHILE;
select str;
END//
Which prints:
mysql> call while_example();
+------------+
| str |
+------------+
| 1,2,3,4,5, |
+------------+
REPEAT loop syntax example in MySQL:
delimiter //
CREATE procedure yourdb.repeat_loop_example()
wholeblock:BEGIN
DECLARE x INT;
DECLARE str VARCHAR(255);
SET x = 5;
SET str = '';
REPEAT
SET str = CONCAT(str,x,',');
SET x = x - 1;
UNTIL x <= 0
END REPEAT;
SELECT str;
END//
Which prints:
mysql> call repeat_loop_example();
+------------+
| str |
+------------+
| 5,4,3,2,1, |
+------------+
FOR loop syntax example in MySQL:
delimiter //
CREATE procedure yourdatabase.for_loop_example()
wholeblock:BEGIN
DECLARE x INT;
DECLARE str VARCHAR(255);
SET x = -5;
SET str = '';
loop_label: LOOP
IF x > 0 THEN
LEAVE loop_label;
END IF;
SET str = CONCAT(str,x,',');
SET x = x + 1;
ITERATE loop_label;
END LOOP;
SELECT str;
END//
Which prints:
mysql> call for_loop_example();
+-------------------+
| str |
+-------------------+
| -5,-4,-3,-2,-1,0, |
+-------------------+
1 row in set (0.00 sec)
Do the tutorial: http://www.mysqltutorial.org/stored-procedures-loop.aspx
If I catch you pushing this kind of MySQL for-loop constructs into production, I'm going to shoot you with the foam missile launcher. You can use a pipe wrench to bang in a nail, but doing so makes you look silly.
Assume you have one table with name 'table1'. It contain one column 'col1' with varchar type. Query to crate table is give below
CREATE TABLE `table1` (
`col1` VARCHAR(50) NULL DEFAULT NULL
)
Now if you want to insert number from 1 to 50 in that table then use following stored procedure
DELIMITER $$
CREATE PROCEDURE ABC()
BEGIN
DECLARE a INT Default 1 ;
simple_loop: LOOP
insert into table1 values(a);
SET a=a+1;
IF a=51 THEN
LEAVE simple_loop;
END IF;
END LOOP simple_loop;
END $$
To call that stored procedure use
CALL `ABC`()
You can exchange this local variable for a global, it would be easier.
DROP PROCEDURE IF EXISTS ABC;
DELIMITER $$
CREATE PROCEDURE ABC()
BEGIN
SET #a = 0;
simple_loop: LOOP
SET #a=#a+1;
select #a;
IF #a=5 THEN
LEAVE simple_loop;
END IF;
END LOOP simple_loop;
END $$