MySQL Tutorial/Procedure Function/Repeat until

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REPEAT Statement

To loop over a set of statements until a post-statement condition is met, use the REPEAT statement.



   <source lang="sql">

[begin_label:] REPEAT

   statement_list

UNTIL search_condition END REPEAT [end_label]</source>


Repeat until loop

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mysql> mysql> delimiter // mysql> create procedure test_repeat (IN in_count INT)

   -> BEGIN
   ->     declare count INT default 0;
   ->
   ->     increment: repeat
   ->         set count = count + 1;
   ->         select count;
   ->         until count > 10
   ->     end repeat increment;
   ->
   -> END
   -> //

Query OK, 0 rows affected (0.00 sec) mysql> mysql> delimiter ; mysql> mysql> call test_repeat(10); +-------+ | count | +-------+ | 1 | +-------+ 1 row in set (0.00 sec) +-------+ | count | +-------+ | 2 | +-------+ 1 row in set (0.00 sec) +-------+ | count | +-------+ | 3 | +-------+ 1 row in set (0.01 sec) +-------+ | count | +-------+ | 4 | +-------+ 1 row in set (0.01 sec) +-------+ | count | +-------+ | 5 | +-------+ 1 row in set (0.01 sec) +-------+ | count | +-------+ | 6 | +-------+ 1 row in set (0.01 sec) +-------+ | count | +-------+ | 7 | +-------+ 1 row in set (0.01 sec) +-------+ | count | +-------+ | 8 | +-------+ 1 row in set (0.01 sec) +-------+ | count | +-------+ | 9 | +-------+ 1 row in set (0.01 sec) +-------+ | count | +-------+ | 10 | +-------+ 1 row in set (0.01 sec) +-------+ | count | +-------+ | 11 | +-------+ 1 row in set (0.01 sec) Query OK, 0 rows affected (0.01 sec) mysql> mysql> drop procedure test_repeat; Query OK, 0 rows affected (0.00 sec)</source>


Using Repeat ... until to loop through a cursor

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mysql> mysql> mysql> CREATE TABLE Employee(

   ->     id            int,
   ->     first_name    VARCHAR(15),
   ->     last_name     VARCHAR(15),
   ->     start_date    DATE,
   ->     end_date      DATE,
   ->     salary        FLOAT(8,2),
   ->     city          VARCHAR(10),
   ->     description   VARCHAR(15)
   -> );

Query OK, 0 rows affected (0.03 sec) mysql> mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)

   ->              values (1,"Jason",    "Martin",  "19960725",  "20060725", 1234.56, "Toronto",  "Programmer");

Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)

   ->               values(2,"Alison",   "Mathews",  "19760321", "19860221", 6661.78, "Vancouver","Tester");

Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)

   ->               values(3,"James",    "Smith",    "19781212", "19900315", 6544.78, "Vancouver","Tester");

Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)

   ->               values(4,"Celia",    "Rice",     "19821024", "19990421", 2344.78, "Vancouver","Manager");

Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)

   ->               values(5,"Robert",   "Black",    "19840115", "19980808", 2334.78, "Vancouver","Tester");

Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)

   ->               values(6,"Linda",    "Green",    "19870730", "19960104", 4322.78,"New York",  "Tester");

Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)

   ->               values(7,"David",    "Larry",    "19901231", "19980212", 7897.78,"New York",  "Manager");

Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)

   ->               values(8,"James",    "Cat",     "19960917",  "20020415", 1232.78,"Vancouver", "Tester");

Query OK, 1 row affected (0.00 sec) mysql> mysql> select * from Employee; +------+------------+-----------+------------+------------+---------+-----------+-------------+ | id | first_name | last_name | start_date | end_date | salary | city | description | +------+------------+-----------+------------+------------+---------+-----------+-------------+ | 1 | Jason | Martin | 1996-07-25 | 2006-07-25 | 1234.56 | Toronto | Programmer | | 2 | Alison | Mathews | 1976-03-21 | 1986-02-21 | 6661.78 | Vancouver | Tester | | 3 | James | Smith | 1978-12-12 | 1990-03-15 | 6544.78 | Vancouver | Tester | | 4 | Celia | Rice | 1982-10-24 | 1999-04-21 | 2344.78 | Vancouver | Manager | | 5 | Robert | Black | 1984-01-15 | 1998-08-08 | 2334.78 | Vancouver | Tester | | 6 | Linda | Green | 1987-07-30 | 1996-01-04 | 4322.78 | New York | Tester | | 7 | David | Larry | 1990-12-31 | 1998-02-12 | 7897.78 | New York | Manager | | 8 | James | Cat | 1996-09-17 | 2002-04-15 | 1232.78 | Vancouver | Tester | +------+------------+-----------+------------+------------+---------+-----------+-------------+ 8 rows in set (0.00 sec) mysql> mysql> mysql> mysql> mysql> delimiter $$ mysql> CREATE PROCEDURE myProc (in_customer_id INT)

   -> BEGIN
   ->
   ->      DECLARE l_first_name  VARCHAR(30);
   ->      DECLARE l_id          INT;
   ->      DECLARE l_city        VARCHAR(30);
   ->      DECLARE l_department_count INT;
   ->      DECLARE no_more_departments INT;
   ->
   ->      DECLARE dept_csr CURSOR FOR
   ->           SELECT id,first_name, city
   ->             FROM employee;
   ->
   ->      DECLARE CONTINUE HANDLER FOR NOT FOUND SET no_more_departments=1;
   ->
   ->      SET no_more_departments=0;
   ->      OPEN dept_csr;
   ->      dept_loop:REPEAT
   ->           FETCH dept_csr INTO l_id,l_first_name,l_city;
   ->               IF no_more_departments=0 THEN
   ->                 SET l_department_count=l_department_count+1;
   ->               END IF;
   ->           select  l_id,l_first_name,l_city;
   ->      UNTIL no_more_departments
   ->      END REPEAT dept_loop;
   ->      CLOSE dept_csr;
   ->      SET no_more_departments=0;
   ->
   ->
   -> END$$

Query OK, 0 rows affected (0.00 sec) mysql> delimiter ; mysql> mysql> call myProc(1); +------+--------------+---------+ | l_id | l_first_name | l_city | +------+--------------+---------+ | 1 | Jason | Toronto | +------+--------------+---------+ 1 row in set (0.02 sec) +------+--------------+-----------+ | l_id | l_first_name | l_city | +------+--------------+-----------+ | 2 | Alison | Vancouver | +------+--------------+-----------+ 1 row in set (0.02 sec) +------+--------------+-----------+ | l_id | l_first_name | l_city | +------+--------------+-----------+ | 3 | James | Vancouver | +------+--------------+-----------+ 1 row in set (0.02 sec) +------+--------------+-----------+ | l_id | l_first_name | l_city | +------+--------------+-----------+ | 4 | Celia | Vancouver | +------+--------------+-----------+ 1 row in set (0.02 sec) +------+--------------+-----------+ | l_id | l_first_name | l_city | +------+--------------+-----------+ | 5 | Robert | Vancouver | +------+--------------+-----------+ 1 row in set (0.02 sec) +------+--------------+----------+ | l_id | l_first_name | l_city | +------+--------------+----------+ | 6 | Linda | New York | +------+--------------+----------+ 1 row in set (0.02 sec) +------+--------------+----------+ | l_id | l_first_name | l_city | +------+--------------+----------+ | 7 | David | New York | +------+--------------+----------+ 1 row in set (0.03 sec) +------+--------------+-----------+ | l_id | l_first_name | l_city | +------+--------------+-----------+ | 8 | James | Vancouver | +------+--------------+-----------+ 1 row in set (0.03 sec) +------+--------------+-----------+ | l_id | l_first_name | l_city | +------+--------------+-----------+ | 8 | James | Vancouver | +------+--------------+-----------+ 1 row in set (0.38 sec) Query OK, 0 rows affected (0.38 sec) mysql> drop procedure myProc; Query OK, 0 rows affected (0.02 sec) mysql> mysql> mysql> mysql> drop table Employee; Query OK, 0 rows affected (0.00 sec)</source>