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.



[begin_label:] REPEAT
    statement_list
UNTIL search_condition
END REPEAT [end_label]


Repeat until loop

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)


Using Repeat ... until to loop through a cursor

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)