Checking flag : Condition HANDLER « Procedure Function « MySQL Tutorial






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 (0.02 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> delimiter $$
mysql> CREATE PROCEDURE myProc (in_customer_id INT)
    -> BEGIN
    ->
    ->      DECLARE l_first_name  VARCHAR(30);
    ->      DECLARE l_id          INT;
    ->      DECLARE l_city        VARCHAR(30);
    ->      DECLARE no_more_departments INT;
    ->
    ->      DECLARE dept_csr CURSOR FOR
    ->           SELECT id,first_name, city
    ->             FROM employee;
    ->      DECLARE CONTINUE HANDLER FOR NOT FOUND SET no_more_departments=1;
    ->
    ->
    ->      OPEN dept_csr;
    ->      dept_loop1:LOOP
    ->           FETCH dept_csr INTO l_id,l_first_name,l_city;
    ->
    ->           select l_id, l_first_name, l_city;
    ->           IF no_more_departments=1 THEN
    ->                LEAVE dept_loop1;
    ->           END IF;
    ->      END LOOP;
    ->      CLOSE dept_csr;
    ->      SET no_more_departments=0;
    ->
    ->
    ->
    -> END$$
Query OK, 0 rows affected (0.00 sec)

mysql> delimiter ;
mysql> call myProc(1);
+------+--------------+---------+
| l_id | l_first_name | l_city  |
+------+--------------+---------+
|    1 | Jason        | Toronto |
+------+--------------+---------+
1 row in set (0.00 sec)

+------+--------------+-----------+
| l_id | l_first_name | l_city    |
+------+--------------+-----------+
|    2 | Alison       | Vancouver |
+------+--------------+-----------+
1 row in set (0.01 sec)

+------+--------------+-----------+
| l_id | l_first_name | l_city    |
+------+--------------+-----------+
|    3 | James        | Vancouver |
+------+--------------+-----------+
1 row in set (0.01 sec)

+------+--------------+-----------+
| l_id | l_first_name | l_city    |
+------+--------------+-----------+
|    4 | Celia        | Vancouver |
+------+--------------+-----------+
1 row in set (0.01 sec)

+------+--------------+-----------+
| l_id | l_first_name | l_city    |
+------+--------------+-----------+
|    5 | Robert       | Vancouver |
+------+--------------+-----------+
1 row in set (0.01 sec)

+------+--------------+----------+
| l_id | l_first_name | l_city   |
+------+--------------+----------+
|    6 | Linda        | New York |
+------+--------------+----------+
1 row in set (0.01 sec)

+------+--------------+----------+
| l_id | l_first_name | l_city   |
+------+--------------+----------+
|    7 | David        | New York |
+------+--------------+----------+
1 row in set (0.01 sec)

+------+--------------+-----------+
| l_id | l_first_name | l_city    |
+------+--------------+-----------+
|    8 | James        | Vancouver |
+------+--------------+-----------+
1 row in set (0.01 sec)

+------+--------------+-----------+
| l_id | l_first_name | l_city    |
+------+--------------+-----------+
|    8 | James        | Vancouver |
+------+--------------+-----------+
1 row in set (0.01 sec)

Query OK, 0 rows affected (0.48 sec)

mysql> drop procedure myProc;
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql>
mysql>
mysql>
mysql> drop table Employee;
Query OK, 0 rows affected (0.00 sec)

mysql>
mysql>








11.44.Condition HANDLER
11.44.1.Declaring a Condition and Handler
11.44.2.Condition and Handler in action
11.44.3.DECLARE CONTINUE HANDLER FOR NOT FOUND SET
11.44.4.Checking flag
11.44.5.Using while to check the condition
11.44.6.DECLARE EXIT HANDLER FOR
11.44.7.Checking Exit flag
11.44.8.Using the IF statement to verify 'CONTINUE HANDLER'
11.44.9.The example associates a handler with SQLSTATE 23000, which occurs for a duplicate-key error
11.44.10.To ignore a condition