How to convert a SQL Server cursor to MySQL equivalent

Question

How can I convert the procedure below to MySQL format?

Here is the piece to be converted:

DECLARE @CurrentFirstName varchar(300)
DECLARE @CurrentAge          


        

Answer 1

The MySQL equivalent would be something like this:

BEGIN
  DECLARE CurrentFirstName VARCHAR(300);
  DECLARE CurrentAge INT;
  DECLARE done INT DEFAULT FALSE;
  DECLARE CursorName CURSOR FOR
    SELECT FirstName, Age FROM Customers;
  DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
  OPEN CursorName;
  myloop: LOOP
    FETCH CursorName INTO CurrentFirstName, CurrentAge;
    IF done THEN
      LEAVE myloop;
    END IF;
    IF CurrentAge > 60 THEN
      insert into ElderCustomers values (CurrentFirstName,CurrentAge);
    END IF;
  END LOOP;
  CLOSE CursorName;
END;

The big difference is in the loop, using the CONTINUE HANDLER to set a flag when there are no more rows to fetch, and exiting the loop when the flag is set. (That looks ugly, but that's the way it's done in MySQL.)

This example begs the question why this isn't written (more efficiently, in both SQL Server and MySQL) as:

INSERT INTO ElderCustomers (FirstName, Age)
SELECT FirstName, Age
  FROM Customers
 WHERE Age > 60