游标正在向表中插入空值

Question

我的光标仅在表中插入空值。在select子句中，我曾提到忽略空值，但它忽略了其他值并仅插入空值。

CREATE ` PROCEDURE `History`()
BEGIN
 DECLARE done INT DEFAULT 0;
 Declare  ProductName VARCHAR(40);

 DECLARE cur1 CURSOR FOR select 
  ProductName from products where  ProductName is not null ;
  DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;

 OPEN cur1;
  FETCH cur1 INTO  ProductName ;
   INSERT INTO  productdummy values ( ProductName );


  CLOSE cur1;


END