动态声明Cursor

Question

我需要根据我所处的情况在存储过程中动态创建游标,理想情况如下:

IF (varOrgGroupCode = '') THEN
BEGIN
DECLARE groupCode CURSOR FOR
SELECT `groupcode` FROM `LICENSEKEYS`;
END;
ELSE
BEGIN
DECLARE groupCode CURSOR FOR
SELECT `groupcode` FROM `LICENSEKEYS` WHERE `groupcode` = varOrgGroupCode;  
END;
END IF;

上面的代码将导致语法错误.我用谷歌搜索,有人用临时表做了.谁能告诉我怎么样？

Answer 1

可能你在Google上找到的东西是创建一个临时表,根据你的谓词填充临时表,然后在你的游标声明中引用临时表.

像这样的东西:

DELIMITER $$

CREATE PROCEDURE `some_procedure`(IN varOrgGroupCode varchar(100))
BEGIN

DECLARE bNoMoreRows BOOLEAN DEFAULT FALSE;
DECLARE vGroupCode varchar(100);

DECLARE groupCode CURSOR FOR
SELECT `groupcode` FROM `LICENSEKEYS_TEMP`;

declare continue handler for not found set bNoMoreRows := true; 

BEGIN

  drop table if exists LICENSEKEYS_TEMP;

  create temporary table `LICENSEKEYS_TEMP` (groupCode varchar(100));

  IF (varOrgGroupCode = '') THEN
    insert into `LICENSEKEYS_TEMP` (groupCode) SELECT `groupcode` FROM `LICENSEKEYS`;
  ELSE
    insert into `LICENSEKEYS_TEMP` (groupCode) SELECT `groupcode` FROM `LICENSEKEYS` WHERE `groupcode` = varOrgGroupCode;  
  END IF;

  open groupCode;

  GROUPCODE_LOOP: loop

   fetch groupCode into vGroupCode;

   -- Do some stuff

   if bNoMoreRows then
      close groupCode;
      leave GROUPCODE_LOOP;
   end if;

  END LOOP GROUPCODE_LOOP;

 END;

END$$

DELIMITER ;