动态声明游标

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。我用谷歌搜索过&有人通过使用临时表来做到这一点。谁能告诉我怎么办？

Answer 1

您在 Google 上找到的内容可能是创建一个临时表，根据您的谓词填充该临时表，然后在游标声明中引用该临时表。

像这样的事情：

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 ;