Question

我在使用mysql创建临时表时遇到了困难。

我有一个存储过程我正在创建一些sql语句我需要在我的sql中创建sql语句输出作为临时表。这是我的程序。有人帮我吗？

DELIMITER $$

CREATE DEFINER=`root`@`localhost` PROCEDURE `new_procedure`()
BEGIN

SET @sql = NULL;
SELECT
  GROUP_CONCAT(DISTINCT
    CONCAT(
      'MAX(CASE WHEN workspaceid = ''',
      workspaceid,
      ''' then "''''" ELSE NULL end) AS ',
      CONCAT('`',workspaceid,'`')
    )
  ) INTO @sql
FROM sms.hotelings;

SET @sql = CONCAT('SELECT t.Time, ', @sql, ' 
                   FROM sms.hotelings h, sms.hotelingtime t 
                   GROUP BY t.Time');

-- PREPARE stmt FROM @sql;
-- EXECUTE stmt;
-- DEALLOCATE PREPARE stmt;

CREATE TEMPORARY TABLE IF NOT EXISTS table2 AS @sql;
select * from table2
drop temporary table table2;
END

我想使用@sql语句创建一个临时表。

提前致谢。

Answer 1

如果要使用动态语句

，则必须使用PREPARE

SET @sql = CONCAT('CREATE TEMPORARY TABLE IF NOT EXISTS table2 AS SELECT t.Time, ', @sql, ' 
                   FROM sms.hotelings h, sms.hotelingtime t 
                   GROUP BY t.Time');
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SELECT * FROM table2;
DROP TEMPORARY TABLE table2;

在mysql中创建临时表时出错

1 个答案: