Question

需要这个简单任务的帮助。此sp应该提供结果集，并将在MS-Access-Database报告中调用。

tablename是vvarying，但它以数字（lsid）结尾。使用Concatenatoin。 max_prepared_statement_count是默认值16382

有什么好主意吗？

THX 托马斯

CREATE DEFINER=`root2`@`%` PROCEDURE `sp_Quickview02`(IN lsid int)
BEGIN
set @tbl = concat('shape_tokens_',lsid); -- tablename

set @sql= 'select base.Status, count(base.token) as Anzahl 
                    from (select ?.completed, if(?.completed = ''N'',''offen'', ''abgeschlossen'') as Status,
            ?.token from ?) base group by base.status;'

PREPARE stmt FROM @sql; -- error is thrown here
EXECUTE stmt using @tbl;
DEALLOCATE PREPARE stmt;
END

Answer 1

如果检查变量@sql值，那么它将为您提供无法执行的输出，因此请更正。

SELECT base.Status, COUNT(base.token) AS Anzahl 
                    FROM (SELECT ?.completed, IF(?.completed = 'N','offen', 'abgeschlossen') AS STATUS,
            ?.token FROM ?) base GROUP BY base.status;

按以下方式更改 -

CREATE DEFINER=`root2`@`%` PROCEDURE `sp_Quickview02`(IN lsid int)
BEGIN
set @tbl = concat('shape_tokens_',lsid); -- tablename

SET @sql= CONCAT('select base.Status, count(base.token) as Anzahl 
                    from (select a.completed, if(a.completed = ''N'',''offen'', ''abgeschlossen'') as Status,
            a.token from ',@tbl,' as a) base group by base.status;');

PREPARE stmt FROM @sql; -- error is thrown here
EXECUTE stmt using @tbl;
DEALLOCATE PREPARE stmt;
END

Answer 2

查询需要4个参数，因此请使用执行查询，如下所示：

EXECUTE stmt using @tbl, @tbl, @tbl, @tbl;

准备stmt line thorws错误

2 个答案: