【问题标题】：How to build dynamic query into this procedure如何在此过程中构建动态查询
【发布时间】：2017-08-05 02:55:31
【问题描述】：

我正在尝试使用 mysql 数据库中的存储过程构建动态查询，但仍然看到此错误。为什么？

1064 - 您的 SQL 语法有错误；检查与您的 MariaDB 服务器版本相对应的手册，以了解在第 7 行的 '' 附近使用的正确语法

DROP PROCEDURE IF EXISTS mp_test;
CREATE PROCEDURE mp_test(
    IN PrStatus VARCHAR(255),
    IN PrStatusCode VARCHAR(255),
    IN PrProviderId VARCHAR(255),
    IN PrRow VARCHAR(255))
   BEGIN
      SET @Condition  = '';
      SET @Query = '   
      SELECT
      bitauth_users.fullname,
      tbservices.ServiceNameAR,
      tbservices.ServiceNameEN,
      tbservices.ServiceId,
      globrx.ProviderId,
      globrx.RequestDesc,
      TbServicesRequestsLog.status
        FROM tbservices, Tbservicesrequests globrx, 
        TbServicesRequestsLog, bitauth_users  
        WHERE  globrx.ProviderId = 'Prproviderid' ';

      IF PrStatus != '' THEN
         SET @Condition = CONCAT(' AND globrx.RequestId = TbServicesRequestsLog.RequestId');
         SET @Condition = CONCAT(' AND globrx.ServiceId = tbservices.ServiceId');
         SET @Condition = CONCAT(' AND bitauth_users.user_id = globrx.ReceiverId');
         SET @Condition = CONCAT(' AND globrx.RequestId = TbServicesRequestsLog.RequestId');
         SET @Condition = CONCAT('AND (SELECT status  FROM TbServicesRequestsLog,Tbservicesrequests AS subrx
                                  WHERE subrx.RequestId = TbServicesRequestsLog.RequestId 
                                  AND subrx.ServiceId = globrx.ServiceId
                                  ORDER BY RequestLogId DESC  LIMIT 1)"', status_code, '"');
         SET @Condition = CONCAT('GROUP BY TbServices.ServiceId ORDER BY TbServices.ServiceId ASC LIMIT 'PrRow',10')
               
                                  
      END IF;
      
      SET @Query = CONCAT(@Query, @Condition);

 PREPARE stmt FROM @Query;
 
 EXECUTE stmt;
 DEALLOCATE PREPARE stmt;  
END

【问题讨论】：

WHERE globrx.ProviderId = 'Prproviderid' ' 行似乎不对。 MySQL 不是 php，它不会在字符串中扩展变量。您需要使用concat()。另外，你的分隔符声明在哪里？
你的意思是使用 concat 和 @Query var ？
是的，我愿意。但比尔也在他的回答中指出了这一点。
好的，我试过了，但没有修复错误
我已经删除了我的答案。我不喜欢因为我的努力而遭到反对。

标签： mysql stored-procedures mariadb

【解决方案1】：

我不知道你的存储过程是什么......但固定版本是：它有几个错误：

必须将分隔符设置为默认值，因为正文将包含 ; ，第一行我把分隔符改成了$$

连接不是自动的：

WHERE  globrx.ProviderId = 'Prproviderid' ';

必须改成

concat('...
WHERE  globrx.ProviderId = ',Prproviderid,' ');

@condition 是一个累积变量（我认为）：
```
SET @Condition = CONCAT(@Condition,
```

有结果：

DELIMITER $$
DROP PROCEDURE IF EXISTS mp_test$$
CREATE PROCEDURE mp_test(
    IN PrStatus VARCHAR(255),
    IN PrStatusCode VARCHAR(255),
    IN PrProviderId VARCHAR(255),
    IN PrRow VARCHAR(255))
   BEGIN
      SET @Condition  = '';
      SET @Query = concat('   
      SELECT
      bitauth_users.fullname,
      tbservices.ServiceNameAR,
      tbservices.ServiceNameEN,
      tbservices.ServiceId,
      globrx.ProviderId,
      globrx.RequestDesc,
      TbServicesRequestsLog.status
        FROM tbservices, Tbservicesrequests globrx, 
        TbServicesRequestsLog, bitauth_users  
        WHERE  globrx.ProviderId = ',Prproviderid,' ');

    SET @Condition = '';

      IF PrStatus != '' THEN
         SET @Condition = CONCAT(@Condition,' AND globrx.RequestId = TbServicesRequestsLog.RequestId');
         SET @Condition = CONCAT(@Condition,' AND globrx.ServiceId = tbservices.ServiceId');
         SET @Condition = CONCAT(@Condition,' AND bitauth_users.user_id = globrx.ReceiverId');
         SET @Condition = CONCAT(@Condition,' AND globrx.RequestId = TbServicesRequestsLog.RequestId');
         SET @Condition = CONCAT(@Condition,' AND (SELECT status  FROM TbServicesRequestsLog,Tbservicesrequests AS subrx
                                  WHERE subrx.RequestId = TbServicesRequestsLog.RequestId 
                                  AND subrx.ServiceId = globrx.ServiceId
                                  ORDER BY RequestLogId DESC  LIMIT 1) "', status_code, '"');
         SET @Condition = CONCAT(@Condition,' GROUP BY TbServices.ServiceId ORDER BY TbServices.ServiceId ASC LIMIT ',PrRow,',10');


      END IF;

      SET @Query = CONCAT(@Query, @Condition);

    PREPARE stmt FROM @Query;

    EXECUTE stmt;
    DEALLOCATE PREPARE stmt;  
END $$

【讨论】：