如何在此过程中构建动态查询

Question

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 - 你的 SQL 语法有误；查看与您的 MariaDB 服务器版本对应的手册，了解在第 7 行

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

Answer 1

我不知道你的存储过程是做什么的...但固定版本是：它有几个错误：

必须设置默认分隔符，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' ';

必须改为

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 $$

如何在此过程中构建动态查询

How to build dynamic query into this procedure

mysql

stored-procedures

mariadb

1064 - 你的 SQL 语法有误；查看与您的 MariaDB 服务器版本对应的手册，了解在第 7 行