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我正在尝试执行动态查询，因为我正在使用 CONCAT() 函数。但我认为我的字符串/查询很长，所以 CONCAT() 不起作用。

set @query:=CONCAT(' SELECT (select GROUP_CONCAT(sp.specialization) FROM DSpecialization_Master dsp LEFT JOIN 
Specialization_Master sp on sp.id = dsp.specialization WHERE dsp.profileid in (', @MultiDoctorIds ,') 
) as drspec,pm.id as profileid,dam.city,um.profile_url FROM Profile_Master pm LEFT JOIN DAddress_Master dam on 
dam.profileid = pm.id join Unique_Url_Master um on um.clinicid =dam.id WHERE pm.id in (',@MultiDoctorIds,') 
and dam.id=',@clinicId,'  order by CASE WHEN um.clinic_url=''',@ClinicUrl,''' THEN 1 ELSE 2  end,um.clinic_url   ');

select @query;

这是我执行 SP 时存储过程的一部分，它向我显示@query NULL但如果我缩短查询，那么我会得到完整的查询。

还有另一种连接方式吗？

任何帮助表示赞赏。

4

3 回答 3

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temporary solution为此，将您的存储dynamic query在local variable而不是sessional variable使用maximum length下面的 .like

Declare temp_query varchar(4000);

set @query:=CONCAT(' SELECT (select GROUP_CONCAT(sp.specialization) FROM DSpecialization_Master dsp LEFT JOIN 
Specialization_Master sp on sp.id = dsp.specialization WHERE dsp.profileid in (', @MultiDoctorIds ,') 
) as drspec,pm.id as profileid,dam.city,um.profile_url FROM Profile_Master pm LEFT JOIN DAddress_Master dam on 
dam.profileid = pm.id join Unique_Url_Master um on um.clinicid =dam.id WHERE pm.id in (',@MultiDoctorIds,') 
and dam.id=',@clinicId,'  order by CASE WHEN um.clinic_url=''',@ClinicUrl,''' THEN 1 ELSE 2  end,um.clinic_url   ');

select @query into temp_query;
select temp_query;
于 2016-04-07T11:43:37.007 回答
0

您可以设置一个变量，如

SET @var := hello hello

你必须引用它

MariaDB [(none)]> set @var = hello hello;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'hello' at line 1
MariaDB [(none)]> set @var = "hello hello";
Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> select @var;
+-------------+
| @var        |
+-------------+
| hello hello |
+-------------+
1 row in set (0.00 sec)

MariaDB [(none)]>
于 2016-04-07T11:45:04.327 回答
0

我得到了另一个解决方案：

GROUP_CONCAT最大长度是(1024 by default)你应该改变它的会话范围长度的限制，如下所示，这将解决你的问题

  SET SESSION group_concat_max_len = 25000 ;
于 2016-04-09T09:34:44.643 回答