sql group by 左连接答案

【问题标题】：sql group by with left joinsql group by 左连接
【发布时间】：2011-02-07 18:00:43
【问题描述】：

fail statement:Error: ORA-00979: not a GROUP BY expression

 select org_division.name  , org_department.name , org_surveylog.division_code as divisionCode,org_surveylog.department_code as departmentCode , max(org_surveylog.actiondate) from org_surveylog 
left join org_division on (org_surveylog.division_code= org_division.division_code and org_surveylog.SURVEY_NUM= org_division.survey_num)
left join org_department on (org_surveylog.department_code = org_department.department_code and org_surveylog.SURVEY_NUM = org_department.survey_num) 
 group by org_surveylog.division_code,org_surveylog.department_code

但下面没问题

 select org_surveylog.division_code as divisionCode,org_surveylog.department_code as departmentCode , max(org_surveylog.actiondate) from org_surveylog 
left join org_division on (org_surveylog.division_code= org_division.division_code and org_surveylog.SURVEY_NUM= org_division.survey_num)
left join org_department on (org_surveylog.department_code = org_department.department_code and org_surveylog.SURVEY_NUM = org_department.survey_num) 
 group by org_surveylog.division_code,org_surveylog.department_code

当我需要显示 org_division.name , org_department.name 的值时，如何使用左连接分组？

【问题讨论】：

标签： sql oracle10g group-by ora-00979

【解决方案1】：

您需要将 GROUP BY 更改为

 group by   org_division.name , 
            org_department.name
            org_surveylog.division_code,
            org_surveylog.department_code

来自Oracle Select Statements : Select Statement With GROUP BY Clause

SELECT <column_name>, <aggregating_operation>
FROM <table_name>
GROUP BY <column_name>;

您会注意到您需要在 GROUP BY 语句中包含非聚合列。

【讨论】：