Question

我希望使用基于SQL Server数据库中的2个表的条件检索非重复数据。

表主题

ID       NAME                                       COURSE
-------  -----------------------------------------  ---------------------------------
SUB1234  SOFTWARE QUALITY AND PROCESS MANAGEMENT    AUPAS AMERICAN UNIVERSITY PROGRAM
SUB2234  SOFTWARE QUALITY AND PROCESS MANAGEMENT 1  AUPAS AMERICAN UNIVERSITY PROGRAM
SUB3234  SOFTWARE QUALITY AND PROCESS MANAGEMENT 2  AUPAS AMERICAN UNIVERSITY PROGRAM

表格结果

ID       SUBJECT  RESULT
-------  -------  ------
STU0001  SUB1234  NULL

期望的输出：

当ID = STU0001且课程= AUPAS美国大学课程时，从主题表中获取SUB2234和SUB3234。

使用下面的查询，我只能检索非重复数据。

SELECT SUB.ID, SUB.NAME
FROM SUBJECT SUB LEFT JOIN
     RESULT RES
     ON RES.SUBJECT = SUB.ID
WHERE RES.SUBJECT IS NULL;

Answer 1

此查询获得所需的结果。

SELECT SUB.ID, SUB.NAME
  FROM SUBJECT SUB 
 WHERE NOT EXISTS (SELECT 1 
                     FROM RESULT RES
                    WHERE RES.ID = 'STU0001'
                      AND RES.SUBJECT = SUB.ID)
   AND SUB.COURSE = 'AUPAS AMERICAN UNIVERSITY PROGRAM';

基本上，查询获得课程='AUPAS AMERICAN UNIVERSITY PROGRAM'的所有科目，并排除学生已经关联的科目。

希望这有帮助！

Answer 2

认为这就是你所追求的目标

select res.id as student, sub.id as 'subject'
from @result res, @subject sub
where sub.id != res.subj

使用条件检索非重复数据

2 个答案: