如何使用where子句和内连接

Question

我有以下查询我想使用where子句，但它显示的不是明显的值，请在currentdate后使用多列时帮助我，它不显示不同的值

SELECT CONVERT(VARCHAR(10), ts.current_datetime, 101) AS currentdatets,ts.student_id,tc.class_name,tsi.section_name,tl.test_name FROM tblstudentmarks ts 
INNER JOIN tblclassinfo tc ON
tc.Idx = ts.class_id 
INNER JOIN tblsectioninfo tsi ON
tsi.Idx = ts.section_id 
INNER JOIN tblsubjects su ON
su.Idx = ts.subject_id 
INNER JOIN tbltestlist tl ON
tl.Idx = ts.testtype
WHERE  ts.school_id = 2 AND ts.section_id = 1 AND TS.class_id = 2 AND ts.testtype = 1

Answer 1

您的问题不清楚，但似乎您只需要将DISTINCT添加到选择中...

SELECT DISTINCT
    CONVERT(VARCHAR(10), ts.current_datetime, 101) AS currentdate 
FROM tblstudentmarks ts 
    INNER JOIN tblclassinfo tc ON
    tc.Idx = ts.class_id 
    INNER JOIN tblsectioninfo tsi ON
    tsi.Idx = ts.section_id 
    INNER JOIN tblsubjects su ON
    su.Idx = ts.subject_id 
    INNER JOIN tbltestlist tl ON
    tl.Idx = ts.testtype
WHERE  
    ts.school_id = 2 AND ts.section_id = 1 
    AND TS.class_id = 2 AND ts.testtype = 1