我怎样才能使这个select语句

第一个

SELECT 
    course.CourseNum, 
    course.CourseName, 
    course.CreditHours 
FROM course 
WHERE course.TypeID=1

结果是

Course Num------Course Name---------Credit Hours          
1101----------Arabic Language----------3    
1103----------English LanguageI--------3    
1104----------English LanguageII-------3    
1106----------Hebrew LanguageI---------3    
1125----------Scientific Research------3

第二个是只显示有

等级结果

SELECT 
    course.CourseNum, 
    course.CourseName, 
    course.CreditHours, 
    studentcoursecomplete.CourseGrade 
FROM course, studentcoursecomplete 
WHERE studentcoursecomplete.SID=1 
    And studentcoursecomplete.CourseID = course.CourseID 
    AND course.TypeID=1

r结果是

Course Num---------Course Name----------Credit Hours-----Grade    
1101---------------Arabic Language-----------3------------60  
1103---------------English LanguageI---------3------------65   
1104---------------English LanguageII--------3------------70

所以现在我需要一个SQL语句，显示第一个记录，除了第二个记录！ sql语句必须显示此结果。

Course Num------Course Name---------Credit Hours     
1106----------Hebrew LanguageI---------3          
1125----------Scientific Research------3

来源

2014-09-03 Gabriel Blanco

您应该了解有关连接：http://blog.codinghorror.com/a-visual-explanation-of-sql-joins/了解那些会回答您的问题。 – 2014-09-03 17:06:59

因此，您正在寻找所有不在“已完成”桶中的课程？ – 2014-09-03 17:22:17

你可以做一个左连接，查找NULL。尽可能使用表别名，以使代码更具可读性。

select 
    c.CourseNum, 
    c.CourseName, 
    c.CreditHours 
from course c 
left join studentcoursecomplete cc 
    on cc.CourseID = c.CourseID 
    and cc.SID = 1 
where c.TypeID=1 
    and cc.CourseID is null

来源

2014-09-03 17:24:55

你提到了LEFT-JOIN，但是把你的样本留作JOIN。 – DRapp 2014-09-03 17:26:36

试试这个代码。它应该给你想要的结果。

SELECT course.CourseNum, course.CourseName, course.CreditHours 
FROM course course left join 
studentcoursecomplete studentcoursecomplete on 
studentcoursecomplete.CourseID = course.CourseID and studentcoursecomplete.SID=1 
where studentcoursecomplete.CourseID is null 
and course.TypeID=1;

来源

2014-09-03 17:11:37

SELECT course.CourseNum, course.CourseName, course.CreditHours 
FROM course 
WHERE course.TypeID=1 
MINUS 
SELECT course.CourseNum, course.CourseName,course.CreditHours,studentcoursecomplete.CourseGrade 
FROM course,studentcoursecomplete 
WHERE studentcoursecomplete.SID=1 And studentcoursecomplete.CourseID = course.CourseID AND course.TypeID=1;

试试这个:)

来源

2014-09-03 17:12:50 WisdmLabs

我怎样才能使这个select语句

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