基本SQL查询帮助

我为一个School项目创建了几个表。兴趣表是

                //table courses
        CREATE TABLE courses(courseId SERIAL PRIMARY KEY, facultyId REFERENCES faculties(facultyId), courseName TEXT);

                //table weights
    CREATE TABLE weights(weightId SERIAL PRIMARY KEY, weightName TEXT, weight INTEGER);

//table subjects
CREATE TABLE subjects(subjectId SERIAL PRIMARY KEY, subjectName TEXT);
        //table weights_subjects_courses
    CREATE TABLE weights_subjects_courses(courseId integer REFERENCES courses(courseId), weightId integer REFERENCES weights(weightId), subjectId integer REFERENCES subjects(subjectId)

当我尝试下面的查询时，问题出现了

SELECT * FROM courses, subjects, weights WHERE courses.courseId= weights_subjects_courses.courseId AND subjects.subjectId= weights_subjects_courses.subjectId AND weights.weightId= weights_subjects_courses.weightId ORDER BY courseName;

我得到这个错误 SQL错误：

ERROR:  missing FROM-clause entry for table "weights_subjects_courses"
LINE 1: ...ourses, subjects, weights WHERE courses.courseId= weights_su...
                                                             ^

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提前感谢

您的where子句中有权重科目，但from子句中没有权重科目。无论何时在where子句中联接表，都需要将它们包括在from子句中

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所以只需在from子句中添加权重、科目和课程，即可修复该错误

“无论何时在where子句中加入表，都需要将它们包括在from子句中。”谢谢：）任何时候，我想这只是一个疏忽；）