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44
offeringid SERIAL PRIMARY KEY NOT NULL,
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45
subject INT4 REFERENCES subject (subjectid) NOT NULL,
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46
semesterid INTEGER REFERENCES semester (semesterid) NOT NULL,
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49
groups_student_permissions VARCHAR NOT NULL DEFAULT 'none',
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CHECK (groups_student_permissions in ('none', 'invite', 'create')),
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UNIQUE (subject, semesterid)