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Use of COUNT in SQL
It describes and discusses various general methods of expressing constraints, eventually noting that support for "=" with relation operands is sufficient for completeness. It also notes that every constraint can be expressed as an invocation of IS_EMPTY, where IS_EMPTY(r) is equivalent to r { } = TABLE_DUM. First, though, it gives Example, showing how to use COUNT to test a relation for emptiness. Example here is a direct translation of that one into SQL.
Example: Testing for absence of counterexamples.
CREATE ASSERTION Must_be_enrolled_to_take_exam
CHECK ((SELECT COUNT (*)
FROM EXAM_MARK
WHERE (Student_Id, CourseId ) NOT IN
(SELECT Student_Id, CourseId
FROM IS_ENROLLED_ON ) )
= 0);
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Application to Export Excel Data to MSSQL Server table I am having a table available in excel format and features the subsequent: - Some text is in Arabic (e.g. UTF-8 encodin
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%ROWCOUNT The %ROWCOUNT yields the number of rows affected by the INSERT, UPDATE, or DELETE statement, or returned by a SELECT INTO statement. The %ROWCOUNT yields zero when a
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Using DELETE This process has three forms. The DELETE removes all elements from the collection. DELETE(n) removes the nth element from the nested table. When n is null, then D
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