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SQL Set Operators

SQL Set Operators   Traditional Set Operators: Union Compatibility:     Requirement for the traditional set operators.    Strong requirement.                         - Same number of columns.                         - Each corresponding column is compatible.                         - Positional correspondence.     Apply to similar tables by removing columns first. SQL UNION Example:           Example 1: Retrieve basic data about all university people.                     SELECT FacNo AS PerNo, FacFirstName                                      ...
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Join Operation

Join Operation Using SELECT Statement

 Cross Product Style:

    • List tables in the FROM clause.
    • List join conditions in the WHERE clause.

Example:

        SELECT OfferNo, CourseNo, FacFirstName, FacLastName 
        FROM Offering, Faculty 
        WHERE OffTerm = 'FALL' 
        AND OffYear = 2016 AND FacRank = 'ASST' 
        AND CourseNo LIKE 'IS%' 
        AND Faculty.FacNo = Offering.FacNo;


Join Operator Style:

    • Use INNER JOIN and ON keywords.
    • FROM clause contains join operations.


Example:

        SELECT OfferNo, CourseNo, FacFirstName, FacLastName 
        FROM Offering INNER JOIN Faculty 
        ON Faculty.FacNo = Offering.FacNo 
        WHERE OffTerm = 'FALL' 
        AND OffYear = 2016 
        AND FacRank = 'ASST' 
        AND CourseNo LIKE 'IS%';


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SQL Set Operators

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