いくつかの重複レコードを持つ2つのMySQLテーブルからデータをクエリする

両方に明確な結果が必要な場合はunionを使用でき、重複した結果が必要な場合はunionallを使用できます

      SELECT CustID
          , DateSubmitted
          , Type
          , Points
              FROM `trans_summary`
                WHERE CustID = '10009'
    UNION

    SELECT CustID
    , DateSubmitted
    , Type
    , PointTotal 
        FROM `ptrans_detail` 
           WHERE CustID = '10009'
                and DateSubmitted NOT IN 
               (SELECT DateSubmitted FROM 
                 `trans_summary` 
                  WHERE CustID = '10009')

または、必要に応じてすべてを結合して結果を複製します

      SELECT CustID
          , DateSubmitted
          , Type
          , Points
              FROM `trans_summary`
                WHERE CustID = '10009'
    UNION ALL 

    SELECT CustID
    , DateSubmitted
    , Type
    , PointTotal 
        FROM `ptrans_detail` 
           WHERE CustID = '10009'
                and DateSubmitted NOT IN 
               (SELECT DateSubmitted FROM 
                 `trans_summary` 
                  WHERE CustID = '10009')