問合せの列名の置換
SELECT文を実行するときに、列に異なる名前を使用できます。問合せ内で名前を置き換えても列名は変更されませんが、返されるデータ内では置換された名前が使用されます。
例: 次の問合せは、結果の
CONTACTATとして電話番号を返します。SELECT contactPhone AS CONTACTAT FROM BaggageInfo説明: 乗客の連絡先電話番号をフェッチして、CONTACTATとして表示する必要があります。
出力:
{"CONTACTAT":"960-428-3843"}
{"CONTACTAT":"368-769-5636"}
{"CONTACTAT":"364-610-4444"}
{"CONTACTAT":"395-837-3772"}
{"CONTACTAT":"893-324-1064"}
{"CONTACTAT":"289-564-3497"}
{"CONTACTAT":"334-679-5105"}
{"CONTACTAT":"978-191-8550"}
{"CONTACTAT":"849-731-1334"}
{"CONTACTAT":"796-709-9501"}
{"CONTACTAT":"539-097-5220"}
{"CONTACTAT":"575-781-6240"}
{"CONTACTAT":"131-183-0560"}
{"CONTACTAT":"619-956-8760"}
{"CONTACTAT":"364-610-4444"}
{"CONTACTAT":"421-272-8082"}
{"CONTACTAT":"567-710-9972"}
{"CONTACTAT":"600-918-8404"}
{"CONTACTAT":"987-210-3029"}
{"CONTACTAT":"666-302-0028"}
{"CONTACTAT":"165-742-5715"}次に示すように、連結演算子||を使用して列を結合できます。
例: すべての顧客について、手荷物が最後に確認された場所と、手荷物が確認された時刻をフェッチします。
アプローチ1: 連結演算子を使用して、SELECTコマンドの出力として列名と静的テキストをフェッチします。
SELECT "The bag was last seen at " ||
bag.bagInfo[].lastSeenStation || " on " ||
bag.bagInfo[].bagArrivalDate AS Bag_Details FROM BaggageInfo bag出力:
{"Bag_Details":"The bag was last seen at BZN on 2019-03-15T10:13:00Z"}
{"Bag_Details":"The bag was last seen at MEL on 2019-02-04T10:08:00Z"}
{"Bag_Details":"The bag was last seen at MEL on 2019-02-25T20:15:00Z"}
{"Bag_Details":"The bag was last seen at MAD on 2019-03-07T13:51:00Z"}
{"Bag_Details":"The bag was last seen at FRA on 2019-03-02T13:18:00Z"}
{"Bag_Details":"The bag was last seen at VIE on 2019-02-12T07:04:00Z"}
{"Bag_Details":"The bag was last seen at JTRJTR on 2019-03-12T15:05:00Z2019-03-12T16:25:00Z"}
{"Bag_Details":"The bag was last seen at JTR on 2019-03-07T16:01:00Z"}
{"Bag_Details":"The bag was last seen at MEL on 2019-02-01T16:13:00Z"}
{"Bag_Details":"The bag was last seen at MXP on 2019-03-22T10:17:00Z"}
{"Bag_Details":"The bag was last seen at MEL on 2019-02-16T16:13:00Z"}
{"Bag_Details":"The bag was last seen at MIA on 2019-03-02T16:09:00Z"}
{"Bag_Details":"The bag was last seen at BZN on 2019-02-21T14:08:00Z"}
{"Bag_Details":"The bag was last seen at SGN on 2019-02-10T10:01:00Z"}
{"Bag_Details":"The bag was last seen at JTR on 2019-02-02T23:59:00Z"}
{"Bag_Details":"The bag was last seen at BLR on 2019-03-14T06:22:00Z"}
{"Bag_Details":"The bag was last seen at VIE on 2019-03-05T12:00:00Z"}
{"Bag_Details":"The bag was last seen at JTR on 2019-03-12T15:05:00Z"}
{"Bag_Details":"The bag was last seen at SEA on 2019-02-15T21:21:00Z"}
{"Bag_Details":"The bag was last seen at HKG on 2019-02-03T08:09:00Z"}
{"Bag_Details":"The bag was last seen at HKG on 2019-02-13T11:15:00Z"}上に示すように、顧客/予約番号ごとに複数の手荷物が存在する場合、結果は複雑になります。
アプローチ2: この問題に対処するには、次に示すように、
bagInfo配列の要素の値として出力します。SELECT "The bag was last seen at " || [bag.bagInfo[].lastSeenStation] || " on " ||
[bag.bagInfo[].bagArrivalDate] AS Bag_Details FROM BaggageInfo bagノート:
列名と静的テキストは、||演算子を使用して連結することもできます。説明: bagInfo JSON内のドキュメントの一部を様々な静的テキストと連結して、配列の要素として表示します。
出力:
{"Bag_Details":"The bag was last seen at [\"MIA\"] on [\"2019-03-02T16:09:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"BZN\"] on [\"2019-02-21T14:08:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"SGN\"] on [\"2019-02-10T10:01:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"HKG\"] on [\"2019-02-13T11:15:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"JTR\"] on [\"2019-02-02T23:59:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"BLR\"] on [\"2019-03-14T06:22:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"VIE\"] on [\"2019-03-05T12:00:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"JTR\"] on [\"2019-03-12T15:05:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"SEA\"] on [\"2019-02-15T21:21:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"HKG\"] on [\"2019-02-03T08:09:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"BZN\"] on [\"2019-03-15T10:13:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"MEL\"] on [\"2019-02-04T10:08:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"MEL\"] on [\"2019-02-25T20:15:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"MAD\"] on [\"2019-03-07T13:51:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"FRA\"] on [\"2019-03-02T13:18:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"VIE\"] on [\"2019-02-12T07:04:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"JTR\",\"JTR\"] on [\"2019-03-12T15:05:00Z\",
\"2019-03-12T16:25:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"JTR\"] on [\"2019-03-07T16:01:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"MEL\"] on [\"2019-02-01T16:13:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"MXP\"] on [\"2019-03-22T10:17:00Z\"]"}
{"Bag_Details":"The bag was last seen at [\"MEL\"] on [\"2019-02-16T16:13:00Z\"]"}