Cloudantは、すべての最後の値を数えるためにビューを作成します。配列フィールド

Question

多くのjsonドキュメントがCloudantデータベースに格納されています。文書の構造：

{ 
    "_id": "00229e31d5751d337abf409a4bd75492", 
    "_rev": "1-d95d7ad32264d233453a0436b1557e7d", 
    "timestamp": "2017-07-04T21:28:46.886Z", 
    "APIresponse": { 
    "intents": [ 
     { 
     "intent": "greetings", 
     "confidence": 1 
     }, 
     { 
     "intent": "machineBusy", 
     "confidence": 0 
     }, 
     { 
     "intent": "set_weights", 
     "confidence": 0 
     }, 
     { 
     "intent": "faqGuidelinesPAAmount", 
     "confidence": 0 
     }, 
     { 
     "intent": "chat", 
     "confidence": 0 
     }, 
     { 
     "intent": "feedback-no", 
     "confidence": 0 
     }, 
     { 
     "intent": "faqGuidelinesWhatsnew", 
     "confidence": 0 
     }, 
     { 
     "intent": "faqGuidelinesChildren", 
     "confidence": 0 
     }, 
     { 
     "intent": "thanks", 
     "confidence": 0 
     }, 
     { 
     "intent": "faqGuidelinesPAvsFederal", 
     "confidence": 0 
     } 
    ], 
    "entities": [], 
    "input": { 
     "text": "hey" 
    }, 
    "output": { 
     "text": [ 
     "Hey there!", 
     "How a beautiful day to train :) Do you agree #firstName?" 
     ], 
     "nodes_visited": [ 
     "Greetings", 
     "Initial greetings", 
     "node_2_1495711348295" 
     ], 
     "error": "SpelEvaluationException when evaluating DialogNode Id [check PROFILING interrupted ASPFINDER]. Condition [$trainingContext.status == \"no_tp\" && $aspFinder.dob != null || $aspFinder.height != null || $aspFinder.weight != null || $aspFinder.impedIsPresent != null || $aspFinder.goal != null || $aspFinder.timesAWeek != null || $aspFinder.duration != null || $aspFinder.location != null || $aspFinder.level != null || $userContext.height != null] evaluated to FALSE.\norg.springframework.expression.spel.SpelEvaluationException: EL1007E: Property or field 'weight' cannot be found on null\n", 
     "log_messages": [ 
     { 
      "level": "err", 
      "msg": "SpelEvaluationException when evaluating DialogNode Id [check PROFILING interrupted ASPFINDER]. Condition [$trainingContext.status == \"no_tp\" && $aspFinder.dob != null || $aspFinder.height != null || $aspFinder.weight != null || $aspFinder.impedIsPresent != null || $aspFinder.goal != null || $aspFinder.timesAWeek != null || $aspFinder.duration != null || $aspFinder.location != null || $aspFinder.level != null || $userContext.height != null] evaluated to FALSE.\norg.springframework.expression.spel.SpelEvaluationException: EL1007E: Property or field 'weight' cannot be found on null\n" 
     } 
     ] 
    }, 
    "context": { 
     "system": { 
     "dialog_stack": [ 
      { 
      "dialog_node": "node_2_1495711348295" 
      } 
     ], 
     "dialog_request_counter": 5, 
     "dialog_turn_counter": 5, 
     "_node_output_map": { 
      "node_3_1495711396477": [ 
      0 
      ], 
      "node_1_1495037449418": [ 
      0, 
      0, 
      1 
      ], 
      "node_12_1494424156763": [ 
      0, 
      3, 
      0, 
      1, 
      2, 
      4 
      ], 
      "in exercise": [ 
      0 
      ], 
      "Workout Feedback": [ 
      0, 
      2, 
      1, 
      0, 
      3 
      ], 
      "Greetings": [ 
      0 
      ], 
      "node_2_1495711348295": [ 
      0, 
      2, 
      1, 
      0 
      ] 
     } 
     }, 
     "repeat": false, 
     "lastMsg": [ 
     "Great job!", 
     "We're done for today training! Great job :)" 
     ], 
     "conversation_id": "919d2d6b-e085-4fbe-bd12-19486aa0394e", 
     "last": { 
     "trainingContext": { 
      "status": "no_workout", 
      "suggested_workout_id": "W-fb2038d7d45a48a6af844a53f52a1759-T-74e57d317b9649feb5f024c049766fd7-F-technogym" 
     }, 
     "notify_ui": "workout_closed", 
     "output": { 
      "nodes_visited": [ 
      "node_9_1494423774989", 
      "node_1_1494427286758", 
      "node_12_1494424156763" 
      ], 
      "text": [ 
      "Great job!", 
      "We're done for today training! Great job :)" 
      ], 
      "log_messages": [] 
     } 
     }, 
     "_currentSession": { 
     "current_exe": 7 
     }, 
     "currentSession": { 
     "feedback": 5 
     }, 
     "_timestamp": "2017-07-04T21:28:46.561Z", 
     "trainingContext": { 
     "status": "no_workout", 
     "suggested_workout_id": "W-fb2038d7d45a48a6af844a53f52a1759-T-74e57d317b9649feb5f024c049766fd7-F-technogym" 
     }, 
     "userContext": { 
     "height": 160, 
     "userID": "e37e39f4-61ba-41da-a356-2c6cbfae8392", 
     "lastName": "#lastName", 
     "facilityId": "4419597c-b63e-4358-b8ba-cc388bb192c3", 
     "weight": 56, 
     "userToken": "MjAxNzA3MDQyMTI4MzR8MzQyYzJkZmEyNGVkNGZlZDhiOWU5NDg0NWE1YzAxNTJ8ZWMxZDM4ZDdkMzU5NDhkMGE2MGNkOGMwYjhmYjlkZjl8MXxXLiBFdXJvcGUgU3RhbmRhcmQgVGltZXxpdC1JVHxlMzdlMzlmNDYxYmE0MWRhYTM1NjJjNmNiZmFlODM5Mnx8fHwxfDF8MHwxMDB8fHw1OHw2ODk0fDB8Y29tLm15d2VsbG5lc3M1.BC8BBB1E2066444DEA5F5E1F42627CF6443F3077", 
     "firstName": "#firstName", 
     "dob": "03/07/1986" 
     } 
    } 
    } 
} 

値ODFは、私が興味JSONは常に配列フィールドAPIresponse.outout.nodes_visitedで最後です。具体的には、配列フィールドAPIresponse.outout.nodes_visitedの最後の値のカウントと、そのカウント（カウントの名前）に関連付けられた関連値を取得する構造を持っています。

私は通常、Cloudantをクエリするためにセレクタを使用しますが、それは私が探している特定のカウントを取得する方法を提供していないようです。

デザインドキュメントでmap reduce関数を作成しようとしましたが、成功できませんでした。

その後の質問は以下のとおりです。

1. 私はCloudantで配列フィールドの最後の要素にアクセスするにはどうすればよいですか？
2. データベースの配列の最後の要素の合計数はどのようにして取得できますか？

あなたがマップ減らすビューでこれを行うことができます

フィリッポ

Answer 1

、任意の助けてくれてありがとう。まず、1の値を持つ配列からのフィールドを持つキーあなたのEMIT：

function(doc) { 
    if (doc && doc.APIresponse && 
     doc.APIresponse.output && doc.APIresponse.output.nodes_visited){ 
     var arr = doc.APIresponse.output.nodes_visited; 
     emit(arr[arr.length-1], 1); 
    } 
} 

とビルトイン_countを選ぶには、機能を減らします。

curl 'https://USER:PASS@ACCOUNT.cloudant.com/DB/_design/DDOC/_view/VIEWNAME?group=true' 

のようなものを使用して合計であなたはあなたの例のデータは、私のデータベースのいずれかにロードされ見ることができますあなたは今、すべてのノードが訪問した見ることができるはず：

https://skruger.cloudant.com/testdb - それはオープンです読書のために。

私が上記提案ビュー機能を入れ、ここにクエリです：

curl 'https://skruger.cloudant.com/testdb/_design/ddoc/_view/nodes?group=true' 
{"rows":[ 
    {"key":"ask exercise feedback","value":1}, 
    {"key":"Assign workout","value":2}, 
    {"key":"Capabilities","value":1}, 
    {"key":"Feedback_tester","value":1}, 
    {"key":"First Exercise","value":2}, 
    {"key":"mark exercise done","value":1}, 
    {"key":"no_tp","value":8}, 
    {"key":"node_1_1495716162431","value":10}, 
    {"key":"node_2_1495711348295","value":1}, 
    {"key":"node_21_1494245522737","value":1}, 
    {"key":"node_26_1494249967653","value":1}, 
    {"key":"node_3_1495716340965","value":2}, 
    {"key":"node_3_1495922533369","value":2}, 
    {"key":"node_4_1494233636522","value":2}, 
    {"key":"node_6_1493835340035","value":1}, 
    {"key":"node_7_1493835487968","value":1}, 
    {"key":"node_8_1492030091650","value":1}, 
    {"key":"node_8_1494235961152","value":2}, 
    {"key":"node_9_1495711958382","value":1}, 
    {"key":"pr exit service fail","value":7}, 
    {"key":"profiling - ending","value":8}, 
    {"key":"profiling - question duration","value":7}, 
    {"key":"profiling - question goal","value":7}, 
    {"key":"profiling - question impediments","value":7}, 
    {"key":"profiling - question level","value":7}, 
    {"key":"profiling - question location","value":7}, 
    {"key":"profiling - question timesWeek","value":7}, 
    {"key":"show next exercise","value":2} 
]}