ArangoDB - 如何通過數組元素的子串查找元素的集合？

Question

沒有與此結構的集合：

{ 
   "user": 1, 
   "timestamp": 216354113151, 
   "message": "asddsaasddsaa", 
   "data": [ 
     "name = Jack & hash = s5w464t35w145df13s5df4sdg & id = 2" 
     "name = Mansonack & hash = xga5fd7h68745v46ed2 & id = 18" 
   ] 
} 

我需要找到這個集合的元素，在關鍵數據有一個包含包含子xga5fd7h68745v46ed2

我可以寫一個字符串值這個查詢？它會是什麼樣子？

Answer 1

你也可以遍歷數組的項目，如在任何其他列表：

FOR d IN collection_name 
FILTER IS_LIST(d.data) 
FOR data IN d.data 
FILTER CONTAINS(data, "xga5fd7h68745v46ed2") 
RETURN d 

Answer 2

如果你的數據數組的子串，你正在尋找，並希望只返回包含搜索值的唯一文檔的多個occurances，然後使用這樣的查詢：

// what you are looking for in string 
LET searchValue = 'xga5fd7h68745v46ed2' 
// go through items of your collection 
FOR item IN collection_name 
    // store result of subquery in temporary variable 
    LET wasItemFound = FIRST((
     // go through elements of your data array 
     FOR str IN item.data 
      // search for desired value within the element 
      FILTER CONTAINS(str, searchValue) 
      // we need to find only single occurance of searchValue 
      LIMIT 1 
      // return true if it was found 
      RETURN true 
    )) 
    // give me only items which contained value you searched for 
    FILTER wasItemFound == true 
    RETURN item 

查詢其pluma建議可能會爲你的用例做的工作，如果你正在尋找的值都爲所有的數據數組元素的獨特。如果在數據數組元素中搜索到多個子字符串，則查詢將返回重複的文檔。例如，考慮這個例子中數據集：

[ 
    { 
    "user": 1, 
    "data": [ 
     "name = Jack & hash = abc & id = 2", 
     "name = Mansonack & hash = abcd & id = 18" 
    ] 
    }, 
    { 
    "user": 2, 
    "data": [ 
     "name = Jack & hash = abb & id = 2", 
     "name = Mansonack & hash = abc & id = 18", 
     "name = xxx& hash = aaa & id = 18" 
    ] 
    } 
] 

如果您使用此查詢

FOR d IN collection_name 
    FILTER IS_LIST(d.data) 
    FOR data IN d.data 
     FILTER CONTAINS(data, "ab") 
     RETURN d 

它將返回4號文件，即使集合只包含2但是，在這個職位的第一個查詢只會返回2.要明確我並不是說pluma的解決方案是錯誤的，而僅僅取決於你期望得到的結果。