ArangoDB插入邊緣不存在

Question

我想在docment集合C1和C3之間創建獨特的優勢。
唯一約束是id和kid 。
我使用flow aql來創建它，但是我在同一個id和kid中獲得了多個邊緣。
我怎么能實現它？ 對不起我可憐的英語:)

for i in C1 filter i.id != null and i.id != '' let exist = first( for c in C2 filter i.id == c.id and i.kid == c.kid limit 1 return c ) filter exist == null let result = first( for h in C3 filter i.kid == h.kid limit 1 return h ) insert{_from:i._id, _to:result._id, id:i.id, kid:i.kid} INTO C2

Answer 1

我的英語也不太好^）！ 但我想，我知道你犯了哪些錯誤。 首先，對於您的兩個集合，您可以使用以下代碼：

    LET data = [
    {"parent":{"ID":"YOU_MUST_WRITE_HERE_ID_C1"},"child":{"KID":"YOU_MUST_WRITE_HERE_KID_C3"}},
    {"parent":{"ID":"YOU_MUST_WRITE_HERE_NEXT_ID_C1"},"child":{"KID":"YOU_MUST_WRITE_HERE_NEXT_KID_C3"}}
    ]
FOR rel in data
    LET parentId = FIRST(
        FOR c IN C1
            FILTER c.GUID == rel.parent.ID
            LIMIT 1
            RETURN c._id
    )
    LET childId = FIRST(
        FOR c IN C3
            FILTER c.GUID == rel.child.KID
            LIMIT 1
            RETURN c._id
    )
    FILTER parentId != null AND childId != null
    INSERT { _from: childId, _to: parentId } INTO C2
    RETURN NEW

我希望它對你有所幫助。

第二 - 為什么在這個片段中使用С2集合？

let exist = first(
    for c in C2