Arango db 快速入门
Posted 一只猪的思考
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本文通过以下文章概述而来
https://www.arangodb.com/docs/stable/aql/tutorial.html
一.ArangoDB和传统数据库的区别
二.AQL数据结构
每个文档都需要一个唯一的_key，该_key在集合中标识它。_id是一个计算的属性，是集合名称的串联，一个collection name/和key。它唯一标识数据库中的文档。_rev是由系统管理的修订ID。
"_key": "2861650",
"_id": "Characters/2861650",
"_rev": "_V1bzsXa---",
"name": "Ned",
"surname": "Stark",
"alive": true,
"age": 41,
"traits": ["A","H","C","N","P"]
,
三.crud操作
1. 查询
我们可以在AQL函数DOCUMENT()的帮助下使用文档密钥或文档ID检索特定文档
如：
RETURN DOCUMENT("Characters", "2861650")
// --- or ---
RETURN DOCUMENT("Characters/2861650")
2. 增加操作
INSERT document INTO collectionName
示例：
INSERT
"name": "Ned",
"surname": "Stark",
"alive": true,
"age": 41,
"traits": ["A","H","C","N","P"]
INTO Characters
- 用let定义批量数据
LET variableName = valueExpression
数据存放方式[ …, …, … ]
LET data = [
"name": "Robert", "surname": "Baratheon", "alive": false, "traits": ["A","H","C"] ,
"name": "Jaime", "surname": "Lannister", "alive": true, "age": 36, "traits": ["A","F","B"] ,
"name": "Catelyn", "surname": "Stark", "alive": false, "age": 40, "traits": ["D","H","C"] ,
"name": "Cersei", "surname": "Lannister", "alive": true, "age": 36, "traits": ["H","E","F"] ,
"name": "Daenerys", "surname": "Targaryen", "alive": true, "age": 16, "traits": ["D","H","C"] ,
"name": "Jorah", "surname": "Mormont", "alive": false, "traits": ["A","B","C","F"] ,
"name": "Petyr", "surname": "Baelish", "alive": false, "traits": ["E","G","F"] ,
"name": "Viserys", "surname": "Targaryen", "alive": false, "traits": ["O","L","N"] ,
"name": "Jon", "surname": "Snow", "alive": true, "age": 16, "traits": ["A","B","C","F"] ,
"name": "Sansa", "surname": "Stark", "alive": true, "age": 13, "traits": ["D","I","J"] ,
"name": "Arya", "surname": "Stark", "alive": true, "age": 11, "traits": ["C","K","L"] ,
"name": "Robb", "surname": "Stark", "alive": false, "traits": ["A","B","C","K"] ,
"name": "Theon", "surname": "Greyjoy", "alive": true, "age": 16, "traits": ["E","R","K"] ,
"name": "Bran", "surname": "Stark", "alive": true, "age": 10, "traits": ["L","J"] ,
"name": "Joffrey", "surname": "Baratheon", "alive": false, "age": 19, "traits": ["I","L","O"] ,
"name": "Sandor", "surname": "Clegane", "alive": true, "traits": ["A","P","K","F"] ,
"name": "Tyrion", "surname": "Lannister", "alive": true, "age": 32, "traits": ["F","K","M","N"] ,
"name": "Khal", "surname": "Drogo", "alive": false, "traits": ["A","C","O","P"] ,
"name": "Tywin", "surname": "Lannister", "alive": false, "traits": ["O","M","H","F"] ,
"name": "Davos", "surname": "Seaworth", "alive": true, "age": 49, "traits": ["C","K","P","F"] ,
"name": "Samwell", "surname": "Tarly", "alive": true, "age": 17, "traits": ["C","L","I"] ,
"name": "Stannis", "surname": "Baratheon", "alive": false, "traits": ["H","O","P","M"] ,
"name": "Melisandre", "alive": true, "traits": ["G","E","H"] ,
"name": "Margaery", "surname": "Tyrell", "alive": false, "traits": ["M","D","B"] ,
"name": "Jeor", "surname": "Mormont", "alive": false, "traits": ["C","H","M","P"] ,
"name": "Bronn", "alive": true, "traits": ["K","E","C"] ,
"name": "Varys", "alive": true, "traits": ["M","F","N","E"] ,
"name": "Shae", "alive": false, "traits": ["M","D","G"] ,
"name": "Talisa", "surname": "Maegyr", "alive": false, "traits": ["D","C","B"] ,
"name": "Gendry", "alive": false, "traits": ["K","C","A"] ,
"name": "Ygritte", "alive": false, "traits": ["A","P","K"] ,
"name": "Tormund", "surname": "Giantsbane", "alive": true, "traits": ["C","P","A","I"] ,
"name": "Gilly", "alive": true, "traits": ["L","J"] ,
"name": "Brienne", "surname": "Tarth", "alive": true, "age": 32, "traits": ["P","C","A","K"] ,
"name": "Ramsay", "surname": "Bolton", "alive": true, "traits": ["E","O","G","A"] ,
"name": "Ellaria", "surname": "Sand", "alive": true, "traits": ["P","O","A","E"] ,
"name": "Daario", "surname": "Naharis", "alive": true, "traits": ["K","P","A"] ,
"name": "Missandei", "alive": true, "traits": ["D","L","C","M"] ,
"name": "Tommen", "surname": "Baratheon", "alive": true, "traits": ["I","L","B"] ,
"name": "Jaqen", "surname": "H'ghar", "alive": true, "traits": ["H","F","K"] ,
"name": "Roose", "surname": "Bolton", "alive": true, "traits": ["H","E","F","A"] ,
"name": "The High Sparrow", "alive": true, "traits": ["H","M","F","O"]
]
FOR d IN data
INSERT d INTO Characters
- 循环遍历语法
FOR variableName IN collectionName
例：遍历character中的数据
FOR c IN Characters
RETURN c
3.更新操作
UPDATE documentKey WITH object IN collectionName
例
UPDATE "2861650" WITH alive: false IN Characters
也可使用循环操作
FOR c IN Characters
UPDATE c WITH season: 1 IN Characters
如需更新所有内容可使用replace操作
REPLACE "2861650" WITH
name: "Ned",
surname: "Stark",
alive: false,
age: 41,
traits: ["A","H","C","N","P"]
IN Characters
4. 删除操作
REMOVE documentKey IN collectionName
- 返回数据
FOR c IN Characters
RETURN c
- 等于匹配
FOR c IN Characters
FILTER c.name == "Ned"
RETURN c
四.匹配查询
- 单个匹配
FOR c IN Characters
FILTER c.age >= 13
RETURN c.name
- 多个匹配
FOR c IN Characters
FILTER c.age < 13 AND c.age != null
RETURN name: c.name, age: c.age
- 替代匹配
FOR c IN Characters
FILTER c.name == "Jon" OR c.name == "Joffrey"
RETURN name: c.name, surname: c.surname
五. 排序和限制查询
- 限制查询
返回5个数据
FOR c IN Characters
LIMIT 5
RETURN c.name
跳过一定数量的记录并返回接下来的n个数据
FOR c IN Characters
LIMIT 2, 5
RETURN c.name
- 排序
例：对名称进行排序
FOR c IN Characters
SORT c.name
LIMIT 10
RETURN c.name
在被排序参数后加desc即可降序排列
当然也可以进行多参数排序
例：对surname升序，对name降序
FOR c IN Characters
FILTER c.surname
SORT c.surname, c.name DESC
LIMIT 10
RETURN
surname: c.surname,
name: c.name
六. 联合查询
对于如下示例，我们的traits数组中的每一个字母对应一个trait
"name": "Ned",
"surname": "Stark",
"alive": false,
"age": 41,
"traits": ["A","H","C","N","P"]
将具体traits插入
let data = [
"_key": "A", "en": "strong", "de": "stark" ,
"_key": "B", "en": "polite", "de": "freundlich" ,
"_key": "C", "en": "loyal", "de": "loyal" ,
"_key": "D", "en": "beautiful", "de": "schön" ,
"_key": "E", "en": "sneaky", "de": "hinterlistig" ,
"_key": "F", "en": "experienced", "de": "erfahren" ,
"_key": "G", "en": "corrupt", "de": "korrupt" ,
"_key": "H", "en": "powerful", "de": "einflussreich" ,
"_key": "I", "en": "naive", "de": "naiv" ,
"_key": "J", "en": "unmarried", "de": "unverheiratet" ,
"_key": "K", "en": "skillful", "de": "geschickt" ,
"_key": "L", "en": "young", "de": "jung" ,
"_key": "M", "en": "smart", "de": "klug" ,
"_key": "N", "en": "rational", "de": "rational" ,
"_key": "O", "en": "ruthless", "de": "skrupellos" ,
"_key": "P", "en": "brave", "de": "mutig" ,
"_key": "Q", "en": "mighty", "de": "mächtig" ,
"_key": "R", "en": "weak", "de": "schwach"
]
FOR d IN data
INSERT d INTO Traits
如需将一下数据合并到上文中
FOR c IN Characters
RETURN DOCUMENT("Traits", c.traits)[*].en
[
[
"strong",
"powerful",
"loyal",
"rational",
"brave"
],
[
"beautiful",
"powerful",
"loyal"
],
...
]
可以使用如下merge方法
FOR c IN Characters
RETURN MERGE(c, traits: DOCUMENT("Traits", c.traits)[*].en )
[
"_id": "Characters/2861650",
"_key": "2861650",
"_rev": "_V1bzsXa---",
"age": 41,
"alive": false,
"name": "Ned",
"surname": "Stark",
"traits": [
"strong",
"powerful",
"loyal",
"rational",
"brave"
]
,
"_id": "Characters/2861653",
"_key": "2861653",
"_rev": "_V1bzsXa--B",
"age": 40,
"alive": false,
"name": "Catelyn",
"surname": "Stark",
"traits": [
"beautiful",
"powerful",
"loyal"
]
,
...
]
MERGE()函数将对象合并在一起。由于我们使用了与原始字符属性具有相同属性名称traits的对象traits: ...，后者被合并操作覆盖。
注：
DOCUMENT()函数使用主索引快速查找文档。然而，它仅限于通过其标识符查找
文件
- 便捷方法
FOR c IN Characters
RETURN MERGE(c,
traits: (
FOR key IN c.traits
FOR t IN Traits
FILTER t._key == key
RETURN t.en
)
)
七. 对节点的边生成以及遍历
父和子之间的关系可以建模为图表。在ArangoDB中，两个文档（父Document和子Document）可以通过边缘Document链接。用Edge Document存储边集合，并有两个额外的属性：_from和_to。他们通过Document ID（_id）引用任何两个Document
构建边关系示例
LET data = [
"parent": "name": "Ned", 以上是关于Arango db 快速入门的主要内容，如果未能解决你的问题，请参考以下文章