数据类型 #

OrientDB数据类型：
├── 基本类型
│   ├── 数值类型
│   ├── 字符串类型
│   ├── 布尔类型
│   └── 日期时间类型
├── 集合类型
│   ├── LIST
│   ├── SET
│   └── MAP
├── 链接类型
│   ├── LINK
│   ├── LINKLIST
│   ├── LINKSET
│   └── LINKMAP
├── 嵌入类型
│   ├── EMBEDDED
│   ├── EMBEDDEDLIST
│   ├── EMBEDDEDSET
│   └── EMBEDDEDMAP
└── 特殊类型
    ├── BINARY
    └── DECIMAL

CREATE CLASS Product
CREATE PROPERTY Product.id INTEGER
CREATE PROPERTY Product.price DECIMAL
CREATE PROPERTY Product.stock LONG
CREATE PROPERTY Product.discount FLOAT

INSERT INTO Product SET 
    id = 1001,
    price = 99.99,
    stock = 10000L,
    discount = 0.15F

SELECT id, price * (1 - discount) AS finalPrice FROM Product
SELECT id, ROUND(price, 2) AS roundedPrice FROM Product

CREATE CLASS Person
CREATE PROPERTY Person.name STRING
CREATE PROPERTY Person.email STRING (NOTNULL, MANDATORY)

INSERT INTO Person SET name = 'Tom Hanks', email = 'tom@example.com'

SELECT 
    name,
    UPPER(name) AS upperName,
    LOWER(name) AS lowerName,
    LENGTH(name) AS nameLength,
    TRIM(name) AS trimmedName,
    SUBSTRING(name, 0, 3) AS shortName
FROM Person

CREATE CLASS User
CREATE PROPERTY User.isActive BOOLEAN
CREATE PROPERTY User.isAdmin BOOLEAN

INSERT INTO User SET name = 'Tom', isActive = true, isAdmin = false

SELECT * FROM User WHERE isActive = true
SELECT * FROM User WHERE NOT isAdmin

CREATE CLASS Event
CREATE PROPERTY Event.eventDate DATE
CREATE PROPERTY Event.createdAt DATETIME

INSERT INTO Event SET 
    name = 'Conference',
    eventDate = DATE('2024-06-15'),
    createdAt = DATETIME('2024-01-15 10:30:00')

SELECT 
    name,
    eventDate,
    YEAR(eventDate) AS year,
    MONTH(eventDate) AS month,
    DAY(eventDate) AS day,
    SYSDATE() AS now
FROM Event

SELECT * FROM Event WHERE eventDate > DATE('2024-01-01')
SELECT * FROM Event WHERE createdAt BETWEEN DATE('2024-01-01') AND DATE('2024-12-31')

CREATE CLASS Person
CREATE PROPERTY Person.hobbies LIST OF STRING

INSERT INTO Person SET name = 'Tom', hobbies = ['reading', 'coding', 'gaming']

SELECT name, hobbies[0] AS firstHobby FROM Person
SELECT name, hobbies FROM Person WHERE 'coding' IN hobbies

UPDATE Person ADD hobbies = 'swimming' WHERE name = 'Tom'
UPDATE Person REMOVE hobbies = 'gaming' WHERE name = 'Tom'
SELECT name, SIZE(hobbies) AS hobbyCount FROM Person

CREATE PROPERTY Person.tags SET OF STRING

INSERT INTO Person SET name = 'Tom', tags = {'developer', 'java', 'python'}

SELECT name, tags FROM Person WHERE 'java' IN tags

UPDATE Person ADD tags = 'javascript' WHERE name = 'Tom'
UPDATE Person REMOVE tags = 'python' WHERE name = 'Tom'

CREATE PROPERTY Person.preferences MAP OF STRING

INSERT INTO Person SET 
    name = 'Tom',
    preferences = {'theme': 'dark', 'language': 'en', 'timezone': 'UTC+8'}

SELECT name, preferences['theme'] AS theme FROM Person

UPDATE Person PUT preferences = 'fontSize', 'large' WHERE name = 'Tom'
UPDATE Person REMOVE preferences['timezone'] WHERE name = 'Tom'

CREATE CLASS Person EXTENDS V
CREATE CLASS Company EXTENDS V
CREATE PROPERTY Person.employer LINK Company

INSERT INTO Company SET name = 'ABC Corp'
INSERT INTO Person SET name = 'Tom', employer = (SELECT FROM Company WHERE name = 'ABC Corp')

SELECT name, employer.name AS companyName FROM Person

LINK特点：
├── 存储目标记录的RID
├── 支持自动解引用
├── 支持双向导航
└── 删除时可选级联

CREATE PROPERTY Person.friends LINKLIST OF Person

UPDATE Person ADD friends = (SELECT FROM Person WHERE name = 'Jerry') WHERE name = 'Tom'

SELECT name, friends.name AS friendNames FROM Person

CREATE PROPERTY Person.followers LINKSET OF Person

UPDATE Person ADD followers = (SELECT FROM Person WHERE name = 'Jerry') WHERE name = 'Tom'

SELECT name, SIZE(followers) AS followerCount FROM Person

CREATE PROPERTY Person.projects LINKMAP OF Project

UPDATE Person PUT projects = 'main', (SELECT FROM Project WHERE name = 'Alpha') WHERE name = 'Tom'

SELECT name, projects['main'].name AS mainProject FROM Person

CREATE CLASS Address
CREATE PROPERTY Address.street STRING
CREATE PROPERTY Address.city STRING
CREATE PROPERTY Address.zipCode STRING

CREATE CLASS Person
CREATE PROPERTY Person.address EMBEDDED Address

INSERT INTO Person SET 
    name = 'Tom',
    address = {'street': 'Main St', 'city': 'Beijing', 'zipCode': '100000'}

SELECT name, address.city FROM Person

CREATE PROPERTY Person.phoneNumbers EMBEDDEDLIST

INSERT INTO Person SET 
    name = 'Tom',
    phoneNumbers = [
        {'type': 'home', 'number': '123-456-7890'},
        {'type': 'work', 'number': '098-765-4321'}
    ]

SELECT name, phoneNumbers[0].number AS homePhone FROM Person

CREATE PROPERTY Person.skills EMBEDDEDSET

INSERT INTO Person SET 
    name = 'Tom',
    skills = {
        {'name': 'Java', 'level': 'expert'},
        {'name': 'Python', 'level': 'intermediate'}
    }

SELECT name, skills FROM Person

CREATE PROPERTY Person.settings EMBEDDEDMAP

INSERT INTO Person SET 
    name = 'Tom',
    settings = {
        'theme': 'dark',
        'language': 'en',
        'notifications': {'email': true, 'sms': false}
    }

SELECT name, settings['theme'] AS theme FROM Person

CREATE CLASS Document
CREATE PROPERTY Document.content BINARY
CREATE PROPERTY Document.fileName STRING
CREATE PROPERTY Document.mimeType STRING

INSERT INTO Document SET 
    fileName = 'report.pdf',
    mimeType = 'application/pdf',
    content = '<binary_data>'

SELECT fileName, LENGTH(content) AS fileSize FROM Document
SELECT FROM Document WHERE mimeType = 'application/pdf'

格式: #<cluster-id>:<cluster-position>

示例:
#12:0  - 第12号集群的第0条记录
#12:1  - 第12号集群的第1条记录

SELECT FROM #12:0
SELECT @rid, name FROM Person
SELECT * FROM Person WHERE @rid = #12:0

SELECT RID(@this) FROM Person
SELECT FROM Person WHERE @rid IN [#12:0, #12:1, #12:2]

SELECT STRING(age) AS ageString FROM Person
SELECT INTEGER('123') + 1 AS result
SELECT DATE('2024-01-15') AS dateValue
SELECT BOOLEAN('true') AS boolValue

SELECT 'Age: ' + age AS label FROM Person
SELECT age + ' years old' AS label FROM Person

NULL特点：
├── 表示缺失或未知值
├── 与任何值比较都为NULL
├── 参与运算结果为NULL
└── 需要特殊处理

SELECT COALESCE(nickname, name, 'Unknown') AS displayName FROM Person
SELECT IFNULL(email, 'N/A') AS emailDisplay FROM Person
SELECT NULLIF(score, 0) AS normalizedScore FROM Exam

SELECT * FROM Person WHERE email IS NULL
SELECT * FROM Person WHERE email IS NOT NULL

CREATE PROPERTY Person.email STRING (NOTNULL)

CREATE PROPERTY Person.name STRING (MANDATORY)

CREATE PROPERTY Person.status STRING DEFAULT 'active'
CREATE PROPERTY Person.createdAt DATETIME DEFAULT sysdate()

CREATE PROPERTY Person.age INTEGER (MIN 0, MAX 150)
CREATE PROPERTY Person.score INTEGER (MIN 0, MAX 100)

CREATE PROPERTY Person.email STRING (REGEXP '^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$')

SELECT name, @class, @type FROM Person
SELECT properties FROM metadata:schema WHERE name = 'Person'

SELECT name, 
    CASE 
        WHEN age IS NULL THEN 'NULL'
        WHEN typeof(age) = 'INTEGER' THEN 'INTEGER'
        ELSE 'OTHER'
    END AS ageType
FROM Person

性能建议：
├── 使用最小够用的类型
├── EMBEDDED适合频繁一起读取的数据
├── LINK适合独立更新的数据
├── SET比LIST更适合去重场景
└── 避免过深的嵌套结构

存储优化：
├── 使用合适的数值类型
├── 压缩长字符串
├── 合理使用EMBEDDED减少JOIN
└── 避免存储冗余数据