# Neo4j語法
## Match
* 取得全部

MATCH (n) RETURN n

## datebase
* 新增 database

create database [name]

* 切換 database

:use [database name]

## Create
* 新增使用者

CREATE user YOUR_USERNAME SET password 'YOUR_PASSWORD' CHANGE NOT REQUIRED

* 新增節點

CREATE (a:Person {name: 'Alice'})

* 兩個名字的節點中加關係

MATCH (a:Structure {name: 'Speaker'}), (b:Function {name: 'Speaker'})
create (a)-[:has_feature]->(b)

* 兩個id的節點加關係

MATCH (a) 
WHERE id(a) = 123 
MATCH (b) 
WHERE id(b) = 456 
CREATE (a)-[:has_feature]->(b)

## Delete
* 刪除特定label的節點

MATCH (n:YourLabel)
DETACH DELETE n;

* 刪除特定label的關係

MATCH ()-[r:YOUR_RELATIONSHIP_TYPE]->()
DELETE r;

* 刪除特定id的節點

MATCH (n)
WHERE id(n) = 123
DETACH DELETE n;

* 刪除特定id的關係

MATCH ()-[r]->()
WHERE id(r) = 456
DELETE r;

* 刪除特定ids的關係

MATCH ()-[r]->()
WHERE id(r) = 1 OR id(r) = 2 OR id(r) = 3
DELETE r;

或是

MATCH ()-[r]->()
WHERE id(r) IN [1, 2, 3]
DELETE r;

## 更新
* 更新attr by id

MATCH (n) 
WHERE id(n) = 123 
SET n.name = "New Name"
RETURN n