前言：
這篇文章通過 NorthWind Graph 的例子熟悉並掌握 neo4j 導入 CSV 文件。
一、環境配置
在導入之前確保 neo4j.conf 中允許 CSV 導入。
打開 neo4j.conf: $ vim neo4j.conf
修改 dbms.security.allow_csv_import_from_file_urls=true
二、數據准備
- products.csv (http://data.neo4j.com/northwind/products.csv)
- categories.csv (http://data.neo4j.com/northwind/categories.csv)
- suppliers.csv (http://data.neo4j.com/northwind/suppliers.csv)
- customers.csv(http://data.neo4j.com/northwind/customers.csv)
- orders.csv (http://data.neo4j.com/northwind/orders.csv)
- order-details.csv (http://data.neo4j.com/northwind/order-details.csv)
注意：從本地導入 CSV 文件時，需要將文件放在 import 文件夾下！
三、數據導入（本地）
1. 導入 products.csv
//load products.csv LOAD CSV WITH HEADERS FROM "file:///northwind/products.csv" AS row CREATE (n:Product) SET n = row, n.unitPrice = toFloat(row.unitPrice), n.unitsInStock = toInteger(row.unitsInStock), n.unitsOnOrder = toInteger(row.unitsOnOrder), n.reorderLevel = toInteger(row.reorderLevel), n.discontinued = (row.discontinued <> "0")
2.導入 categories.csv
//load categories.csv LOAD CSV WITH HEADERS FROM "file:///northwind/categories.csv" AS row CREATE (n:Category) SET n = row
3. 導入 suppliers.csv
//load suppliers.csv LOAD CSV WITH HEADERS FROM "file:///northwind/suppliers.csv" AS row CREATE (n:Supplier) SET n = row
4. 為產品等實體創建索引
給三類實體分別創建索引，方便后期提高查詢效率。
//create indexes CREATE INDEX ON :Product(productID) CREATE INDEX ON :Category(categoryID) CREATE INDEX ON :Supplier(supplierID)
5. 為產品等實體建立聯系
為這三類實體建立聯系，通過相同的 id 作為連接。
MATCH (p:Product),(c:Category) WHERE p.categoryID = c.categoryID CREATE (p)-[:PART_OF]->(c)
商品和種類通過 categoryID 建立了聯系
MATCH (p:Product),(s:Supplier) WHERE p.supplierID = s.supplierID CREATE (s)-[:SUPPLIES]->(p)
商品和供應商通過 supplierID 建立了聯系
6. 列出每個供應商提供的產品類別
MATCH (s:Supplier)-->(:Product)-->(c:Category) RETURN s.companyName as Company, collect(distinct c.categoryName) as Categories
每個食品供應商提供的產品種類表
7. 查找提供海產品("Seafood")的供應商
MATCH (c:Category {categoryName:"Seafood"})<--(:Product)<--(s:Supplier) RETURN DISTINCT s.companyName as ProduceSuppliers
8. 加載 customer.csv
LOAD CSV WITH HEADERS FROM "http://data.neo4j.com/northwind/orders.csv" AS row CREATE (n:Order) SET n = row
9. 加載 order.csv
//load orders.csv LOAD CSV WITH HEADERS FROM "file:///northwind/orders.csv" AS row CREATE (n:Order) SET n = row
10. 為訂單等實體創建索引
//create indexes for customer and order CREATE INDEX ON :Customer(customerID) CREATE INDEX ON :Order(orderID)
11. 為訂單等實體創建關系
//create relationships MATCH (c:Customer),(o:Order) WHERE c.customerID = o.customerID CREATE (c)-[:PURCHASED]->(o)
12. 加載 order-details.csv
//load order-details.csv LOAD CSV WITH HEADERS FROM "file:///northwind/order-details.csv" AS row MATCH (p:Product), (o:Order) WHERE p.productID = row.productID AND o.orderID = row.orderID CREATE (o)-[details:ORDERS]->(p) SET details = row, details.quantity = toInteger(row.quantity)
四、數據查詢
1. 列出訂購了海產品(Seafood)的客戶以及采購量
MATCH (cust:Customer)-[:PURCHASED]->(:Order)-[o:ORDERS]->(p:Product), (p)-[:PART_OF]->(c:Category {categoryName:"Seafood"}) RETURN DISTINCT cust.contactName as CustomerName, SUM(o.quantity) as TotalProductsPurchased
2. 列出 "Thomas Hardy" 訂購的產品及種類
match (cust:Customer{contactName:"Thomas Hardy"})-[:PURCHASED]->(:Order)-[ORDERS]->(p:Product), (p)-[:PART_OF]->(c:Category) return p.productName as Product , c.categoryName as Category
