NEO4J入门基础第二章

1、简单导入CSV数据

Load CSV读取但不存入数据库：

查看前CSV文件行数

LOAD CSV FROM "file-url" AS line
RETURN count(*);
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查看前CSV文件前5行

LOAD CSV FROM "file-url" AS line WITH line
RETURN line
LIMIT 5;
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1.2 导入CSV时附带表头

LOAD CSV WITH HEADERS FROM "file-url" AS line WITH line
RETURN line
LIMIT 5;

1.3 导入CSV大文件

如果要导入包含大量数据的CSV文件，则可以使用PERODIC COMMIT子句。使用PERODIC COMMIT指示Neo4j在执行完一定行数后提交数据再继续，这样减少了内存开销。使用PERODIC COMMIT默认值为1000行，因此数据将每一千行提交一次。

要使用PERODIC COMMIT，只需在LOAD CSV语句之前插入USING PERIODIC COMMIT语句。

USING PERIODIC COMMIT
LOAD CSV WITH HEADERS FROM 'http://we-yun.com/neo4jguide/movie.csv' AS line
CREATE(:Movie{title:line.title,released:line.released, tagline:line.tagline})

也可以改变默认单次提交行数，如改为800：

USING PERODIC COMMIT 800
LOAD CSV WITH HEADERS FROM 'http://we-yun.com/neo4jguide/tracks.csv' AS line
CREATE (:Track {TrackId:line.Id, Name:line.Track, Length:line.Length})

使用neo4j-import工具导入到neo4j

bin/neo4j-import --into retail.db --id-type string \ --nodes:Customer customers.csv --nodes products.csv \ --nodes orders_header.csv,orders1.csv,orders2.csv \ --relationships:CONTAINS order_details.csv \ --relationships:ORDERED customer_orders_header.csv,orders1.csv,orders2.csv