Neo4J-有沒有辦法在一個查詢中加載多個子查詢，如LOAD...CREATE..LOAD..CREATE..LOAD...（用于測驗）

所以我正在嘗試獲取一個默認的通用資料庫表。在 MySQL 中，我可以洗掉整個資料庫并運行我的代碼以再次生成默認資料庫。例如 MySQL 的唯一檔案 -> wwfsaew.sql

DROP DATABASE IF EXISTS wwfsaew;
CREATE DATABASE IF NOT EXISTS wwfsaew;

CREATE TABLE Flughafen (...)
...
INSERT INTO Flughafen (...)
...
UPDATE Flughafen SET ...
...
CREATE VIEW ...
...
CREATE PROCEDURE ...
...

但是在 Neo4J 中同樣的方法不起作用。我總是收到錯誤訊息：“Neo.TransientError.General.OutOfMemoryError”

LOAD CSV WITH HEADERS FROM
'file:///C:/Users/Enes/CSV_import/ingredients.csv'
    AS a
LOAD CSV WITH HEADERS FROM 
'file:///C:/Users/Enes/CSV_import/users.csv'
    AS b FIELDTERMINATOR ';'
        LOAD CSV WITH HEADERS FROM 
'file:///C:/Users/Enes/CSV_import/recipes.csv'
    AS c FIELDTERMINATOR ';'

CREATE (ing:ingredients{name:a.ingredientName,
    ingredientName:a.ingredientName})
CREATE (use:users{
    name:b.userName,
    userName:b.userName,
    userEmail:b.userEmail,
    userPassword:b.userPassword,
    enabled:b.enabled})
CREATE (rec:recipe{
    name:c.recipeName,
    recipeName:c.recipeName,
    prepTimeInMin: c.prepTimeInMin,
    restTimeInMinutes: c.restTimeInMinutes,
    prepText: c.prepText,
    people: c.people,
    viewCount: c.viewCount,
    difficultyName: c.difficultyName,
    mealTypeName: c.mealTimeName,
    createdByUser: c.createdByUser})

我不知道為什么它不能這樣作業，因為它自己的每個子查詢都是~20ms。我試過了，USING PERIODIC COMMIT 250但它拋出了一個語意錯誤，因為它是一個顯式事務而不是隱式事務。所以我的問題是：我怎樣才能只獲得一個 .cypher 或 .csv 檔案來在 Neo4J 中運行它以獲得默認的 GraphDatabase。

uj5u.com熱心網友回復：

您的查詢拋出一個，OutOfMemoryError因為您試圖一起匯入 3 個 csv，這樣總行數將是三個 CSV 的笛卡爾積。也就是說，如果您有 3 個包含 50 行的 csv，您將從前load csv50 個結果中收到，每個結果都有第二個load csv50 個結果，每個結果有第三個 50 個結果。因此，您將獲得 50x50x50 的結果。嘗試一次匯入一個csv，USING PERIODIC COMMIT NNN以防萬一，即：

LOAD CSV WITH HEADERS FROM
'file:///C:/Users/Enes/CSV_import/ingredients.csv'
    AS a
CREATE (ing:ingredients{name:a.ingredientName,
    ingredientName:a.ingredientName})

LOAD CSV WITH HEADERS FROM 
'file:///C:/Users/Enes/CSV_import/users.csv'
    AS b FIELDTERMINATOR ';'
CREATE (use:users{
    name:b.userName,
    userName:b.userName,
    userEmail:b.userEmail,
    userPassword:b.userPassword,
    enabled:b.enabled})

LOAD CSV WITH HEADERS FROM 
'file:///C:/Users/Enes/CSV_import/recipes.csv'
    AS c FIELDTERMINATOR ';'
CREATE (rec:recipe{
    name:c.recipeName,
    recipeName:c.recipeName,
    prepTimeInMin: c.prepTimeInMin,
    restTimeInMinutes: c.restTimeInMinutes,
    prepText: c.prepText,
    people: c.people,
    viewCount: c.viewCount,
    difficultyName: c.difficultyName,
    mealTypeName: c.mealTimeName,
    createdByUser: c.createdByUser})

編輯：

:auto USING PERIODIC COMMIT 200
LOAD CSV WITH HEADERS FROM
'file:///ingredients.csv'
    AS a
CREATE (ing:ingredients{name:a.ingredientName,
    ingredientName:a.ingredientName})

with 1 as ignored limit 1

LOAD CSV WITH HEADERS FROM 
'file:///users.csv'
    AS b FIELDTERMINATOR ';'
CREATE (use:users{
    name:b.userName,
    userName:b.userName,
    userEmail:b.userEmail,
    userPassword:b.userPassword,
    enabled:b.enabled})

with 1 as ignored limit 1

LOAD CSV WITH HEADERS FROM 
'file:///recipes.csv'
    AS c FIELDTERMINATOR ';'

CREATE (rec:recipe{
    name:c.recipeName,
    recipeName:c.recipeName,
    prepTimeInMin: c.prepTimeInMin,
    restTimeInMinutes: c.restTimeInMinutes,
    prepText: c.prepText,
    people: c.people,
    viewCount: c.viewCount,
    difficultyName: c.difficultyName,
    mealTypeName: c.mealTimeName,
    createdByUser: c.createdByUser})

return 1 limit 1

標籤：mysql CSV 新4j 暗号

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