如何使用with子句正确地传递值

Question

我有一个很长的Cypher查询，在这个查询中，我从文件中加载记录，并尝试创建节点和关系。某些值可能不存在于文件中，因此节点和边缘的创建必须是有条件的。

我已经创建了查询的不同部分，并使用WITH语句，希望将对节点的引用传递给需要它们创建边的后续语句。

// Mandatory Nodes
MERGE (session:Session{sessionId:"_d6648bbf-f747-42e5-a9b0-adb2cb0aea66-F3AC584AA3E2969240F3E9B285F23C03"})
  ON CREATE SET session.ipAddress="207.54.58.254"
MERGE (user:User {UserId:"dfd75378-a6df-4101-aeb7-fc2f866a75cc"})
MERGE (environment:Environment{server:"qac-portal.qac.awsdev.acme.com", type:"MT"})
MERGE (browser:Browser{type:"Chrome"})
  ON CREATE SET browser.version="70"
MERGE (os:OS{name:"Win10"})
  ON CREATE SET os.version="Win10"
MERGE (device:Device{type:"10.0"})
MERGE (city:City{name:"Atlanta"})
MERGE (country:Country{name:"United States", code:"US"})
MERGE (geoLocation:GeoLocation{latitude:"33.8274", longitude:"-84.3244"})
MERGE (tenant:Tenant{TenantId:"TAMTA1AT2_AX1"})

// Edges between mandatory nodes. 
MERGE (session)-[:ASSIGNED_TO]->(user)
MERGE (session)-[:STARTED_AT]->(geoLocation)
MERGE (geoLocation)-[:COORDINATES_FOR]->(city)
MERGE (city)-[:LOCATED_IN]->(country)
MERGE (session)-[:CONNECTED_WITH]->(browser)
MERGE (browser)-[:RUNS_ON]->(device)
MERGE (browser)-[:SUPPORTS]->(os)
MERGE (os)-[:OPERATES]->(device)
MERGE (environment)-[:HOSTS]->(tenant)

WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant

// Optional nodes
CALL apoc.do.when(("TAMTA1AT2_AX1" <> ''),
"MERGE (company:Company{name:'TAMTA1AT2_AX1'})",
'', {})
YIELD value AS company

WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, company
CALL apoc.do.when(("" <> ''),
"MERGE (cloudSuite:CloudSuite{name:''})",
'', {})
YIELD value AS cloudSuite

WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, company, cloudSuite
CALL apoc.do.when(('sample-hr' <> ''),
"MERGE (application:Application{name:'sample-hr'})",
'', {})
YIELD value AS application

WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, company, cloudSuite, application
CALL apoc.do.when(('lid://acme.sample-hr.ng1' <> ''),
"MERGE (applicationInstance:ApplicationInstance{applicationId:'lid://acme.sample-hr.ng1'})",
'', {})
YIELD value AS applicationInstance

WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, company, cloudSuite, application, applicationInstance
CALL apoc.do.when(('sample-hr_form_Employee_LRCMyGoalsForm' <> ''),
"MERGE (screen:Screen{name:'sample-hr_form_Employee_LRCMyGoalsForm'})",
'', {})
YIELD value AS screen

WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, company, cloudSuite, application, applicationInstance, screen
CALL apoc.do.when(('sample-hr_form_Employee_LRCMyGoalsForm.ng1' <> '' ),
"MERGE (screenInstance:ScreenInstance{screenId:'sample-hr_form_Employee_LRCMyGoalsForm.ng1'})",
'', {})
YIELD value AS screenInstance

WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, company, cloudSuite, application, applicationInstance, screen, screenInstance
CALL apoc.do.when(((company IS NOT NULL) AND (tenant IS NOT NULL)),
'MERGE (company)-[r:OWNS]->(tenant)', '',{company:company, tenant:tenant}) YIELD value AS owns

// Edges between optional nodes
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant,
     company, cloudSuite, applicationInstance, application, screen, screenInstance
CALL apoc.do.when((("Accessed" = "Accessed") AND (screen IS NOT NULL) AND (screenInstance IS NOT NULL)),
'MERGE (screenInstance)-[r:INSTANCE_OF]->(screen)', '',{screen:screen, screenInstance:screenInstance}) YIELD value AS instanceOf

WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, company, cloudSuite, application, applicationInstance, screen, screenInstance
CALL apoc.do.when(((application IS NOT NULL) AND (applicationInstance IS NOT NULL)) AND ("Accessed" IN ["Accessed", "Launched", "Entered", "Exited"]),
'MERGE (application)-[r:DEPLOYS]->(applicationInstance)', '',{application:application, applicationInstance:applicationInstance}) YIELD value AS deploys

WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, company, cloudSuite, application, applicationInstance, screen, screenInstance
CALL apoc.do.when(((application IS NOT NULL) AND (cloudSuite IS NOT NULL)) AND ("Accessed" IN ["Accessed", "Launched", "Entered", "Exited"]),
'MERGE (application)-[r:BELONGS_TO]->(cloudSuite)' , '',{application:application, cloudSuite:cloudSuite}) YIELD value AS belongs_to

WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, company, cloudSuite, application, applicationInstance, screen, screenInstance
CALL apoc.do.when(((application IS NOT NULL) AND (browser IS NOT NULL)) AND ("Accessed" IN ["Accessed", "Launched", "Entered", "Exited"]),
'MERGE (application)-[r:COMPATIBLE_WITH]->(browser)', '',{application:application, browser:browser}) YIELD value AS compatible_with

WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, company, cloudSuite, application, applicationInstance, screen, screenInstance
CALL apoc.do.when((("Accessed" = "Accessed") AND (screenInstance IS NOT NULL) AND (applicationInstance IS NOT NULL)),
'MERGE (screenInstance)-[r:VIEWED_ON]->(applicationInstance)', '',{screenInstance:screenInstance, applicationInstance:applicationInstance}) YIELD value AS viewed_on

WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, company, cloudSuite, application, applicationInstance, screen, screenInstance
CALL apoc.do.when((("Accessed" = "Accessed") AND (application IS NOT NULL) AND (screen IS NOT NULL)),
'MERGE (application)-[:IMPLEMENTS]->(screen)', '',{application:application, screen:screen}) YIELD value AS implements

WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, company, cloudSuite, application, applicationInstance, screen, screenInstance
CALL apoc.do.when(((tenant IS NOT NULL) AND (application IS NOT NULL)),
'MERGE (tenant)-[r:PROVISIONED]->(application)', '',{tenant:tenant, application:application}) YIELD value AS provisioned

WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, company, cloudSuite, application, applicationInstance, screen, screenInstance
CALL apoc.do.case(
[ "Accessed" = "Logged In", "MERGE (session)-[:LOGGED_IN {start='2018-11-06 11:39:10'}]->(applicationInstance)",
  "Accessed" = "Logged Out", "MERGE (session)-[:LOGGED_OUT {end='2018-11-06 11:39:10'}]->(tenant)",
  "Accessed" = "Time Out", "MERGE (session)-[:TIMED_OUT {timeout='2018-11-06 11:39:10'}]->(tenant)",
  "Accessed" = "Accessed", 'MERGE (session)-[:ACCESSED]->(screenInstance)',
  "Accessed" = "Launched", 'MERGE (session)-[:LAUNCHED]->(applicationInstance)',
  "Accessed" = "Entered", 'MERGE (session)-[:ENTERED]->(applicationInstance)',
  "Accessed" = "Exited", 'MERGE (session)-[:EXITED]->(applicationInstance)' ],
'',
{applicationInstance:applicationInstance, screenInstance:screenInstance, session:session, tenant:tenant})
YIELD value AS action
RETURN *

当我在Neo4j浏览器上运行查询时，它执行并给出一个结果:添加10个标签，创建10个节点，设置16个属性，创建9个关系，在8ms之后完成。这意味着并不是所有的节点都是创建的。它实际上完成了前两个部分:强制节点和边缘，并在创建可选节点部分中的第一个节点："Company“之后立即停止。我不知道为什么会在那个时候停下来。我的猜测是，我在那里的with子句做错了什么，这就引出了我的下一个问题。我一定要用这几个吗？

提前感谢您的帮助。

编辑1

感谢解决了节点部分的问题：

CALL apoc.do.when(('xxxForm.ng1' <> '' ),
"MERGE (screenInstance:ScreenInstance{screenId:'ljhgjhn-gjhhkjhkhr_form_Employee_LRCMyGoalsForm.ng1'}) RETURN screenInstance",
'', {})
YIELD value
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, value.application as application, value.company as company, value.cloudSuite as cloudSuite, value.applicationInstance as applicationInstance, value.screen as screen, value.screenInstance as screenInstance

我假设使用值映射的相同方法会与边缘部分一起工作，但我在那里遇到了同样的问题。在这一点上，地图中的值是否仍然可用？

CALL apoc.do.when(((company IS NOT NULL) AND (tenant IS NOT NULL)),
'MERGE (company)-[r:OWNS]->(tenant) RETURN company, tenant', '',{company:company, tenant:tenant}) YIELD value
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, value.application as application, value.company as company, value.cloudSuite as cloudSuite, value.applicationInstance as applicationInstance, value.screen as screen, value.screenInstance as screenInstance

CALL apoc.do.when((("Accessed" = "Accessed") AND (screen IS NOT NULL) AND (screenInstance IS NOT NULL)),
'MERGE (screenInstance)-[r:INSTANCE_OF]->(screen) RETURN screenInstance, screen', '',{screen:screen, screenInstance:screenInstance}) YIELD value
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, value.application as application, value.company as company, value.cloudSuite as cloudSuite, value.applicationInstance as applicationInstance, value.screen as screen, value.screenInstance as screenInstance

编辑2

MERGE (session:Session{sessionId:"_d6648bbf-f747-42e5-a9b0-adb2cb0aea66-F3AC584AA3E2969240F3E9B285F23C03"})
  ON CREATE SET session.ipAddress="207.54.58.254"
WITH session

MERGE (user:User {UserId:"dfd75378-a6df-4101-aeb7-fc2f866a75cc"})
WITH session, user

MERGE (environment:Environment{server:"xxx.yyy.zzz.com", type:"MT"})
WITH session, user, environment

MERGE (browser:Browser{type:"Chrome"})
  ON CREATE SET browser.version="70"
WITH session, user, environment, browser

MERGE (os:OS{name:"Win10"})
  ON CREATE SET os.version="Win10"
WITH session, user, environment, browser, os

MERGE (device:Device{type:"10.0"})
WITH session, user, environment, browser, os, device

MERGE (city:City{name:"Atlanta"})
WITH session, user, environment, browser, os, device, city

MERGE (country:Country{name:"United States", code:"US"})
WITH session, user, environment, browser, os, device, city, country

MERGE (geoLocation:GeoLocation{latitude:"33.8274", longitude:"-84.3244"})
WITH session, user, environment, browser, os, device, city, country, geoLocation

MERGE (tenant:Tenant{TenantId:"TAMTA1AT2_AX1"})
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant

MERGE (session)-[:ASSIGNED_TO]->(user)
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant

MERGE (session)-[:STARTED_AT]->(geoLocation)
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant

MERGE (geoLocation)-[:COORDINATES_FOR]->(city)
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant

MERGE (city)-[:LOCATED_IN]->(country)
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant

MERGE (session)-[:CONNECTED_WITH]->(browser)
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant

MERGE (browser)-[:RUNS_ON]->(device)
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant

MERGE (browser)-[:SUPPORTS]->(os)
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant

MERGE (os)-[:OPERATES]->(device)
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant

MERGE (environment)-[:HOSTS]->(tenant)
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant

// Creating Optional nodes.
CALL apoc.do.when(('sfgsfgn-ghr' <> ''),
"MERGE (application:Application{name:'afasdfn-ghr'}) RETURN application",
'', {})
YIELD value AS mapApplication
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, mapApplication.application as application

CALL apoc.do.when(("TAMTA1AT2_AX1" <> ''),
"MERGE (company:Company{name:'TAMTA1AT2_AX1'}) RETURN company",
'', {})
YIELD value AS mapCompany
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, application, mapCompany.company as company

CALL apoc.do.when(("" <> ''),
"MERGE (cloudSuite:CloudSuite{name:''}) RETURN cloudSuite",
'', {})
YIELD value AS mapCloudSuite
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, application, company, mapCloudSuite.cloudSuite as cloudSuite

CALL apoc.do.when(('lid://afasfafdsghr.ng1' <> ''),
"MERGE (applicationInstance:ApplicationInstance{applicationId:'lid://gfsgsr.ng1'}) RETURN applicationInstance",
'', {})
YIELD value
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, application, company, cloudSuite, value.applicationInstance as applicationInstance

CALL apoc.do.when(('lawson-ghr_form_Employee_LRCMyGoalsForm' <> ''),
"MERGE (screen:Screen{name:'lafsafsdfn-ghr_form_Employee_LRCMyGoalsForm'}) RETURN screen",
'', {})
YIELD value
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, application, company, cloudSuite, applicationInstance, value.screen as screen

CALL apoc.do.when(('sfgfsg-ghr_form_Employee_LRCMyGoalsForm.ng1' <> '' ),
"MERGE (screenInstance:ScreenInstance{screenId:'sgfdn-ghr_form_Employee_LRCMyGoalsForm.ng1'}) RETURN screenInstance",
'', {})
YIELD value
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, application, company, cloudSuite, applicationInstance, screen, value.screenInstance as screenInstance

// Creating Edges for optional nodes
CALL apoc.do.when(((company IS NOT NULL) AND (tenant IS NOT NULL)),
'WITH company, tenant MERGE (company)-[r:OWNS]->(tenant)', '',{company:company, tenant:tenant}) YIELD value as owns
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, application, company, cloudSuite, applicationInstance, screen, screenInstance

CALL apoc.do.when((("Accessed" = "Accessed") AND (screen IS NOT NULL) AND (screenInstance IS NOT NULL)),
'WITH screen, screenInstance MERGE (screenInstance)-[i:INSTANCE_OF]->(screen)', '',{screenInstance:screenInstance, screen:screen}) YIELD value AS instance_of
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, application, company, cloudSuite, applicationInstance, screen, screenInstance

CALL apoc.do.when(((application IS NOT NULL) AND (applicationInstance IS NOT NULL)) AND ("Accessed" IN ["Accessed", "Launched", "Entered", "Exited"]),
'WITH application, applicationInstance MERGE (application)-[d:DEPLOYS]->(applicationInstance)', '',{application:application, applicationInstance:applicationInstance}) YIELD value AS deploys
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, application, company, cloudSuite, applicationInstance, screen, screenInstance

CALL apoc.do.when(((application IS NOT NULL) AND (cloudSuite IS NOT NULL)) AND ("Accessed" IN ["Accessed", "Launched", "Entered", "Exited"]),
'WITH application, cloudSuite MERGE (application)-[b:BELONGS_TO]->(cloudSuite)' , '',{application:application, cloudSuite:cloudSuite}) YIELD value AS belongs_to
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, application, company, cloudSuite, applicationInstance, screen, screenInstance

CALL apoc.do.when(((application IS NOT NULL) AND (browser IS NOT NULL)) AND ("Accessed" IN ["Accessed", "Launched", "Entered", "Exited"]),
"WITH application, browser MERGE (application)-[c:COMPATIBLE_WITH]->(browser)", '',{application:application, browser:browser}) YIELD value AS compatible_with
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, application, company, cloudSuite, applicationInstance, screen, screenInstance

CALL apoc.do.when((("Accessed" = "Accessed") AND (applicationInstance IS NOT NULL)),
"WITH screenInstance, applicationInstance MERGE (screenInstance)-[v:VIEWED_ON]->(applicationInstance)", '',{screenInstance:screenInstance, applicationInstance:applicationInstance}) YIELD value AS viewed_on
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, application, company, cloudSuite, applicationInstance, screen, screenInstance

CALL apoc.do.when((("Accessed" = "Accessed") AND (application IS NOT NULL) ),
"WITH application, screen MERGE (application)-[i:IMPLEMENTS]->(screen)", '',{application:application, screen:screen}) YIELD value AS implements
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, application, company, cloudSuite, applicationInstance, screen, screenInstance

CALL apoc.do.when(((tenant IS NOT NULL) AND (application IS NOT NULL)),
'WITH tenant, application MERGE (tenant)-[r:PROVISIONED]->(application)', '',{tenant:tenant, application:application}) YIELD value AS provisioned
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, application, company, cloudSuite, applicationInstance, screen, screenInstance

CALL apoc.do.case(
[ "Accessed" = "Logged In", "MERGE (session)-[:LOGGED_IN {start='2018-11-06 11:39:10'}]->(applicationInstance)",
  "Accessed" = "Logged Out", "MERGE (session)-[:LOGGED_OUT {end='2018-11-06 11:39:10'}]->(tenant)",
  "Accessed" = "Time Out", "MERGE (session)-[:TIMED_OUT {timeout='2018-11-06 11:39:10'}]->(tenant)",
  "Accessed" = "Accessed", 'MERGE (session)-[:ACCESSED]->(screenInstance)',
  "Accessed" = "Launched", 'MERGE (session)-[:LAUNCHED]->(applicationInstance)',
  "Accessed" = "Entered", 'MERGE (session)-[:ENTERED]->(applicationInstance)',
  "Accessed" = "Exited", 'MERGE (session)-[:EXITED]->(applicationInstance)' ],
'',
{applicationInstance:applicationInstance, session:session, tenant:tenant})
YIELD value
RETURN *

Answer 1

我认为这里最大的问题是在使用条件过程时犯了一个小错误。

如果要返回条件查询中的任何内容，则需要在查询中显式返回。

而且，返回的value是一个包含查询返回的值的映射，它不是值本身。看起来，您假设在对单个事物进行合并时，单个变量被隐式返回，并且可以通过value访问，但这是不正确的。正确的用法如下所示：

CALL apoc.do.when(("" <> ''),
"MERGE (cloudSuite:CloudSuite{name:''}) RETURN cloudSuite",
'', {})
YIELD value
WITH session, user, environment, browser, os, device, city, country, geoLocation, tenant, company, value.cloudSuite as cloudSuite, application

在值映射中派生的变量的混叠是在这种情况下(value.cloudSuite as cloudSuite)用于条件过程的所有用途的原因。

Answer 2

我解决了问题。我没有将变量作为参数传递，而是将结果从过程返回到主查询线程。