以cypher / apoc格式执行多条件多查询

Question

我是neo4j cypher的新手，我试图构建一个多次使用apoc.do.when的图，但我遇到了一个问题，错误是：

Expected parameter(s): CT, vm_src, vm_dest, app_src, app_dest

我的Cypher查询是：

LOAD CSV WITH HEADERS FROM "file:///input.csv" AS CT

//Create vm
MERGE (vm_src:VM {name : CT.hostname_source})
MERGE (vm_dest:VM {name : CT.hostname_dest})

WITH vm_src, vm_dest

// create app with label Unknown_appli  
CALL apoc.do.when($CT.source_appli_name = "unknown_appli", 
'MERGE (app_src:App:Unknown_appli{name: "CT.hostname_source"}) RETURN app_src',
'MERGE (app_src:App{name:"CT.source_appli_name"}) RETURN app_src',
{CT:$CT}) YIELD value
WITH value.app_src as app_src

CALL apoc.do.when($CT.appli_name_dest = "unknown_appli" , 
'MERGE (app_dest:App:Unknown_appli{name: "CT.hostname_dest"}) RETURN app_dest',
'MERGE (app_dest:App{name: "CT.appli_name_dest"}) RETURN app_dest',
{CT:$CT}) YIELD value
WITH value.app_dest as app_dest


//create calls relations
CALL apoc.do.when($CT.direction = "IN" AND $vm_src.name <> $vm_dest.name , 
        'MERGE ($vm_dest)-[:CALLS]->($vm_src) RETURN $vm_dest', '',
        {CT:$CT,vm_src:$vm_src, vm_dest:$vm_dest}) YIELD value
WITH value as ignored

CALL apoc.do.when($CT.direction = "IN" AND $app_src.name <> $app_dest.name, 
        'MERGE (app_dest)-[:CALLS]->(app_src) RETURN app_dest', '', 
        {CT:$CT,app_src:$app_src, app_dest:$app_dest}) YIELD value
WITH value as ignored1


CALL apoc.do.when($CT.direction = "OUT" AND $vm_src.name <> $vm_dest.name, 
        'MERGE ($vm_src)-[:CALLS]->($vm_dest) RETURN $vm_src', '', 
        {CT:$CT,vm_src:$vm_src,vm_dest:$vm_dest}) YIELD value
WITH value as ignored2

CALL apoc.do.when($CT.direction = "OUT" AND $app_src.name <> $app_dest.name , 
        'MERGE (app_src)-[:CALLS]->(app_dest) RETURN app_src', '', 
        {CT:$CT,app_src:$app_src,app_dest:$app_dest}) YIELD value
WITH value as ignored3

//create child relations
MERGE (app_src)-[:CONTAINS]->(vm_src)
MERGE (app_dest)-[:CONTAINS]->(vm_dest)

有什么需要帮忙的吗？谢谢

Answer 1

以下是我在您的查询中发现的问题：

当参数不存在时，它有时会尝试使用它们(并且是unnecessary).

• It，有时不适当地用引号将参数括起来。)

1. It有时会尝试在参数不存在的时候使用它们。在这些情况下，它也不能在参数名之前使用"$“前缀。
2. 某些WITH子句不会传递后面的子句所需的所有变量。

这可能会更好地工作：

LOAD CSV WITH HEADERS FROM "file:///input.csv" AS CT

//Create vm
MERGE (vm_src:VM {name : CT.hostname_source})
MERGE (vm_dest:VM {name : CT.hostname_dest})

WITH CT, vm_src, vm_dest

// create app with label Unknown_appli  
CALL apoc.do.when(CT.source_appli_name = "unknown_appli", 
'MERGE (app_src:App:Unknown_appli{name: $CT.hostname_source}) RETURN app_src',
'MERGE (app_src:App{name: $CT.source_appli_name}) RETURN app_src',
{CT:CT}) YIELD value
WITH CT, vm_src, vm_dest, value.app_src as app_src

CALL apoc.do.when(CT.appli_name_dest = "unknown_appli", 
'MERGE (app_dest:App:Unknown_appli{name: $CT.hostname_dest}) RETURN app_dest',
'MERGE (app_dest:App{name: $CT.appli_name_dest}) RETURN app_dest',
{CT:CT}) YIELD value
WITH CT, vm_src, vm_dest, app_src, value.app_dest as app_dest

//create calls relations
CALL apoc.do.when(CT.direction = "IN" AND vm_src.name <> vm_dest.name, 
        'MERGE ($vm_dest)-[:CALLS]->($vm_src)', '',
        {CT:CT, vm_src:vm_src, vm_dest:vm_dest}) YIELD value
WITH CT, vm_src, vm_dest, app_src, value.app_dest as app_dest

CALL apoc.do.when(CT.direction = "IN" AND app_src.name <> app_dest.name, 
        'MERGE ($app_dest)-[:CALLS]->($app_src)', '', 
        {CT:CT,app_src:app_src, app_dest:app_dest}) YIELD value
WITH CT, vm_src, vm_dest, app_src, value.app_dest as app_dest

CALL apoc.do.when(CT.direction = "OUT" AND vm_src.name <> vm_dest.name, 
        'MERGE ($vm_src)-[:CALLS]->($vm_dest)', '', 
        {CT:CT,vm_src:vm_src,vm_dest:vm_dest}) YIELD value AS ignored1

CALL apoc.do.when(CT.direction = "OUT" AND app_src.name <> app_dest.name, 
        'MERGE ($app_src)-[:CALLS]->($app_dest) RETURN app_src', '', 
        {CT:CT,app_src:app_src,app_dest:app_dest}) YIELD value

//create child relations
MERGE (app_src)-[:CONTAINS]->(vm_src)
MERGE (app_dest)-[:CONTAINS]->(vm_dest)