我有一个cypher来读取json文件，并做一些处理来创建/合并节点和关系，
// Read the json file
CALL apoc.load.json('file:///test/test.json') YIELD value
// Read the json fields as variables
with value.globalcustid as v_globalcustid, value.member_node_properties as member_node_properties, value.relationships as relationships
// Update the member node demographic properties, if the member node does not exist, create it
MERGE (m:Member {globalcustid: v_globalcustid})
ON CREATE SET m.age_group=member_node_properties.age_group, m.gender=member_node_properties.gender, m.education=member_node_properties.education
ON MATCH SET m.age_group=member_node_properties.age_group, m.gender=member_node_properties.gender, m.education=member_node_properties.education
// Unwind the relationships array into multiple rows of relationship
with v_globalcustid, m, member_node_properties, relationships
UNWIND relationships as r
// Get the tag node and skip the null tag
with m, v_globalcustid, r, r.node.label as node_label, r.node.tag_id as tag_id
where tag_id is not null
CALL apoc.cypher.run(
"MATCH (t:" + node_label + " {tag_id: '" + tag_id +"'}) RETURN t limit 1",
{}
) yield value as tag_node
// Merge the relationship of member node and tag node
with m, v_globalcustid, r, tag_node.t as tag_node
CALL apoc.merge.relationship(
m,
r.relationship.label,
{createdate: r.relationship.createdate, enddate: r.relationship.enddate, value: r.relationship.value},
{},
tag_node,
{}
) YIELD rel
return *字符串
cypher在一个小的json文件下工作得很好，然后我发现当json文件太大时，它会出现内存不足的错误，所以我决定把它放在批处理中。
:auto
// Read the json file
CALL apoc.load.json('file:///test/test.json') YIELD value
// Read the json fields as variables
with value.globalcustid as v_globalcustid, value.member_node_properties as member_node_properties, value.relationships as relationships
call {
with v_globalcustid, member_node_properties, relationships
// Update the member node demographic properties, if the member node does not exist, create it
MERGE (m:Member {globalcustid: v_globalcustid})
ON CREATE SET m.age_group=member_node_properties.age_group, m.gender=member_node_properties.gender, m.education=member_node_properties.education
ON MATCH SET m.age_group=member_node_properties.age_group, m.gender=member_node_properties.gender, m.education=member_node_properties.education
// Unwind the relationships array into multiple rows of relationship
with v_globalcustid, m, member_node_properties, relationships
UNWIND relationships as r
// Get the tag node and skip the null tag
with m, v_globalcustid, r, r.node.label as node_label, r.node.tag_id as tag_id
where tag_id is not null
CALL apoc.cypher.run(
"MATCH (t:" + node_label + " {tag_id: '" + tag_id +"'}) RETURN t limit 1",
{}
) yield value as tag_node
// Merge the relationship of member node and tag node
with m, v_globalcustid, r, tag_node.t as tag_node
CALL apoc.merge.relationship(
m,
r.relationship.label,
{createdate: r.relationship.createdate, enddate: r.relationship.enddate, value: r.relationship.value},
{},
tag_node,
{}
) YIELD rel
return *
} in transactions of 10000 rows型
但是看起来在call {}块中调用另一个过程是不起作用的。
Query cannot conclude with CALL together with YIELD (line 31, column 1 (offset: 1319))
"CALL apoc.merge.relationship("
^型
1条答案
按热度按时间uklbhaso1#
你的第二个查询应该失败，因为
RETURN *正在投射已经在外部作用域中声明的变量，例如v_globalcustid。要解决你原来的问题，只需返回
null：字符串
这是必要的，因为
CALL子查询必须以RETURN或写操作（如CREATE）结束。尽管apoc.merge.relationship确实执行写操作，但Cypher将其视为必须返回值的读操作。