Create Nested tree structure in neo4j - neo4j

Question

consider a situation . There is a company say A. So its a root node. Node is created (n: Comapny{id:'a',title:'A' parentId:''}) . A adds 2 depts say IT Team, the testing team. .So Node is created
({cl:ComapnyLeaf{id:'itTeam',title:'IT Team',parentId:'a'}); ({cl:ComapnyLeaf{id:'testingTeam',title:'TESTING Team',parentId:'a'}); Now it adds emapolyee
({cl:ComapnyLeaf{id:'emp1',title:'Emp 1',parentId:'itTeam'});
so while creating nodes relationship between them should be created my final out will look like
Company(A) < ---- child--- it Team <----child---emp1
< ---- child--- Testing Team

Answer 1

I think you need to recheck your query and your desired output, you have misspellings and bad syntax in there, and your output doesn't reflect your input. The testing team should end up being the child of :Company node a, not the Emp 1 :CompanyLeaf node.
Let's first create the nodes like this (you'll need to enable the multi-statement query editor in the Neo4j Browser preferences):
CREATE (n:Company:Node {id:'a', title:'A'});
CREATE (cl:CompanyLeaf:Node {id:'itTeam', title:'IT Team', parentId:'a'});
CREATE (cl:CompanyLeaf:Node {id:'testingTeam', title:'TESTING Team', parentId:'a'});
CREATE (cl:CompanyLeaf:Node {id:'emp1', title:'Emp 1', parentId:'itTeam'});
Then let's add an index on :Node(id) to support the fast lookups we'll need to create the relationships.
CREATE INDEX ON :Node(id)
Then for checking all :CompanyLeaf nodes in the graph and attaching them to a node with the given id as the parent, we can use this:
MATCH (c:CompanyLeaf)
WHERE NOT (c)-[:PARENT]->()
MATCH (parent:Node {id:c.parentId})
CREATE (c)-[:PARENT]->(parent)
The WHERE NOT clause here makes sure we don't create duplicate relationships in case we already ran the query, or in case we do several imports of nodes with relationship creation happening in between.
Also this is creating :PARENT relationships pointing the parent, since your example didn't make sense with :child relationships pointing to the parent.