Neo4j数据库更新命令在递归功能中不起作用（Neo4j中的AutoCommit）

Question

I am trying to update my neo4j Graph database with a query.

int recursiveFunction()
{
     try(Transaction tx1 = graphDb.beginTx();)
     {
     int val=recursiveFunction()
     if(val==0)
     {
                    try(Transaction tx1 = graphDb.beginTx();)
                    {
                        System.out.println("Competed node "+applicationName);
                        String updateQuery="    match(p:Problem) where p.value=\""+applicationName+"\"  set p.completed=1  return p";   
                        ExecutionResult updateExecResult = execEngine2.execute(updateQuery);
                        System.out.println("Updated complete flag for "+applicationName);
                        System.out.println("new value of updated is + "+updateExecResult.dumpToString());
                        tx1.success();
                        tx1.close();
                    }
                    catch(Exception e)
                    {
                        System.out.println("error in query");
                        e.printStackTrace();
                    }
    }
    catch(Exception e)
    {
     }
}

The value gets updated and it is been shown correctly when i do the results.dumpToString(). But when i continue again in the loop and come back again ,the value is not updated.Is it because i am doing the commit incorrectly.My issue is even if the value is getting updated inside the recursive function after that the changes are not getting reflected.Is there a way of AUTOCOMMIT in neo4j.

Answer 1

Your code will never even compile.

You should not name your transaction variables the same, the inner tx1 shadows the outer tx1

And the construct try () {} already does a close automatically, so you close your inner tx twice .

And your outer tx get's never committed, because you never call tx1.success() on it.

The inner transactions, don't actually commit, they are just placebo transactions, which make sure you can nest functions.

You function also never aborts, because you can it indefinitely.

int recursiveFunction() {
    try(Transaction tx1 = graphDb.beginTx()) {
       // todo abort-condition
       int val=recursiveFunction()
       if(val==0) {
          try(Transaction tx2 = graphDb.beginTx()) {
            String updateQuery="    match(p:Problem) where p.value=\""+applicationName+"\"  set p.completed=1  return p";   
            ExecutionResult updateExecResult = execEngine2.execute(updateQuery);
            tx2.success();
          } catch(Exception e2) {
            e2.printStackTrace();
          }
       }
       tx1.success();
    } catch(Exception e1) {
        e1.printStackTrace();
    }
}