问题
I have a Question about the shortestPath() Function of OrientDB. If I Query select shortestPath('#9:1', '#15:1', 'BOTH') against a OrientDB I just get the Vertex of the Path. But I also want the Edges between them.
How can I SELECT both, the Vertex and the Edges?
回答1:
You can use a javascript function.
I used these records
I used this code
var g=orient.getGraph();
var b=g.command("sql","select expand(shortestPath(" + start + "," + end + ", 'BOTH'))");
var list=[];
for(i=0;i<b.length-1;i++){
var rid1=b[i].getId();
var rid2=b[i+1].getId();
var query="select from e where out = " + rid1 + " and in = " + rid2 + " limit 1";
var edge=g.command("sql",query);
list.push(b[i]);
list.push(edge[0]);
if(i==b.length-2){
list.push(b[i+1]);
}
}
return list;
Hope it helps.
回答2:
I tried this Java code with Alessandro's structure:
import java.util.ArrayList;
import java.util.List;
import com.orientechnologies.orient.client.remote.OServerAdmin;
import com.tinkerpop.blueprints.Direction;
import com.tinkerpop.blueprints.Edge;
import com.tinkerpop.blueprints.Vertex;
import com.tinkerpop.blueprints.impls.orient.OrientGraph;
public class myClass {
private boolean stop=false;
private List<Vertex> visitedNodesPreviousStep=new ArrayList<Vertex>();
private List<Vertex> visitedNodeCurrently=new ArrayList<Vertex>();
private List<List<Vertex>> path_vertex=new ArrayList<List<Vertex>>();
private List<List<Edge>> path_edges=new ArrayList<List<Edge>>();
private OrientGraph g;
int step=0;
public myClass(OrientGraph g) {
this.g=g;
}
protected List<Object> getDistance(String starting_rid, String ending_rid) {
Vertex starting_node=g.getVertex(starting_rid);
Vertex ending_node=g.getVertex(ending_rid);
visitedNodesPreviousStep.add(starting_node);
List<Vertex> p1=new ArrayList<Vertex>();
p1.add(starting_node);
path_vertex.add(p1);
step=1;
boolean found_node_to_be_added=false;
do{
stop=false;
found_node_to_be_added=false;
for(Vertex v: visitedNodesPreviousStep){
List<Edge> edges_to_be_added=new ArrayList<Edge>();
List<Vertex> nodes_to_be_added=new ArrayList<Vertex>();
Iterable<Edge> it_edge = (Iterable<Edge>) v.getEdges(Direction.OUT);
for(Edge e1:it_edge){
Vertex v1=e1.getVertex(Direction.IN);
edges_to_be_added.add(e1);
nodes_to_be_added.add(v1);
String rid=v1.getId().toString();
if(!rid.equals(ending_rid)){ // checking the current @rid isn't the ending
visitedNodeCurrently.add(v1);
}
else{ // ending node found
setPathFoundList(v,ending_node,step,e1);
stop=true;
}
}
if(nodes_to_be_added.size()!=0 && stop==false){
found_node_to_be_added=true;
setpath_vertex(v,nodes_to_be_added,edges_to_be_added);
}
}
if(found_node_to_be_added==false){
stop=true;
}
System.out.println("step = " + step + " " +path_vertex);
change();
step++;
}while(stop==false);
clean_vertex_path(ending_node);
return getShortestPathList();
}
public void change(){
visitedNodesPreviousStep.clear();
for(Vertex v:visitedNodeCurrently)
visitedNodesPreviousStep.add(v);
visitedNodeCurrently.clear();
}
private void setPathFoundList(Vertex node,Vertex ending_node,int step,Edge edge){
for(int i=0;i<path_vertex.size();i++){
List<Vertex> path=path_vertex.get(i);
Vertex last=path.get(path.size()-1);
if(last.getId().equals(node.getId()) && path.size()==step){
path.add(ending_node);
List<Edge> edgesPath=path_edges.get(i);
edgesPath.add(edge);
}
}
}
private void setpath_vertex(Vertex node,List<Vertex> nodes_to_be_added,List<Edge> edges_to_be_added) {
for(int i=0;i<path_vertex.size();i++){
List<Vertex> path=path_vertex.get(i);
Vertex last=path.get(path.size()-1);
if(last.getId().equals(node.getId())){
int j=0;
for(int h=0;h<nodes_to_be_added.size();h++){
boolean name_present=false;
for(Vertex p:path){
if(p.getId().equals(nodes_to_be_added.get(h).getId()))
name_present=true;
}
if(name_present==false){
List<Vertex> p2=new ArrayList<Vertex>();
for(Vertex p:path)
p2.add(p);
p2.add(nodes_to_be_added.get(h));
List<Edge> e2=new ArrayList<Edge>();
if(step==1){
e2.add(edges_to_be_added.get(h));
}
else{
List<Edge> edgesPath=path_edges.get(i);
for(Edge p1:edgesPath)
e2.add(p1);
e2.add(edges_to_be_added.get(h));
}
if(j==0){
path_vertex.set(i, p2);
if(step==1){
path_edges.add(i, e2);
}
else{
path_edges.set(i, e2);
}
j++;
}
else{
path_vertex.add(p2);
path_edges.add(e2);
}
}
}
}
}
}
public void clean_vertex_path(Vertex ending_node_name){
for(int i=0;i<path_vertex.size();i++){
List<Vertex> path=path_vertex.get(i);
if(!path.get(path.size()-1).getId().equals(ending_node_name.getId())){
path_vertex.remove(i);
path_edges.remove(i);
i--;
}
}
}
public List<Object> getShortestPathList(){
List<Object> result=new ArrayList<Object>();
if(path_vertex.size()==0)
return new ArrayList<Object>();
else{
List<Vertex> path=path_vertex.get(0);
int min_size= path.size();
for(int i=0;i<path_vertex.size();i++){
if(path_vertex.get(i).size()<=min_size){
List<Vertex> path2= path_vertex.get(i);
List<Edge> edges2= path_edges.get(i);
for(int k=0;k<path2.size();k++){
result.add(path2.get(k));
if(k!=path2.size()-1)
result.add(edges2.get(k));
}
}
}
}
return result;
}
public static void main(String[] args) {
String remote="remote:localhost/";
String DBname="Stack36794694";
String currentPath=remote+DBname;
OServerAdmin serverAdmin;
try {
serverAdmin = new OServerAdmin(currentPath).connect("root", "root");
if(serverAdmin.existsDatabase()){
OrientGraph g=new OrientGraph(currentPath);
myClass shortest2 = new myClass(g);
System.out.println("SHORTEST PATH " + shortest2.getDistance("#9:0","#9:5"));
}
}
catch(Exception e){
}
}
}
Hope it helps
来源：https://stackoverflow.com/questions/36794694/orientdb-get-edges-with-shortestpath