lucy-neo4j: add support for retrieving nodes based on relations holdi…

…ng data

dialects/neo4j.go

@@ -72,12 +72,12 @@ func (n *Neo4jRuntime) marshalToCypherBody(exp t.Exp) string {
 func (n *Neo4jRuntime) parseRelationToCypher(relName string, relType RelationType, data t.Exp) string {
  switch relType {
  case Neo4jUnidirectionalLeft:
- return fmt.Sprintf("CREATE (n)<-[:%s {%s}]-(m)", relName, n.marshalToCypherExp(data))
+ return fmt.Sprintf("(n)<-[:%s {%s}]-(m)", relName, n.marshalToCypherExp(data))
  case Neo4jUnidirectionalRight:
- return fmt.Sprintf("CREATE (n)-[:%s {%s}]->(m)", relName, n.marshalToCypherExp(data))
+ return fmt.Sprintf("(n)-[:%s {%s}]->(m)", relName, n.marshalToCypherExp(data))
  case Neo4jBidirectional:
  expStr := n.marshalToCypherExp(data)
- return fmt.Sprintf("CREATE (n)-[:%s {%s}]->(m), (n)<-[:%s {%s}]-(m)", relName, expStr, relName, expStr)
+ return fmt.Sprintf("(n)-[:%s {%s}]->(m), (n)<-[:%s {%s}]-(m)", relName, expStr, relName, expStr)
  default:
  return ""
  }
@@ -137,8 +137,8 @@ func (n *Neo4jRuntime) Compile(cradle *e.QueryCradle) (string, error) {
  genQuery = n.prefixNodeName(genQuery, kvp["nodeName"])
  return genQuery, nil
  } else if kvp["Context.Find"] == "Relation" {
- genQuery := fmt.Sprintf("MATCH (n: %s {%s})-[:%s]->(m: %s) RETURN {result: m}", kvp["classNameX"],
- kvp["cypherA"], kvp["relName"], kvp["className"])
+ genQuery := fmt.Sprintf("MATCH (n: %s {%s}), %s, (m: %s) RETURN {result: m}", kvp["classNameX"],
+ kvp["cypherA"], kvp["relExp"], kvp["className"])
  return genQuery, nil
  }
 
@@ -361,7 +361,7 @@ func (n *Neo4jRuntime) Compile(cradle *e.QueryCradle) (string, error) {
  if !ok {
  return "", e.Error(e.UnrecognizedExpression)
  }
- genQuery = fmt.Sprintf("MATCH (n: %s {%s}), (m: %s {%s}) %s", kvp["classNameX"],
+ genQuery = fmt.Sprintf("MATCH (n: %s {%s}), (m: %s {%s}) CREATE %s", kvp["classNameX"],
  kvp["matchExpX"], kvp["classNameY"], kvp["matchExpY"], n.parseRelationToCypher(relName, relType, t.Exp{}))
  } else if len(I) == 2 {
  // RelationType and Data passed in parameters.
@@ -371,12 +371,14 @@ func (n *Neo4jRuntime) Compile(cradle *e.QueryCradle) (string, error) {
  }
 
  exp, ok := I[1].(t.Exp)
+
+
  if !ok {
  return "", e.Error(e.UnrecognizedExpression)
  }
  e.SanitizeExp(exp)
 
- genQuery = fmt.Sprintf("MATCH (n: %s {%s}), (m: %s {%s}) %s", kvp["classNameX"],
+ genQuery = fmt.Sprintf("MATCH (n: %s {%s}), (m: %s {%s}) CREATE %s", kvp["classNameX"],
  kvp["matchExpX"], kvp["classNameY"], kvp["matchExpY"], n.parseRelationToCypher(relName, relType, exp))
  }
 
@@ -397,6 +399,29 @@ func (n *Neo4jRuntime) Compile(cradle *e.QueryCradle) (string, error) {
  e.SanitizeExp(outExp)
  kvp["cypherA"] = n.marshalToCypherExp(outExp)
  kvp["relName"] = pExp["relation"].(string)
+ I := pExp["params"].([]interface{})
+ if len(I) == 0 {
+ kvp["relExp"] = n.parseRelationToCypher(kvp["relName"], Neo4jUnidirectionalRight, t.Exp{})
+ } else if len(I) == 1 {
+ relType, ok := I[0].(RelationType)
+ if !ok {
+ return "", e.Error(e.UnrecognizedExpression)
+ }
+ kvp["relExp"] = n.parseRelationToCypher(kvp["relName"], relType, t.Exp{})
+ } else if len(I) == 2 {
+ relType, ok := I[0].(RelationType)
+ if !ok {
+ return "", e.Error(e.UnrecognizedExpression)
+ }
+
+ expr, ok := I[1].(t.Exp)
+ if !ok {
+ return "", e.Error(e.UnrecognizedExpression)
+ }
+ e.SanitizeExp(expr)
+
+ kvp["relExp"] = n.parseRelationToCypher(kvp["relName"], relType, expr)
+ }
  break
  }
  }