The results from database read and write must be processed properly before being used in your application.
Return a Response
Methods such as gql() and uql() return a Response object. To serve the application, you need to first extract the DataItem from the Response object, and then transform it into an appropriate driver data structure.
A Response object includes the following attributes:
Attribute |
Type |
Description |
|---|---|---|
aliases |
List[Alias] |
The list of result aliases; each Alias includes attributes alias (the alias name) and type (the result type). |
items |
Dict[str, DataIem] |
A dictionary where the key is the alias name, and the value is the data it represents. |
explainPlan |
List[ExplainPlan] |
A list of execution plans. |
status |
Status |
The status of the execution, inlcuding attributes code and message. |
statistics |
Statistics |
Statistics related to the insertion, including attributes nodeAffected, edgeAffected, totalCost, and engineCost. |
Extract DataItem
To extract DataItem from a Response object, use the get() or alias() method.
A DataItem object includes the following attributes:
Attribute |
Type |
Description |
|---|---|---|
alias |
str | The alias name. |
type |
str | The type of the results. |
entities |
list | The list of result entities. |
get()
Retrieves data by the alias index.
Parameters
int: Index of the alias.
Returns
DataItem: The returned data.
response = Conn.gql("MATCH (n)-[e]->() RETURN n, e LIMIT 3")
print(response.get(0).toJSON())
The GQL query returns two aliases (n, e), and the get() method gets the DataItem of the alias n at index 0.
{"alias": "n", "entities": [{"uuid": 72059793061183504, "id": "ULTIPA800000000000003B", "schema": "account", "values": {"gender": "female", "industry": "Publishing", "name": "Velox", "year": 1976}}, {"uuid": 648520545364606993, "id": "ULTIPA800000000000003E", "schema": "account", "values": {"gender": "female", "industry": "Food&Beverage", "name": "Claire", "year": 1989}}, {"uuid": 720578139402534937, "id": "ULTIPA8000000000000050", "schema": "account", "values": {"gender": "male", "industry": "Education", "name": "Holly", "year": 2000}}], "type": "NODE"}
alias()
Retrieves data by the alias name.
Parameters
str: Name of the alias.
Returns
DataItem: The returned data.
response = Conn.gql("MATCH (n)-[e]->() RETURN n, e LIMIT 3")
print(response.alias("e").toJSON())
The GQL query returns two aliases (n, e), and the alias() method gets DataItem of the alias e.
{"alias": "e", "entities": [{"schema": "agree", "uuid": 139, "fromId": "ULTIPA800000000000000E", "toId": "ULTIPA800000000000000D", "fromUuid": 6269012880322985990, "toUuid": 7998395137233256453, "values": {"targetPost": 905, "timestamp": 1572662452, "datetime": "2019-11-02 18:40:52"}}, {"schema": "agree", "uuid": 167, "fromId": "ULTIPA800000000000000E", "toId": "ULTIPA800000000000000F", "fromUuid": 6269012880322985990, "toUuid": 8214567919347040263, "values": {"targetPost": 1419, "timestamp": 1554431053, "datetime": "2019-04-05 18:24:13"}}, {"schema": "agree", "uuid": 15, "fromId": "ULTIPA8000000000000065", "toId": "ULTIPA8000000000000067", "fromUuid": 6629300850512625701, "toUuid": 5764609722057490465, "values": {"targetPost": 1374, "timestamp": 1552775174, "datetime": "2019-03-17 14:26:14"}}], "type": "EDGE"}
Transform DataItem
You should use a DataItem.as<DataStructure>() method to convert the DataItem into the corresponding driver data structure.
For example, the GQL query contained in the request below retrieves 3 nodes from the graph, the asNodes() method is used to convert the DataItem associated with the alias n into a list of Node objects:
response = Conn.gql("MATCH (n) RETURN n LIMIT 3")
nodeList = response.alias('n').asNodes()
for node in nodeList:
print(node.getID())
The following are all the transformation methods available on DataItem. Please note the applicable DataItem.type and DataItem.alias of each method.
Method |
DataItem.type |
DataItem.alias |
Returns |
Description |
|---|---|---|---|---|
asNodes() |
NODE | Any | List[Node] |
Converts to a list of Node objects. |
asFirstNode() |
NODE | Any | Node |
Converts the first returned entity to a Node object. |
asEdges() |
EDGE | Any | List[Edge] |
Converts to a list of Edge objects. |
asFirstEdge() |
EDGE | Any | Edge |
Converts the first returned entity to an Edge object. |
asGraph() |
GRAPH | Any | Graph |
Converts to a Graph object. |
asGraphSets() |
TABLE | _graph |
List[GraphSet] |
Converts to a list of GraphSet objects. |
asSchemas() |
TABLE | _nodeSchema, _edgeSchema |
List[Schema] |
Converts to a list of Schema objects. |
asProperties() |
TABLE | _nodeProperty, _edgeProperty |
List[Property] |
Converts to a list of Property objects. |
asAttr() |
ATTR | Any | Attr |
Converts to an Attr object. |
asTable() |
TABLE | Any | Table |
Converts to a Table object. |
asHDCGraphs() |
TABLE | _hdcGraphList |
List[HDCGraph] |
Converts to a list of HDCGraph objects. |
asAlgos() |
TABLE | _algoList |
List[Algo] |
Converts to a list of Algo objects. |
asProjections() |
TABLE | _projectionList |
List[Projection] |
Converts to a list of Projection objects. |
asIndexes() |
TABLE | _nodeIndex, _edgeIndex, _nodeFulltext, _edgeFulltext |
List[Index] |
Converts to a list of Index objects. |
asPrivilieges() |
TABLE | _privilege |
List[Priviliege] |
Converts to a list of Priviliege objects. |
asPolicies() |
TABLE | _policy |
List[Policy] |
Converts to a list of Policy objects. |
asUsers() |
TABLE | _user |
List[User] |
Converts to a list of User objects. |
asProcesses() |
TABLE | _top |
List[Process] |
Converts to a list of Process objects. |
asJobs() |
TABLE | _job |
List[Job] |
Converts to a list of Job objects. |
Return a ResponseWithExistCheck
Methods such as createGraphIfNotExist() return a ResponseWithExistCheck object.
A ResponseWithExistCheck object includes the following attributes:
Attribute |
Type |
Description |
|---|---|---|
exist |
bool | Whether the object to create already exist. |
response |
Response |
Main response of the method. |
Return an InsertResponse
Some data insertion methods such as insertNodesBatchBySchema() and insertNodesBatchAuto() return an InsertResponse object.
An InsertResponse object includes the following attributes:
Attribute |
Type |
Description |
|---|---|---|
ids |
List[str] | The list of _ids of the inserted nodes; note that the list is empty when InsertRequestConfig.silent is True. |
uuids |
List[int] | The list of _uuids of the inserted edges; note that the list is empty when InsertRequestConfig.silent is True. |
errorItems |
Dict[int,str] | A dictionary containing error details, where each key represents the index of a node or edge with an error, and the value is the error code and message. |
status |
Status |
The status of the insertion, inlcuding attributes code and message. |
statistics |
Statistics |
Statistics releated to the insertion, including attributes nodeAffected, edgeAffected, totalCost, and engineCost. |
Return a JobResponse
Methods such as createFulltext() return a JobResponse object.
A JobResponse object includes the following attributes:
Attribute |
Type |
Description |
|---|---|---|
jobId |
str | ID of the job of the execution. |
status |
Status |
The status of the insertion, inlcuding attributes code and message. |
statistics |
Statistics |
Statistics releated to the insertion, including attributes nodeAffected, edgeAffected, totalCost, and engineCost. |
Return a Driver Data Structure
Some methods return either a single instance or a list of driver data structures, which can be used directly. For example:
- The
getGraph()method returns a singleGraphSetobject. - The
showGraph()method returnsList[GraphSet].