Version:

/query/graph

URL: http://GPUDB_IP_ADDRESS:GPUDB_PORT/query/graph

Employs a topological query on a network graph generated a-priori by /create/graph and returns a list of adjacent edge(s) or node(s), also known as an adjacency list, depending on what's been provided to the endpoint; providing edges will return nodes and providing nodes will return edges.

To determine the node(s) or edge(s) adjacent to a value from a given column, provide a list of values to input parameter queries. This field can be populated with column values from any table as long as the type is supported by the given identifier. See Query Identifiers for more information.

To return the adjacency list in the response, leave input parameter adjacency_table empty. To return the adjacency list in a table and not in the response, provide a value to input parameter adjacency_table and set export_query_results to false. To return the adjacency list both in a table and the response, provide a value to input parameter adjacency_table and set export_query_results to true.

See Network Graph Solver for more information.

Input Parameter Description

Name Type Description
graph_name string Name of the graph resource to query.
queries array of strings Nodes or edges to be queried specified using query identifiers. Identifiers can be used with existing column names, e.g., 'table.column AS QUERY_NODE_ID', raw values, e.g., '{0, 2} AS QUERY_NODE_ID', or expressions, e.g., 'ST_MAKEPOINT(table.x, table.y) AS QUERY_NODE_WKTPOINT'. Multiple values can be provided as long as the same identifier is used for all values. If using raw values in an identifier combination, the number of values specified must match across the combination.
restrictions array of strings Additional restrictions to apply to the nodes/edges of an existing graph. Restrictions must be specified using identifiers; identifiers are grouped as combinations. Identifiers can be used with existing column names, e.g., 'table.column AS RESTRICTIONS_EDGE_ID', expressions, e.g., 'column/2 AS RESTRICTIONS_VALUECOMPARED', or raw values, e.g., '{0, 0, 0, 1} AS RESTRICTIONS_ONOFFCOMPARED'. If using raw values in an identifier combination, the number of values specified must match across the combination. The default value is an empty array ( [] ).
adjacency_table string Name of the table to store the resulting adjacencies. If left blank, the query results are instead returned in the response even if export_query_results is set to false. If the 'QUERY_TARGET_NODE_LABEL' query identifier is used in input parameter queries, then two additional columns will be available: 'PATH_ID' and 'RING_ID'. See Using Labels for more information. The default value is ''.
rings int Only applicable when querying nodes. Sets the number of rings around the node to query for adjacency, with '1' being the edges directly attached to the queried node. Also known as number of hops. For example, if it is set to '2', the edge(s) directly attached to the queried node(s) will be returned; in addition, the edge(s) attached to the node(s) attached to the initial ring of edge(s) surrounding the queried node(s) will be returned. This setting can be '0' in which case if the node type id label, it'll then query for all that has the same property. The default value is 1.
options map of string to strings

Additional parameters. The default value is an empty map ( {} ).

Supported Parameters (keys) Parameter Description
force_undirected

This parameter is only applicable if the queried graph input parameter graph_name is directed and when querying nodes. If set to true, all inbound edges and outbound edges relative to the node will be returned. If set to false, only outbound edges relative to the node will be returned. The supported values are:

  • true
  • false
limit When specified, limits the number of query results. Note that if the target_nodes_table is provided, the size of the corresponding table will be limited by the limit value. The default value is an empty map ( {} ).
target_nodes_table Name of the table to store the list of the final nodes reached during the traversal. If this value is not given it'll default to adjacency_table+'_nodes'. The default value is ''.
restriction_threshold_value Value-based restriction comparison. Any node or edge with a RESTRICTIONS_VALUECOMPARED value greater than the restriction_threshold_value will not be included in the solution.
export_query_results

Returns query results in the response. If set to true, the output parameter adjacency_list_int_array (if the query was based on IDs), output parameter adjacency_list_string_array (if the query was based on names), or output parameter adjacency_list_wkt_array (if the query was based on WKTs) will be populated with the results. If set to false, none of the arrays will be populated. The supported values are:

  • true
  • false
enable_graph_draw

If set to true, adds a WKT-type column named 'QUERY_EDGE_WKTLINE' to the given input parameter adjacency_table and inputs WKT values from the source graph (if available) or auto-generated WKT values (if there are no WKT values in the source graph). A subsequent call to the /wms endpoint can then be made to display the query results on a map. The supported values are:

  • true
  • false
and_labels

If set to true, the result of the query has entities that satisfy all of the target labels, instead of any. The supported values are:

  • true
  • false

Output Parameter Description

The GPUdb server embeds the endpoint response inside a standard response structure which contains status information and the actual response to the query. Here is a description of the various fields of the wrapper:

Name Type Description
status String 'OK' or 'ERROR'
message String Empty if success or an error message
data_type String 'query_graph_request' or 'none' in case of an error
data String Empty string
data_str JSON or String

This embedded JSON represents the result of the /query/graph endpoint:

Name Type Description
result boolean Indicates a successful query.
adjacency_list_int_array array of longs The adjacency entity integer ID: either edge IDs per node requested (if using QUERY_EDGE_ID or QUERY_NODE1_ID and QUERY_NODE2_ID in the input) or two node IDs per edge requested (if using QUERY_NODE_ID in the input).
adjacency_list_string_array array of strings The adjacency entity string ID: either edge IDs per node requested (if using QUERY_EDGE_NAME or QUERY_NODE1_NAME and QUERY_NODE2_NAME in the input) or two node IDs per edge requested (if using QUERY_NODE_NAME in the input).
adjacency_list_wkt_array array of strings The adjacency entity WKTPOINT or WKTLINE ID: either edge IDs per node requested (if using QUERY_EDGE_WKTLINE or QUERY_NODE1_WKTPOINT and QUERY_NODE2_WKTPOINT in the input) or two node IDs per edge requested (if using QUERY_NODE_WKTPOINT in the input).
info map of string to strings Additional information.

Empty string in case of an error.