QueryResult

When you issue a query to the database through the con->execute(query) API, you are expected to get a queryResult which contains all result tuples for the given query. We provide variety of APIs for user to fetch the queryResult as their desired format.

class QueryResult()

Available APIs:

• __init__
• check_for_query_result_close Check if the query result is closed and raise an exception if it is.
• has_next Check if there are more rows in the query result.
• get_next Get the next row in the query result.
• write_to_csv Write the query result to a CSV file.
• close Close the query result.
• get_as_df Get the query result as a Pandas DataFrame.
• get_as_arrow Get the query result as a PyArrow Table.
• get_column_data_types Get the data types of the columns in the query result.
• get_column_names Get the names of the columns in the query result.
• reset_iterator Reset the iterator of the query result.
• get_as_networkx Converts the nodes and rels in query result into a NetworkX graph representation.
• get_as_torch_geometric Converts the nodes and rels in query result into a PyTorch Geometric graph representation torch_geometric.data.Data or torch_geometric.data.HeteroData.

__init__

def __init__(connection, query_result)

Parameters

• connection : _kuzu.Connection Connection to the database.

• query_result : _kuzu.QueryResult Query result.

check_for_query_result_close

def check_for_query_result_close()

Check if the query result is closed and raise an exception if it is.

Raises

• Exception If the query result is closed.

has_next

def has_next()

Check if there are more rows in the query result.

Returns

• bool True if there are more rows in the query result, False otherwise.

get_next

def get_next()

Get the next row in the query result.

Returns

• list Next row in the query result.

write_to_csv

def write_to_csv(filename, delimiter=',', escape_character='"', newline='\n')

Write the query result to a CSV file.

Parameters

• filename : str Name of the CSV file to write to.

• delimiter : str Delimiter to use in the CSV file. Defaults to ‘,’.

• escape_character : str Escape character to use in the CSV file. Defaults to ‘”’.

• newline : str Newline character to use in the CSV file. Defaults to ‘\n’.

close

def close()

Close the query result.

get_as_df

def get_as_df()

Get the query result as a Pandas DataFrame.

Returns

• pandas.DataFrame Query result as a Pandas DataFrame.

get_as_arrow

def get_as_arrow(chunk_size)

Get the query result as a PyArrow Table.

Parameters

• chunk_size : int Number of rows to include in each chunk.

Returns

• pyarrow.Table Query result as a PyArrow Table.

get_column_data_types

def get_column_data_types()

Get the data types of the columns in the query result.

Returns

• list Data types of the columns in the query result.

get_column_names

def get_column_names()

Get the names of the columns in the query result.

Returns

• list Names of the columns in the query result.

reset_iterator

def reset_iterator()

Reset the iterator of the query result.

get_as_networkx

def get_as_networkx(directed=True)

Convert the nodes and rels in query result into a NetworkX directed or undirected graph with the following rules:

• Columns with data type other than node or rel will be ignored.
• Duplicated nodes and rels will be converted only once.

Parameters

• directed : bool Whether the graph should be directed. Defaults to True.

Returns

• networkx.DiGraph or networkx.Graph Query result as a NetworkX graph.

get_as_torch_geometric

def get_as_torch_geometric()

Converts the nodes and rels in query result into a PyTorch Geometric graph representation torch_geometric.data.Data or torch_geometric.data.HeteroData.

For node conversion, numerical and boolean properties are directly converted into tensor and stored in Data/HeteroData. For properties cannot be converted into tensor automatically (please refer to the notes below for more detail), they are returned as unconverted_properties.

For rel conversion, rel is converted into edge_index tensor director. Rel properties are returned as edge_properties.

Node properties that cannot be converted into tensor automatically:

• If the type of a node property is not one of INT64, DOUBLE, or BOOL.
• If a node property contains a null value.
• If a node property contains a nested list of variable length (e.g. [[1,2],[3]]).
• If a node property is a list or nested list, but the shape is inconsistent (e.g. the list length is 6 for one node but 5 for another node).

Additional conversion rules:

• Columns with data type other than node or rel will be ignored.
• Duplicated nodes and rels will be converted only once.

Returns

• torch_geometric.data.Data or torch_geometric.data.HeteroData Query result as a PyTorch Geometric graph. Containing numeric or boolean node properties and edge_index tensor.
• dict A dictionary that maps the positional offset of each node in Data/HeteroData to its primary key in the database.
• dict A dictionary contains node properties that cannot be converted into tensor automatically. The order of values for each property is aligned with nodes in Data/HeteroData.
• dict A dictionary contains edge properties. The order of values for each property is aligned with edge_index in Data/HeteroData.