As of January 1, 2020 this library no longer supports Python 2 on the latest released version. Library versions released prior to that date will continue to be available. For more information please visit Python 2 support on Google Cloud.

DB-API Reference

Google BigQuery implementation of the Database API Specification v2.0.

This module implements the Python Database API Specification v2.0 (DB-API) for Google BigQuery.

google.cloud.bigquery.dbapi.Binary(data)

Contruct a DB-API binary value.

Parameters

data (bytes-like) – An object containing binary data and that can be converted to bytes with the bytes builtin.

Returns

The binary data as a bytes object.

Return type

bytes

class google.cloud.bigquery.dbapi.Connection(client=None, bqstorage_client=None, prefer_bqstorage_client=True)

Bases: object

DB-API Connection to Google BigQuery.

Parameters

• client (Optional[google.cloud.bigquery.Client]) – A REST API client used to connect to BigQuery. If not passed, a client is created using default options inferred from the environment.

• bqstorage_client (Optional[google.cloud.bigquery_storage_v1.BigQueryReadClient]) – A client that uses the faster BigQuery Storage API to fetch rows from BigQuery. If not passed, it is created using the same credentials as client (provided that BigQuery Storage dependencies are installed).

• prefer_bqstorage_client (Optional[bool]) – Prefer the BigQuery Storage client over the REST client. If Storage client isn’t available, fall back to the REST client. Defaults to True.

close()

Close the connection and any cursors created from it.

Any BigQuery clients explicitly passed to the constructor are not closed, only those created by the connection instance itself.

commit()

No-op, but for consistency raise an error if connection is closed.

cursor()

Return a new cursor object.

Returns

A DB-API cursor that uses this connection.

Return type

google.cloud.bigquery.dbapi.Cursor

class google.cloud.bigquery.dbapi.Cursor(connection)

Bases: object

DB-API Cursor to Google BigQuery.

Parameters

connection (google.cloud.bigquery.dbapi.Connection) – A DB-API connection to Google BigQuery.

close()

Mark the cursor as closed, preventing its further use.

execute(operation, parameters=None, job_id=None, job_config=None)

Prepare and execute a database operation.

Note

When setting query parameters, values which are “text” (unicode in Python2, str in Python3) will use the ‘STRING’ BigQuery type. Values which are “bytes” (str in Python2, bytes in Python3), will use using the ‘BYTES’ type.

A ~datetime.datetime parameter without timezone information uses the ‘DATETIME’ BigQuery type (example: Global Pi Day Celebration March 14, 2017 at 1:59pm). A ~datetime.datetime parameter with timezone information uses the ‘TIMESTAMP’ BigQuery type (example: a wedding on April 29, 2011 at 11am, British Summer Time).

For more information about BigQuery data types, see: https://cloud.google.com/bigquery/docs/reference/standard-sql/data-types

STRUCT/RECORD and REPEATED query parameters are not yet supported. See: https://github.com/GoogleCloudPlatform/google-cloud-python/issues/3524

Parameters

• operation (str) – A Google BigQuery query string.

• parameters (Union[Mapping[str, Any], Sequence[Any]]) – (Optional) dictionary or sequence of parameter values.

• job_id (str | None) – (Optional and discouraged) The job ID to use when creating the query job. For best performance and reliability, manually setting a job ID is discouraged.

• job_config (google.cloud.bigquery.job.QueryJobConfig) – (Optional) Extra configuration options for the query job.

executemany(operation, seq_of_parameters)

Prepare and execute a database operation multiple times.

Parameters

• operation (str) – A Google BigQuery query string.

• seq_of_parameters (Union[Sequence[Mapping[str, Any], Sequence[Any]]]) – Sequence of many sets of parameter values.

fetchall()

Fetch all remaining results from the last execute*() call.

Note

If a dry run query was executed, no rows are returned.

Returns

A list of all the rows in the results.

Return type

List[Tuple]

Raises

google.cloud.bigquery.dbapi.InterfaceError – if called before execute().

fetchmany(size=None)

Fetch multiple results from the last execute*() call.

Note

If a dry run query was executed, no rows are returned.

Note

The size parameter is not used for the request/response size. Set the arraysize attribute before calling execute() to set the batch size.

Parameters

size (int) – (Optional) Maximum number of rows to return. Defaults to the arraysize property value. If arraysize is not set, it defaults to 1.

Returns

A list of rows.

Return type

List[Tuple]

Raises

google.cloud.bigquery.dbapi.InterfaceError – if called before execute().

fetchone()

Fetch a single row from the results of the last execute*() call.

Note

If a dry run query was executed, no rows are returned.

Returns

A tuple representing a row or None if no more data is available.

Return type

Tuple

Raises

google.cloud.bigquery.dbapi.InterfaceError – if called before execute().

property query_job: Optional[google.cloud.bigquery.job.query.QueryJob]

The query job created by the last execute*() call, if a query job was created.

Note

If the last execute*() call was executemany(), this is the last job created by executemany().

Type

google.cloud.bigquery.job.query.QueryJob | None

setinputsizes(sizes)

No-op, but for consistency raise an error if cursor is closed.

setoutputsize(size, column=None)

No-op, but for consistency raise an error if cursor is closed.

exception google.cloud.bigquery.dbapi.DataError

Bases: google.cloud.bigquery.dbapi.exceptions.DatabaseError

DB-API error due to problems with the processed data.

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception google.cloud.bigquery.dbapi.DatabaseError

Bases: google.cloud.bigquery.dbapi.exceptions.Error

DB-API error related to the database.

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

google.cloud.bigquery.dbapi.Date

alias of datetime.date

google.cloud.bigquery.dbapi.DateFromTicks(timestamp, /)

Create a date from a POSIX timestamp.

The timestamp is a number, e.g. created via time.time(), that is interpreted as local time.

exception google.cloud.bigquery.dbapi.Error

Bases: Exception

Exception representing all non-warning DB-API errors.

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception google.cloud.bigquery.dbapi.IntegrityError

Bases: google.cloud.bigquery.dbapi.exceptions.DatabaseError

DB-API error when integrity of the database is affected.

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception google.cloud.bigquery.dbapi.InterfaceError

Bases: google.cloud.bigquery.dbapi.exceptions.Error

DB-API error related to the database interface.

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception google.cloud.bigquery.dbapi.InternalError

Bases: google.cloud.bigquery.dbapi.exceptions.DatabaseError

DB-API error when the database encounters an internal error.

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception google.cloud.bigquery.dbapi.NotSupportedError

Bases: google.cloud.bigquery.dbapi.exceptions.DatabaseError

DB-API error for operations not supported by the database or API.

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception google.cloud.bigquery.dbapi.OperationalError

Bases: google.cloud.bigquery.dbapi.exceptions.DatabaseError

DB-API error related to the database operation.

These errors are not necessarily under the control of the programmer.

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

exception google.cloud.bigquery.dbapi.ProgrammingError

Bases: google.cloud.bigquery.dbapi.exceptions.DatabaseError

DB-API exception raised for programming errors.

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

google.cloud.bigquery.dbapi.Time

alias of datetime.time

google.cloud.bigquery.dbapi.TimeFromTicks(ticks, tz=None)

Construct a DB-API time value from the given ticks value.

Parameters

• ticks (float) – a number of seconds since the epoch; see the documentation of the standard Python time module for details.

• tz (datetime.tzinfo) – (Optional) time zone to use for conversion

Returns

time represented by ticks.

Return type

datetime.time

google.cloud.bigquery.dbapi.Timestamp

alias of datetime.datetime

google.cloud.bigquery.dbapi.TimestampFromTicks()

timestamp[, tz] -> tz’s local time from POSIX timestamp.

exception google.cloud.bigquery.dbapi.Warning

Bases: Exception

Exception raised for important DB-API warnings.

with_traceback()

Exception.with_traceback(tb) – set self.__traceback__ to tb and return self.

google.cloud.bigquery.dbapi.connect(client=None, bqstorage_client=None, prefer_bqstorage_client=True)

Construct a DB-API connection to Google BigQuery.

Parameters

• client (Optional[google.cloud.bigquery.Client]) – A REST API client used to connect to BigQuery. If not passed, a client is created using default options inferred from the environment.

• bqstorage_client (Optional[google.cloud.bigquery_storage_v1.BigQueryReadClient]) – A client that uses the faster BigQuery Storage API to fetch rows from BigQuery. If not passed, it is created using the same credentials as client (provided that BigQuery Storage dependencies are installed).

• prefer_bqstorage_client (Optional[bool]) – Prefer the BigQuery Storage client over the REST client. If Storage client isn’t available, fall back to the REST client. Defaults to True.

Returns

A new DB-API connection to BigQuery.

Return type

google.cloud.bigquery.dbapi.Connection

DB-API Query-Parameter Syntax

The BigQuery DB-API uses the qmark parameter style for unnamed/positional parameters and the pyformat parameter style for named parameters.

An example of a query using unnamed parameters:

insert into people (name, income) values (?, ?)

and using named parameters:

insert into people (name, income) values (%(name)s, %(income)s)

Providing explicit type information

BigQuery requires type information for parameters. The BigQuery DB-API can usually determine parameter types for parameters based on provided values. Sometimes, however, types can’t be determined (for example when None is passed) or are determined incorrectly (for example when passing a floating-point value to a numeric column).

The BigQuery DB-API provides an extended parameter syntax. For named parameters, a BigQuery type is provided after the name separated by a colon, as in:

insert into people (name, income) values (%(name:string)s, %(income:numeric)s)

For unnamed parameters, use the named syntax with a type, but no name, as in:

insert into people (name, income) values (%(:string)s, %(:numeric)s)

Providing type information is the only way to pass struct data:

cursor.execute(
  "insert into points (point) values (%(:struct<x float64, y float64>)s)",
  [{"x": 10, "y": 20}],
  )