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DB-API Reference

.. automodule:: google.cloud.bigquery.dbapi
  :members:
  :show-inheritance:

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}],
  )