Class Database (1.19.2)

Database(database_id, instance, ddl_statements=(), pool=None)

Representation of a Cloud Spanner Database.

We can use a Database to:

create the database
reload the database
update the database
drop the database

Parameters

Name	Description
database_id	`str` The ID of the database.
instance	`Instance` The instance that owns the database.
ddl_statements	`list of string` (Optional) DDL statements, excluding the CREATE DATABASE statement.
pool	`concrete subclass of AbstractSessionPool.` (Optional) session pool to be used by database. If not passed, the database will construct an instance of BurstyPool.

Inheritance

builtins.object > Database

Properties

create_time

Create time of this database.

Returns

Type	Description
`datetime.datetime`	a datetime object representing the create time of this database

ddl_statements

DDL Statements used to define database schema.

See cloud.google.com/spanner/docs/data-definition-language

Returns

Type	Description
sequence of string	the statements

name

Database name used in requests.

.. note::

This property will not change if database_id does not, but the return value is not cached.

The database name is of the form

``"projects/../instances/../databases/{database_id}"``

Returns

Type	Description
str	The database name.

restore_info

Restore info for this database.

Returns

Type	Description
RestoreInfo	an object representing the restore info for this database

spanner_api

Helper for session-related API calls.

state

State of this database.

Returns

Type	Description
State	an enum describing the state of the database

Methods

batch

batch()

Return an object which wraps a batch.

The wrapper must be used as a context manager, with the batch as the value returned by the wrapper.

Returns

Type	Description
BatchCheckout	new wrapper

batch_snapshot

batch_snapshot(read_timestamp=None, exact_staleness=None)

Return an object which wraps a batch read / query.

Parameters

Name	Description
read_timestamp	`datetime.datetime` Execute all reads at the given timestamp.
exact_staleness	`datetime.timedelta` Execute all reads at a timestamp that is `exact_staleness` old.

Returns

Type	Description
BatchSnapshot	new wrapper

create

create()

Create this database within its instance

Inclues any configured schema assigned to ddl_statements.

See https://cloud.google.com/spanner/reference/rpc/google.spanner.admin.database.v1#google.spanner.admin.database.v1.DatabaseAdmin.CreateDatabase

Exceptions

Type	Description
Conflict	if the database already exists
NotFound	if the instance owning the database does not exist

Returns

Type	Description
`google.api_core.operation.Operation`	a future used to poll the status of the create request

drop

drop()

Drop this database.

See https://cloud.google.com/spanner/reference/rpc/google.spanner.admin.database.v1#google.spanner.admin.database.v1.DatabaseAdmin.DropDatabase

execute_partitioned_dml

execute_partitioned_dml(dml, params=None, param_types=None, query_options=None)

Execute a partitionable DML statement.

Parameters

Name	Description
dml	`str` DML statement
params	`dict, {str -> column value}` values for parameter replacement. Keys must match the names used in `dml`.
param_types	`dict[str -> Union[dict, .types.Type]]` (Optional) maps explicit types for one or more param values; required if parameters are passed.
query_options	QueryOptions or `dict` (Optional) Query optimizer configuration to use for the given query. If a dict is provided, it must be of the same form as the protobuf message QueryOptions

Returns

Type	Description
int	Count of rows affected by the DML statement.

exists

exists()

Test whether this database exists.

See https://cloud.google.com/spanner/reference/rpc/google.spanner.admin.database.v1#google.spanner.admin.database.v1.DatabaseAdmin.GetDatabaseDDL

Returns

Type	Description
bool	True if the database exists, else false.

from_pb

from_pb(database_pb, instance, pool=None)

Creates an instance of this class from a protobuf.

Parameters

Name	Description
database_pb	`google.spanner.v2.spanner_instance_admin_pb2.Instance` A instance protobuf object.
instance	`Instance` The instance that owns the database.
pool	`concrete subclass of AbstractSessionPool.` (Optional) session pool to be used by database.

Exceptions

Type	Description
ValueError	if the instance name does not match the expected format or if the parsed project ID does not match the project ID on the instance's client, or if the parsed instance ID does not match the instance's ID.

Returns

Type	Description
`Database`	The database parsed from the protobuf response.

is_optimized

is_optimized()

Test whether this database has finished optimizing.

Returns

Type	Description
bool	True if the database state is READY, else False.

is_ready

is_ready()

Test whether this database is ready for use.

Returns

Type	Description
bool	True if the database state is READY_OPTIMIZING or READY, else False.

list_database_operations

list_database_operations(filter_="", page_size=None)

List database operations for the database.

Parameters

Name	Description
filter_	`str` Optional. A string specifying a filter for which database operations to list.
page_size	`int` Optional. The maximum number of operations in each page of results from this request. Non-positive values are ignored. Defaults to a sensible value set by the API. :type: `google.api_core.page_iterator.Iterator`

reload

reload()

Reload this database.

Refresh any configured schema into ddl_statements.

See https://cloud.google.com/spanner/reference/rpc/google.spanner.admin.database.v1#google.spanner.admin.database.v1.DatabaseAdmin.GetDatabaseDDL

Exceptions

Type	Description
NotFound	if the database does not exist

restore

restore(source)

Restore from a backup to this database.

Parameter

Name	Description
backup	`Backup` the path of the backup being restored from.

Exceptions

Type	Description
Conflict	if the database already exists
NotFound	if the instance owning the database does not exist, or if the backup being restored from does not exist
ValueError	if backup is not set

Returns

Type	Description
`google.api_core.operation.Operation`	a future used to poll the status of the create request

run_in_transaction

run_in_transaction(func, *args, **kw)

Perform a unit of work in a transaction, retrying on abort.

Parameters

Name	Description
args	`tuple` additional positional arguments to be passed to `func`.
kw	`dict` (Optional) keyword arguments to be passed to `func`. If passed, "timeout_secs" will be removed and used to override the default retry timeout which defines maximum timestamp to continue retrying the transaction.
func	`callable` takes a required positional argument, the transaction, and additional positional / keyword arguments as supplied by the caller.

Exceptions

Type	Description
Exception	reraises any non-ABORT execptions raised by ``func``.

Returns

Type	Description
Any	The return value of ``func``.

session

session(labels=None)

Factory to create a session for this database.

Parameter

Name	Description
labels	`dict (str -> str) or None` (Optional) user-assigned labels for the session.

Returns

Type	Description
Session	a session bound to this database.

snapshot

snapshot(**kw)

Return an object which wraps a snapshot.

The wrapper must be used as a context manager, with the snapshot as the value returned by the wrapper.

See https://cloud.google.com/spanner/reference/rpc/google.spanner.v1#google.spanner.v1.TransactionOptions.ReadOnly

Parameter

Name	Description
kw	`dict` Passed through to Snapshot constructor.

Returns

Type	Description
SnapshotCheckout	new wrapper

update_ddl

update_ddl(ddl_statements, operation_id="")

Update DDL for this database.

Apply any configured schema from ddl_statements.

See https://cloud.google.com/spanner/reference/rpc/google.spanner.admin.database.v1#google.spanner.admin.database.v1.DatabaseAdmin.UpdateDatabase

Parameters

Name	Description
ddl_statements	`Sequence[str]` a list of DDL statements to use on this database
operation_id	`str` (optional) a string ID for the long-running operation

Exceptions

Type	Description
NotFound	if the database does not exist

Returns

Type	Description
`google.api_core.operation.Operation`	an operation instance