Class Database (3.2.0)

Database(database_id, instance, ddl_statements=(), pool=None, logger=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.
`logger`	`logging.Logger` (Optional) a custom logger that is used if `log_commit_stats` is `True` to log commit statistics. If not passed, a logger will be created when needed that will log the commit statistics to stdout.

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

earliest_version_time

The earliest time at which older versions of the data can be read.

Returns
Type	Description
`datetime.datetime`	a datetime object representing the earliest version time

logger

Logger used by the database.

The default logger will log commit stats at the log level INFO using sys.stderr.

Returns
Type	Description
`logging.Logger or None`	the logger

name

Database name used in requests.

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

"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

version_retention_period

The period in which Cloud Spanner retains all versions of data for the database.

Returns
Type	Description
`str`	a string representing the duration of the version retention period

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`	`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`

list_tables

list_tables()

List tables within the database.

:type: Iterable

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

table

table(table_id)

Factory to create a table object within this database.

Note: This method does not create a table in Cloud Spanner, but it can be used to check if a table exists.

my_table = database.table("my_table")
if my_table.exists():
    print("Table with ID 'my_table' exists.")
else:
    print("Table with ID 'my_table' does not exist.")

Parameter
Name	Description
`table_id`	`str` The ID of the table.

Returns
Type	Description
`Table`	a table owned by this database.

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

Class Database (3.2.0)

Parameters

Properties

create_time

ddl_statements

earliest_version_time

logger

name

restore_info

spanner_api

state

version_retention_period

Methods

batch

batch_snapshot

create

drop

execute_partitioned_dml

exists

from_pb

is_optimized

is_ready

list_database_operations

list_tables

reload

restore

run_in_transaction

session

snapshot

table

update_ddl