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#!/usr/bin/env python
# Copyright 2016 Google, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""This application demonstrates how to do basic operations using Cloud
Spanner.
For more information, see the README.rst under /spanner.
"""
import argparse
import base64
import datetime
from google.cloud import spanner
from google.cloud.spanner_v1 import param_types
# [START spanner_create_database]
def create_database(instance_id, database_id):
"""Creates a database and tables for sample data."""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id, ddl_statements=[
"""CREATE TABLE Singers (
SingerId INT64 NOT NULL,
FirstName STRING(1024),
LastName STRING(1024),
SingerInfo BYTES(MAX)
) PRIMARY KEY (SingerId)""",
"""CREATE TABLE Albums (
SingerId INT64 NOT NULL,
AlbumId INT64 NOT NULL,
AlbumTitle STRING(MAX)
) PRIMARY KEY (SingerId, AlbumId),
INTERLEAVE IN PARENT Singers ON DELETE CASCADE"""
])
operation = database.create()
print('Waiting for operation to complete...')
operation.result(120)
print('Created database {} on instance {}'.format(
database_id, instance_id))
# [END spanner_create_database]
# [START spanner_insert_data]
def insert_data(instance_id, database_id):
"""Inserts sample data into the given database.
The database and table must already exist and can be created using
`create_database`.
"""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
with database.batch() as batch:
batch.insert(
table='Singers',
columns=('SingerId', 'FirstName', 'LastName',),
values=[
(1, u'Marc', u'Richards'),
(2, u'Catalina', u'Smith'),
(3, u'Alice', u'Trentor'),
(4, u'Lea', u'Martin'),
(5, u'David', u'Lomond')])
batch.insert(
table='Albums',
columns=('SingerId', 'AlbumId', 'AlbumTitle',),
values=[
(1, 1, u'Total Junk'),
(1, 2, u'Go, Go, Go'),
(2, 1, u'Green'),
(2, 2, u'Forever Hold Your Peace'),
(2, 3, u'Terrified')])
print('Inserted data.')
# [END spanner_insert_data]
# [START spanner_delete_data]
def delete_data(instance_id, database_id):
"""Deletes sample data from the given database.
The database, table, and data must already exist and can be created using
`create_database` and `insert_data`.
"""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
# Delete individual rows
albums_to_delete = spanner.KeySet(
keys=[[2, 1], [2, 3]])
# Delete a range of rows where the column key is >=3 and <5
singers_range = spanner.KeyRange(start_closed=[3], end_open=[5])
singers_to_delete = spanner.KeySet(
ranges=[singers_range])
# Delete remaining Singers rows, which will also delete the remaining
# Albums rows because Albums was defined with ON DELETE CASCADE
remaining_singers = spanner.KeySet(all_=True)
with database.batch() as batch:
batch.delete('Albums', albums_to_delete)
batch.delete('Singers', singers_to_delete)
batch.delete('Singers', remaining_singers)
print('Deleted data.')
# [END spanner_delete_data]
# [START spanner_query_data]
def query_data(instance_id, database_id):
"""Queries sample data from the database using SQL."""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
with database.snapshot() as snapshot:
results = snapshot.execute_sql(
'SELECT SingerId, AlbumId, AlbumTitle FROM Albums')
for row in results:
print(u'SingerId: {}, AlbumId: {}, AlbumTitle: {}'.format(*row))
# [END spanner_query_data]
# [START spanner_read_data]
def read_data(instance_id, database_id):
"""Reads sample data from the database."""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
with database.snapshot() as snapshot:
keyset = spanner.KeySet(all_=True)
results = snapshot.read(
table='Albums',
columns=('SingerId', 'AlbumId', 'AlbumTitle',),
keyset=keyset,)
for row in results:
print(u'SingerId: {}, AlbumId: {}, AlbumTitle: {}'.format(*row))
# [END spanner_read_data]
# [START spanner_read_stale_data]
def read_stale_data(instance_id, database_id):
"""Reads sample data from the database. The data is exactly 15 seconds
stale."""
import datetime
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
staleness = datetime.timedelta(seconds=15)
with database.snapshot(exact_staleness=staleness) as snapshot:
keyset = spanner.KeySet(all_=True)
results = snapshot.read(
table='Albums',
columns=('SingerId', 'AlbumId', 'MarketingBudget',),
keyset=keyset)
for row in results:
print(u'SingerId: {}, AlbumId: {}, MarketingBudget: {}'.format(
*row))
# [END spanner_read_stale_data]
# [START spanner_query_data_with_new_column]
def query_data_with_new_column(instance_id, database_id):
"""Queries sample data from the database using SQL.
This sample uses the `MarketingBudget` column. You can add the column
by running the `add_column` sample or by running this DDL statement against
your database:
ALTER TABLE Albums ADD COLUMN MarketingBudget INT64
"""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
with database.snapshot() as snapshot:
results = snapshot.execute_sql(
'SELECT SingerId, AlbumId, MarketingBudget FROM Albums')
for row in results:
print(
u'SingerId: {}, AlbumId: {}, MarketingBudget: {}'.format(*row))
# [END spanner_query_data_with_new_column]
# [START spanner_create_index]
def add_index(instance_id, database_id):
"""Adds a simple index to the example database."""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
operation = database.update_ddl([
'CREATE INDEX AlbumsByAlbumTitle ON Albums(AlbumTitle)'])
print('Waiting for operation to complete...')
operation.result(120)
print('Added the AlbumsByAlbumTitle index.')
# [END spanner_create_index]
# [START spanner_query_data_with_index]
def query_data_with_index(
instance_id, database_id, start_title='Aardvark', end_title='Goo'):
"""Queries sample data from the database using SQL and an index.
The index must exist before running this sample. You can add the index
by running the `add_index` sample or by running this DDL statement against
your database:
CREATE INDEX AlbumsByAlbumTitle ON Albums(AlbumTitle)
This sample also uses the `MarketingBudget` column. You can add the column
by running the `add_column` sample or by running this DDL statement against
your database:
ALTER TABLE Albums ADD COLUMN MarketingBudget INT64
"""
from google.cloud.spanner_v1.proto import type_pb2
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
params = {
'start_title': start_title,
'end_title': end_title
}
param_types = {
'start_title': type_pb2.Type(code=type_pb2.STRING),
'end_title': type_pb2.Type(code=type_pb2.STRING)
}
with database.snapshot() as snapshot:
results = snapshot.execute_sql(
"SELECT AlbumId, AlbumTitle, MarketingBudget "
"FROM Albums@{FORCE_INDEX=AlbumsByAlbumTitle} "
"WHERE AlbumTitle >= @start_title AND AlbumTitle < @end_title",
params=params, param_types=param_types)
for row in results:
print(
u'AlbumId: {}, AlbumTitle: {}, '
'MarketingBudget: {}'.format(*row))
# [END spanner_query_data_with_index]
# [START spanner_read_data_with_index]
def read_data_with_index(instance_id, database_id):
"""Reads sample data from the database using an index.
The index must exist before running this sample. You can add the index
by running the `add_index` sample or by running this DDL statement against
your database:
CREATE INDEX AlbumsByAlbumTitle ON Albums(AlbumTitle)
"""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
with database.snapshot() as snapshot:
keyset = spanner.KeySet(all_=True)
results = snapshot.read(
table='Albums',
columns=('AlbumId', 'AlbumTitle'),
keyset=keyset,
index='AlbumsByAlbumTitle')
for row in results:
print('AlbumId: {}, AlbumTitle: {}'.format(*row))
# [END spanner_read_data_with_index]
# [START spanner_create_storing_index]
def add_storing_index(instance_id, database_id):
"""Adds an storing index to the example database."""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
operation = database.update_ddl([
'CREATE INDEX AlbumsByAlbumTitle2 ON Albums(AlbumTitle)'
'STORING (MarketingBudget)'])
print('Waiting for operation to complete...')
operation.result(120)
print('Added the AlbumsByAlbumTitle2 index.')
# [END spanner_create_storing_index]
# [START spanner_read_data_with_storing_index]
def read_data_with_storing_index(instance_id, database_id):
"""Reads sample data from the database using an index with a storing
clause.
The index must exist before running this sample. You can add the index
by running the `add_soring_index` sample or by running this DDL statement
against your database:
CREATE INDEX AlbumsByAlbumTitle2 ON Albums(AlbumTitle)
STORING (MarketingBudget)
"""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
with database.snapshot() as snapshot:
keyset = spanner.KeySet(all_=True)
results = snapshot.read(
table='Albums',
columns=('AlbumId', 'AlbumTitle', 'MarketingBudget'),
keyset=keyset,
index='AlbumsByAlbumTitle2')
for row in results:
print(
u'AlbumId: {}, AlbumTitle: {}, '
'MarketingBudget: {}'.format(*row))
# [END spanner_read_data_with_storing_index]
# [START spanner_add_column]
def add_column(instance_id, database_id):
"""Adds a new column to the Albums table in the example database."""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
operation = database.update_ddl([
'ALTER TABLE Albums ADD COLUMN MarketingBudget INT64'])
print('Waiting for operation to complete...')
operation.result(120)
print('Added the MarketingBudget column.')
# [END spanner_add_column]
# [START spanner_update_data]
def update_data(instance_id, database_id):
"""Updates sample data in the database.
This updates the `MarketingBudget` column which must be created before
running this sample. You can add the column by running the `add_column`
sample or by running this DDL statement against your database:
ALTER TABLE Albums ADD COLUMN MarketingBudget INT64
"""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
with database.batch() as batch:
batch.update(
table='Albums',
columns=(
'SingerId', 'AlbumId', 'MarketingBudget'),
values=[
(1, 1, 100000),
(2, 2, 500000)])
print('Updated data.')
# [END spanner_update_data]
# [START spanner_read_write_transaction]
def read_write_transaction(instance_id, database_id):
"""Performs a read-write transaction to update two sample records in the
database.
This will transfer 200,000 from the `MarketingBudget` field for the second
Album to the first Album. If the `MarketingBudget` is too low, it will
raise an exception.
Before running this sample, you will need to run the `update_data` sample
to populate the fields.
"""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
def update_albums(transaction):
# Read the second album budget.
second_album_keyset = spanner.KeySet(keys=[(2, 2)])
second_album_result = transaction.read(
table='Albums', columns=('MarketingBudget',),
keyset=second_album_keyset, limit=1)
second_album_row = list(second_album_result)[0]
second_album_budget = second_album_row[0]
transfer_amount = 200000
if second_album_budget < transfer_amount:
# Raising an exception will automatically roll back the
# transaction.
raise ValueError(
'The second album doesn\'t have enough funds to transfer')
# Read the first album's budget.
first_album_keyset = spanner.KeySet(keys=[(1, 1)])
first_album_result = transaction.read(
table='Albums', columns=('MarketingBudget',),
keyset=first_album_keyset, limit=1)
first_album_row = list(first_album_result)[0]
first_album_budget = first_album_row[0]
# Update the budgets.
second_album_budget -= transfer_amount
first_album_budget += transfer_amount
print(
'Setting first album\'s budget to {} and the second album\'s '
'budget to {}.'.format(
first_album_budget, second_album_budget))
# Update the rows.
transaction.update(
table='Albums',
columns=(
'SingerId', 'AlbumId', 'MarketingBudget'),
values=[
(1, 1, first_album_budget),
(2, 2, second_album_budget)])
database.run_in_transaction(update_albums)
print('Transaction complete.')
# [END spanner_read_write_transaction]
# [START spanner_read_only_transaction]
def read_only_transaction(instance_id, database_id):
"""Reads data inside of a read-only transaction.
Within the read-only transaction, or "snapshot", the application sees
consistent view of the database at a particular timestamp.
"""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
with database.snapshot(multi_use=True) as snapshot:
# Read using SQL.
results = snapshot.execute_sql(
'SELECT SingerId, AlbumId, AlbumTitle FROM Albums')
print('Results from first read:')
for row in results:
print(u'SingerId: {}, AlbumId: {}, AlbumTitle: {}'.format(*row))
# Perform another read using the `read` method. Even if the data
# is updated in-between the reads, the snapshot ensures that both
# return the same data.
keyset = spanner.KeySet(all_=True)
results = snapshot.read(
table='Albums',
columns=('SingerId', 'AlbumId', 'AlbumTitle',),
keyset=keyset,)
print('Results from second read:')
for row in results:
print(u'SingerId: {}, AlbumId: {}, AlbumTitle: {}'.format(*row))
# [END spanner_read_only_transaction]
# [START spanner_create_table_with_timestamp_column]
def create_table_with_timestamp(instance_id, database_id):
"""Creates a table with a COMMIT_TIMESTAMP column."""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
operation = database.update_ddl([
"""CREATE TABLE Performances (
SingerId INT64 NOT NULL,
VenueId INT64 NOT NULL,
EventDate Date,
Revenue INT64,
LastUpdateTime TIMESTAMP NOT NULL
OPTIONS(allow_commit_timestamp=true)
) PRIMARY KEY (SingerId, VenueId, EventDate),
INTERLEAVE IN PARENT Singers ON DELETE CASCADE"""
])
print('Waiting for operation to complete...')
operation.result(120)
print('Created Performances table on database {} on instance {}'.format(
database_id, instance_id))
# [END spanner_create_table_with_timestamp_column]
# [START spanner_insert_data_with_timestamp_column]
def insert_data_with_timestamp(instance_id, database_id):
"""Inserts data with a COMMIT_TIMESTAMP field into a table. """
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
with database.batch() as batch:
batch.insert(
table='Performances',
columns=(
'SingerId', 'VenueId', 'EventDate',
'Revenue', 'LastUpdateTime',),
values=[
(1, 4, "2017-10-05", 11000, spanner.COMMIT_TIMESTAMP),
(1, 19, "2017-11-02", 15000, spanner.COMMIT_TIMESTAMP),
(2, 42, "2017-12-23", 7000, spanner.COMMIT_TIMESTAMP)])
print('Inserted data.')
# [END spanner_insert_data_with_timestamp_column]
# [START spanner_add_timestamp_column]
def add_timestamp_column(instance_id, database_id):
""" Adds a new TIMESTAMP column to the Albums table in the example database.
"""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
operation = database.update_ddl([
'ALTER TABLE Albums ADD COLUMN LastUpdateTime TIMESTAMP '
'OPTIONS(allow_commit_timestamp=true)'])
print('Waiting for operation to complete...')
operation.result(120)
print('Altered table "Albums" on database {} on instance {}.'.format(
database_id, instance_id))
# [END spanner_add_timestamp_column]
# [START spanner_update_data_with_timestamp_column]
def update_data_with_timestamp(instance_id, database_id):
"""Updates Performances tables in the database with the COMMIT_TIMESTAMP
column.
This updates the `MarketingBudget` column which must be created before
running this sample. You can add the column by running the `add_column`
sample or by running this DDL statement against your database:
ALTER TABLE Albums ADD COLUMN MarketingBudget INT64
In addition this update expects the LastUpdateTime column added by
applying this DDL statement against your database:
ALTER TABLE Albums ADD COLUMN LastUpdateTime TIMESTAMP
OPTIONS(allow_commit_timestamp=true)
"""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
with database.batch() as batch:
batch.update(
table='Albums',
columns=(
'SingerId', 'AlbumId', 'MarketingBudget', 'LastUpdateTime'),
values=[
(1, 1, 1000000, spanner.COMMIT_TIMESTAMP),
(2, 2, 750000, spanner.COMMIT_TIMESTAMP)])
print('Updated data.')
# [END spanner_update_data_with_timestamp_column]
# [START spanner_query_data_with_timestamp_column]
def query_data_with_timestamp(instance_id, database_id):
"""Queries sample data from the database using SQL.
This updates the `LastUpdateTime` column which must be created before
running this sample. You can add the column by running the
`add_timestamp_column` sample or by running this DDL statement
against your database:
ALTER TABLE Performances ADD COLUMN LastUpdateTime TIMESTAMP
OPTIONS (allow_commit_timestamp=true)
"""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
with database.snapshot() as snapshot:
results = snapshot.execute_sql(
'SELECT SingerId, AlbumId, MarketingBudget FROM Albums '
'ORDER BY LastUpdateTime DESC')
for row in results:
print(u'SingerId: {}, AlbumId: {}, MarketingBudget: {}'.format(*row))
# [END spanner_query_data_with_timestamp_column]
# [START spanner_write_data_for_struct_queries]
def write_struct_data(instance_id, database_id):
"""Inserts sample data that can be used to test STRUCT parameters
in queries.
"""
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
with database.batch() as batch:
batch.insert(
table='Singers',
columns=('SingerId', 'FirstName', 'LastName',),
values=[
(6, u'Elena', u'Campbell'),
(7, u'Gabriel', u'Wright'),
(8, u'Benjamin', u'Martinez'),
(9, u'Hannah', u'Harris')])
print('Inserted sample data for STRUCT queries')
# [END spanner_write_data_for_struct_queries]
def query_with_struct(instance_id, database_id):
"""Query a table using STRUCT parameters. """
# [START spanner_create_struct_with_data]
record_type = param_types.Struct([
param_types.StructField('FirstName', param_types.STRING),
param_types.StructField('LastName', param_types.STRING)
])
record_value = ('Elena', 'Campbell')
# [END spanner_create_struct_with_data]
# [START spanner_query_data_with_struct]
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
with database.snapshot() as snapshot:
results = snapshot.execute_sql(
"SELECT SingerId FROM Singers WHERE "
"(FirstName, LastName) = @name",
params={'name': record_value},
param_types={'name': record_type})
for row in results:
print(u'SingerId: {}'.format(*row))
# [END spanner_query_data_with_struct]
def query_with_array_of_struct(instance_id, database_id):
"""Query a table using an array of STRUCT parameters. """
# [START spanner_create_user_defined_struct]
name_type = param_types.Struct([
param_types.StructField('FirstName', param_types.STRING),
param_types.StructField('LastName', param_types.STRING)])
# [END spanner_create_user_defined_struct]
# [START spanner_create_array_of_struct_with_data]
band_members = [("Elena", "Campbell"),
("Gabriel", "Wright"),
("Benjamin", "Martinez")]
# [END spanner_create_array_of_struct_with_data]
# [START spanner_query_data_with_array_of_struct]
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
with database.snapshot() as snapshot:
results = snapshot.execute_sql(
"SELECT SingerId FROM Singers WHERE "
"STRUCT<FirstName STRING, LastName STRING>"
"(FirstName, LastName) IN UNNEST(@names)",
params={'names': band_members},
param_types={'names': param_types.Array(name_type)})
for row in results:
print(u'SingerId: {}'.format(*row))
# [END spanner_query_data_with_array_of_struct]
# [START spanner_field_access_on_struct_parameters]
def query_struct_field(instance_id, database_id):
"""Query a table using field access on a STRUCT parameter. """
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
name_type = param_types.Struct([
param_types.StructField('FirstName', param_types.STRING),
param_types.StructField('LastName', param_types.STRING)
])
with database.snapshot() as snapshot:
results = snapshot.execute_sql(
"SELECT SingerId FROM Singers "
"WHERE FirstName = @name.FirstName",
params={'name': ("Elena", "Campbell")},
param_types={'name': name_type})
for row in results:
print(u'SingerId: {}'.format(*row))
# [START spanner_field_access_on_struct_parameters]
# [START spanner_field_access_on_nested_struct_parameters]
def query_nested_struct_field(instance_id, database_id):
"""Query a table using nested field access on a STRUCT parameter. """
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
song_info_type = param_types.Struct([
param_types.StructField('SongName', param_types.STRING),
param_types.StructField(
'ArtistNames', param_types.Array(
param_types.Struct([
param_types.StructField(
'FirstName', param_types.STRING),
param_types.StructField(
'LastName', param_types.STRING)
])
)
)
])
song_info = ('Imagination', [('Elena', 'Campbell'), ('Hannah', 'Harris')])
with database.snapshot() as snapshot:
results = snapshot.execute_sql(
"SELECT SingerId, @song_info.SongName "
"FROM Singers WHERE "
"STRUCT<FirstName STRING, LastName STRING>"
"(FirstName, LastName) "
"IN UNNEST(@song_info.ArtistNames)",
params={
'song_info': song_info
},
param_types={
'song_info': song_info_type
}
)
for row in results:
print(u'SingerId: {} SongName: {}'.format(*row))
# [END spanner_field_access_on_nested_struct_parameters]
def insert_data_with_dml(instance_id, database_id):
"""Inserts sample data into the given database using a DML statement. """
# [START spanner_dml_standard_insert]
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
def insert_singers(transaction):
row_ct = transaction.execute_update(
"INSERT Singers (SingerId, FirstName, LastName) "
" VALUES (10, 'Virginia', 'Watson')"
)
print("{} record(s) inserted.".format(row_ct))
database.run_in_transaction(insert_singers)
# [END spanner_dml_standard_insert]
def update_data_with_dml(instance_id, database_id):
"""Updates sample data from the database using a DML statement. """
# [START spanner_dml_standard_update]
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
def update_albums(transaction):
row_ct = transaction.execute_update(
"UPDATE Albums "
"SET MarketingBudget = MarketingBudget * 2 "
"WHERE SingerId = 1 and AlbumId = 1"
)
print("{} record(s) updated.".format(row_ct))
database.run_in_transaction(update_albums)
# [END spanner_dml_standard_update]
def delete_data_with_dml(instance_id, database_id):
"""Deletes sample data from the database using a DML statement. """
# [START spanner_dml_standard_delete]
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
def delete_singers(transaction):
row_ct = transaction.execute_update(
"DELETE FROM Singers WHERE FirstName = 'Alice'"
)
print("{} record(s) deleted.".format(row_ct))
database.run_in_transaction(delete_singers)
# [END spanner_dml_standard_delete]
def update_data_with_dml_timestamp(instance_id, database_id):
"""Updates data with Timestamp from the database using a DML statement. """
# [START spanner_dml_standard_update_with_timestamp]
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
def update_albums(transaction):
row_ct = transaction.execute_update(
"UPDATE Albums "
"SET LastUpdateTime = PENDING_COMMIT_TIMESTAMP() "
"WHERE SingerId = 1"
)
print("{} record(s) updated.".format(row_ct))
database.run_in_transaction(update_albums)
# [END spanner_dml_standard_update_with_timestamp]
def dml_write_read_transaction(instance_id, database_id):
"""First inserts data then reads it from within a transaction using DML."""
# [START spanner_dml_write_then_read]
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
def write_then_read(transaction):
# Insert record.
row_ct = transaction.execute_update(
"INSERT Singers (SingerId, FirstName, LastName) "
" VALUES (11, 'Timothy', 'Campbell')"
)
print("{} record(s) inserted.".format(row_ct))
# Read newly inserted record.
results = transaction.execute_sql(
"SELECT FirstName, LastName FROM Singers WHERE SingerId = 11"
)
for result in results:
print("FirstName: {}, LastName: {}".format(*result))
database.run_in_transaction(write_then_read)
# [END spanner_dml_write_then_read]
def update_data_with_dml_struct(instance_id, database_id):
"""Updates data with a DML statement and STRUCT parameters. """
# [START spanner_dml_structs]
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
record_type = param_types.Struct([
param_types.StructField('FirstName', param_types.STRING),
param_types.StructField('LastName', param_types.STRING)
])
record_value = ('Timothy', 'Campbell')
def write_with_struct(transaction):
row_ct = transaction.execute_update(
"UPDATE Singers SET LastName = 'Grant' "
"WHERE STRUCT<FirstName STRING, LastName STRING>"
"(FirstName, LastName) = @name",
params={'name': record_value},
param_types={'name': record_type}
)
print("{} record(s) updated.".format(row_ct))
database.run_in_transaction(write_with_struct)
# [END spanner_dml_structs]
def insert_with_dml(instance_id, database_id):
"""Inserts data with a DML statement into the database. """
# [START spanner_dml_getting_started_insert]
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
def insert_singers(transaction):
row_ct = transaction.execute_update(
"INSERT Singers (SingerId, FirstName, LastName) VALUES "
"(12, 'Melissa', 'Garcia'), "
"(13, 'Russell', 'Morales'), "
"(14, 'Jacqueline', 'Long'), "
"(15, 'Dylan', 'Shaw')"
)
print("{} record(s) inserted.".format(row_ct))
database.run_in_transaction(insert_singers)
# [END spanner_dml_getting_started_insert]
def query_data_with_parameter(instance_id, database_id):
"""Queries sample data from the database using SQL with a parameter."""
# [START spanner_query_with_parameter]
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
with database.snapshot() as snapshot:
results = snapshot.execute_sql(
"SELECT SingerId, FirstName, LastName FROM Singers "
"WHERE LastName = @lastName",
params={"lastName": "Garcia"},
param_types={"lastName": spanner.param_types.STRING})
for row in results:
print(u"SingerId: {}, FirstName: {}, LastName: {}".format(*row))
# [END spanner_query_with_parameter]
def write_with_dml_transaction(instance_id, database_id):
""" Transfers part of a marketing budget from one album to another. """
# [START spanner_dml_getting_started_update]
# instance_id = "your-spanner-instance"
# database_id = "your-spanner-db-id"
spanner_client = spanner.Client()
instance = spanner_client.instance(instance_id)
database = instance.database(database_id)
def transfer_budget(transaction):
# Transfer marketing budget from one album to another. Performed in a
# single transaction to ensure that the transfer is atomic.
second_album_result = transaction.execute_sql(
"SELECT MarketingBudget from Albums "
"WHERE SingerId = 2 and AlbumId = 2"
)
second_album_row = list(second_album_result)[0]
second_album_budget = second_album_row[0]
transfer_amount = 200000
# Transaction will only be committed if this condition still holds at