This directory contains samples for Google Cloud Spanner. Google Cloud Spanner is a highly scalable, transactional, managed, NewSQL database service. Cloud Spanner solves the need for a horizontally-scaling database with consistent global transactions and SQL semantics.
Authentication is typically done through Application Default Credentials, which means you do not have to change the code to authenticate as long as your environment has credentials. You have a few options for setting up authentication:
When running locally, use the Google Cloud SDK
gcloud auth application-default login
When running on App Engine or Compute Engine, credentials are already set-up. However, you may need to configure your Compute Engine instance with additional scopes.
You can create a Service Account key file. This file can be used to authenticate to Google Cloud Platform services from any environment. To use the file, set the
GOOGLE_APPLICATION_CREDENTIALSenvironment variable to the path to the key file, for example:export GOOGLE_APPLICATION_CREDENTIALS=/path/to/service_account.json
Install pip and virtualenv if you do not already have them.
Create a virtualenv. Samples are compatible with Python 2.7 and 3.4+.
$ virtualenv env $ source env/bin/activateInstall the dependencies needed to run the samples.
$ pip install -r requirements.txt
To run this sample:
$ python snippets.py
usage: snippets.py [-h] [--database-id DATABASE_ID]
instance_id
{create_database,insert_data,query_data,read_data,add_column,update_data,query_data_with_new_column,read_write_transaction,read_only_transaction,add_index,query_data_with_index,read_data_with_index,add_storing_index,read_data_with_storing_index}
...
This application demonstrates how to do basic operations using Cloud
Spanner.
For more information, see the README.rst under /spanner.
positional arguments:
instance_id Your Cloud Spanner instance ID.
{create_database,insert_data,query_data,read_data,add_column,update_data,query_data_with_new_column,read_write_transaction,read_only_transaction,add_index,query_data_with_index,read_data_with_index,add_storing_index,read_data_with_storing_index}
create_database Creates a database and tables for sample data.
insert_data Inserts sample data into the given database. The
database and table must already exist and can be
created using `create_database`.
query_data Queries sample data from the database using SQL.
read_data Reads sample data from the database.
add_column Adds a new column to the Albums table in the example
database.
update_data 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
query_data_with_new_column
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
read_write_transaction
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.
read_only_transaction
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.
add_index Adds a simple index to the example database.
query_data_with_index
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
read_data_with_index
Inserts sample data into the given database. The
database and table must already exist and can be
created using `create_database`.
add_storing_index Adds an storing index to the example database.
read_data_with_storing_index
Inserts sample data into the given database. The
database and table must already exist and can be
created using `create_database`.
optional arguments:
-h, --help show this help message and exit
--database-id DATABASE_ID
Your Cloud Spanner database ID.This sample uses the Google Cloud Client Library for Python. You can read the documentation for more details on API usage and use GitHub to browse the source and report issues.