- 3.50.1 (latest)
- 3.50.0
- 3.46.0
- 3.45.0
- 3.44.0
- 3.43.0
- 3.42.0
- 3.41.0
- 3.40.1
- 3.39.0
- 3.38.0
- 3.37.0
- 3.36.0
- 3.35.1
- 3.34.0
- 3.33.0
- 3.32.0
- 3.31.0
- 3.30.0
- 3.29.0
- 3.28.0
- 3.27.1
- 3.26.0
- 3.25.0
- 3.24.0
- 3.23.0
- 3.22.2
- 3.21.0
- 3.20.0
- 3.19.0
- 3.18.0
- 3.17.0
- 3.16.0
- 3.15.1
- 3.14.1
- 3.13.0
- 3.12.1
- 3.11.1
- 3.10.0
- 3.9.0
- 3.8.0
- 3.7.0
- 3.6.0
- 3.5.0
- 3.4.0
- 3.3.0
- 3.2.0
- 3.1.0
- 3.0.0
- 2.1.1
- 2.0.0
- 1.19.3
- 1.18.0
- 1.17.1
- 1.16.0
- 1.15.1
- 1.14.0
- 1.13.0
- 1.12.0
- 1.11.0
- 1.10.0
Session(database, labels=None, database_role=None)
Representation of a Cloud Spanner Session.
We can use a Session
to:
create
the session- Use
exists
to check for the existence of the session drop
the session
Parameters |
|
---|---|
Name | Description |
database |
Database
The database to which the session is bound. |
labels |
dict (str -> str)
(Optional) User-assigned labels for the session. |
database_role |
str
(Optional) user-assigned database_role for the session. |
Properties
database_role
User-assigned database-role for the session.
Returns | |
---|---|
Type | Description |
str |
the database role str (None if no database role were assigned). |
labels
User-assigned labels for the session.
Returns | |
---|---|
Type | Description |
dict (str -> str) |
the labels dict (empty if no labels were assigned. |
name
Session name used in requests.
"projects/../instances/../databases/../sessions/{session_id}"
Exceptions | |
---|---|
Type | Description |
ValueError |
if session is not yet created |
Returns | |
---|---|
Type | Description |
str |
The session name. |
session_id
Read-only ID, set by the back-end during create
.
Methods
batch
batch()
Factory to create a batch for this session.
Exceptions | |
---|---|
Type | Description |
ValueError |
if the session has not yet been created. |
Returns | |
---|---|
Type | Description |
Batch |
a batch bound to this session |
create
create()
Create this session, bound to its database.
Exceptions | |
---|---|
Type | Description |
ValueError |
if session_id is already set. |
delete
delete()
Delete this session.
Exceptions | |
---|---|
Type | Description |
ValueError |
if session_id is not already set. |
NotFound |
if the session does not exist |
execute_sql
execute_sql(
sql,
params=None,
param_types=None,
query_mode=None,
query_options=None,
request_options=None,
retry=_MethodDefault._DEFAULT_VALUE,
timeout=_MethodDefault._DEFAULT_VALUE,
column_info=None,
)
Perform an ExecuteStreamingSql
API request.
Parameters | |
---|---|
Name | Description |
sql |
str
SQL query statement |
params |
dict, {str -> column value}
values for parameter replacement. Keys must match the names used in |
param_types |
dict, {str ->
(Optional) explicit types for one or more param values; overrides default type detection on the back-end. |
query_mode |
Mode governing return of results / query plan. See: |
query_options |
QueryOptions or
(Optional) Options that are provided for query plan stability. |
request_options |
RequestOptions
(Optional) Common options for this request. If a dict is provided, it must be of the same form as the protobuf message RequestOptions. |
retry |
(Optional) The retry settings for this request. |
timeout |
float
(Optional) The timeout for this request. |
column_info |
dict
(Optional) dict of mapping between column names and additional column information. An object where column names as keys and custom objects as corresponding values for deserialization. It's specifically useful for data types like protobuf where deserialization logic is on user-specific code. When provided, the custom object enables deserialization of backend-received column data. If not provided, data remains serialized as bytes for Proto Messages and integer for Proto Enums. |
Returns | |
---|---|
Type | Description |
StreamedResultSet |
a result set instance which can be used to consume rows. |
exists
exists()
Test for the existence of this session.
Returns | |
---|---|
Type | Description |
bool |
True if the session exists on the back-end, else False. |
ping
ping()
Ping the session to keep it alive by executing "SELECT 1".
Exceptions | |
---|---|
Type | Description |
ValueError |
if session_id is not already set. |
read
read(table, columns, keyset, index="", limit=0, column_info=None)
Perform a StreamingRead
API request for rows in a table.
Parameters | |
---|---|
Name | Description |
table |
str
name of the table from which to fetch data |
columns |
list of str
names of columns to be retrieved |
keyset |
KeySet
keys / ranges identifying rows to be retrieved |
index |
str
(Optional) name of index to use, rather than the table's primary key |
limit |
int
(Optional) maximum number of rows to return |
column_info |
dict
(Optional) dict of mapping between column names and additional column information. An object where column names as keys and custom objects as corresponding values for deserialization. It's specifically useful for data types like protobuf where deserialization logic is on user-specific code. When provided, the custom object enables deserialization of backend-received column data. If not provided, data remains serialized as bytes for Proto Messages and integer for Proto Enums. |
Returns | |
---|---|
Type | Description |
StreamedResultSet |
a result set instance which can be used to consume rows. |
run_in_transaction
run_in_transaction(func, *args, **kw)
Perform a unit of work in a transaction, retrying on abort.
Parameters | |
---|---|
Name | Description |
func |
callable
takes a required positional argument, the transaction, and additional positional / keyword arguments as supplied by the caller. |
args |
tuple
additional positional arguments to be passed to |
kw |
dict
(Optional) keyword arguments to be passed to |
Exceptions | |
---|---|
Type | Description |
Exception |
reraises any non-ABORT exceptions raised by func . |
Returns | |
---|---|
Type | Description |
Any |
The return value of func . |
snapshot
snapshot(**kw)
Create a snapshot to perform a set of reads with shared staleness.
Parameter | |
---|---|
Name | Description |
kw |
dict
Passed through to Snapshot ctor. |
Exceptions | |
---|---|
Type | Description |
ValueError |
if the session has not yet been created. |
Returns | |
---|---|
Type | Description |
Snapshot |
a snapshot bound to this session |
transaction
transaction()
Create a transaction to perform a set of reads with shared staleness.
Exceptions | |
---|---|
Type | Description |
ValueError |
if the session has not yet been created. |
Returns | |
---|---|
Type | Description |
Transaction |
a transaction bound to this session |