@@ -94,11 +94,12 @@ def query_data(instance_id, database_id):
9494 instance = spanner_client .instance (instance_id )
9595 database = instance .database (database_id )
9696
97- results = database .execute_sql (
98- 'SELECT SingerId, AlbumId, AlbumTitle FROM Albums' )
97+ with database .snapshot () as snapshot :
98+ results = snapshot .execute_sql (
99+ 'SELECT SingerId, AlbumId, AlbumTitle FROM Albums' )
99100
100- for row in results :
101- print (u'SingerId: {}, AlbumId: {}, AlbumTitle: {}' .format (* row ))
101+ for row in results :
102+ print (u'SingerId: {}, AlbumId: {}, AlbumTitle: {}' .format (* row ))
102103
103104
104105def read_data (instance_id , database_id ):
@@ -107,14 +108,15 @@ def read_data(instance_id, database_id):
107108 instance = spanner_client .instance (instance_id )
108109 database = instance .database (database_id )
109110
110- keyset = spanner .KeySet (all_ = True )
111- results = database .read (
112- table = 'Albums' ,
113- columns = ('SingerId' , 'AlbumId' , 'AlbumTitle' ,),
114- keyset = keyset ,)
111+ with database .snapshot () as snapshot :
112+ keyset = spanner .KeySet (all_ = True )
113+ results = snapshot .read (
114+ table = 'Albums' ,
115+ columns = ('SingerId' , 'AlbumId' , 'AlbumTitle' ,),
116+ keyset = keyset ,)
115117
116- for row in results :
117- print (u'SingerId: {}, AlbumId: {}, AlbumTitle: {}' .format (* row ))
118+ for row in results :
119+ print (u'SingerId: {}, AlbumId: {}, AlbumTitle: {}' .format (* row ))
118120
119121
120122def query_data_with_new_column (instance_id , database_id ):
@@ -130,11 +132,13 @@ def query_data_with_new_column(instance_id, database_id):
130132 instance = spanner_client .instance (instance_id )
131133 database = instance .database (database_id )
132134
133- results = database .execute_sql (
134- 'SELECT SingerId, AlbumId, MarketingBudget FROM Albums' )
135+ with database .snapshot () as snapshot :
136+ results = snapshot .execute_sql (
137+ 'SELECT SingerId, AlbumId, MarketingBudget FROM Albums' )
135138
136- for row in results :
137- print (u'SingerId: {}, AlbumId: {}, MarketingBudget: {}' .format (* row ))
139+ for row in results :
140+ print (
141+ u'SingerId: {}, AlbumId: {}, MarketingBudget: {}' .format (* row ))
138142
139143
140144def add_index (instance_id , database_id ):
@@ -183,16 +187,18 @@ def query_data_with_index(
183187 'start_title' : type_pb2 .Type (code = type_pb2 .STRING ),
184188 'end_title' : type_pb2 .Type (code = type_pb2 .STRING )
185189 }
186- results = database .execute_sql (
187- "SELECT AlbumId, AlbumTitle, MarketingBudget "
188- "FROM Albums@{FORCE_INDEX=AlbumsByAlbumTitle} "
189- "WHERE AlbumTitle >= @start_title AND AlbumTitle < @end_title" ,
190- params = params , param_types = param_types )
191190
192- for row in results :
193- print (
194- u'AlbumId: {}, AlbumTitle: {}, '
195- 'MarketingBudget: {}' .format (* row ))
191+ with database .snapshot () as snapshot :
192+ results = snapshot .execute_sql (
193+ "SELECT AlbumId, AlbumTitle, MarketingBudget "
194+ "FROM Albums@{FORCE_INDEX=AlbumsByAlbumTitle} "
195+ "WHERE AlbumTitle >= @start_title AND AlbumTitle < @end_title" ,
196+ params = params , param_types = param_types )
197+
198+ for row in results :
199+ print (
200+ u'AlbumId: {}, AlbumTitle: {}, '
201+ 'MarketingBudget: {}' .format (* row ))
196202
197203
198204def read_data_with_index (instance_id , database_id ):
@@ -209,15 +215,16 @@ def read_data_with_index(instance_id, database_id):
209215 instance = spanner_client .instance (instance_id )
210216 database = instance .database (database_id )
211217
212- keyset = spanner .KeySet (all_ = True )
213- results = database .read (
214- table = 'Albums' ,
215- columns = ('AlbumId' , 'AlbumTitle' ),
216- keyset = keyset ,
217- index = 'AlbumsByAlbumTitle' )
218+ with database .snapshot () as snapshot :
219+ keyset = spanner .KeySet (all_ = True )
220+ results = snapshot .read (
221+ table = 'Albums' ,
222+ columns = ('AlbumId' , 'AlbumTitle' ),
223+ keyset = keyset ,
224+ index = 'AlbumsByAlbumTitle' )
218225
219- for row in results :
220- print ('AlbumId: {}, AlbumTitle: {}' .format (* row ))
226+ for row in results :
227+ print ('AlbumId: {}, AlbumTitle: {}' .format (* row ))
221228
222229
223230def add_storing_index (instance_id , database_id ):
@@ -252,17 +259,18 @@ def read_data_with_storing_index(instance_id, database_id):
252259 instance = spanner_client .instance (instance_id )
253260 database = instance .database (database_id )
254261
255- keyset = spanner .KeySet (all_ = True )
256- results = database .read (
257- table = 'Albums' ,
258- columns = ('AlbumId' , 'AlbumTitle' , 'MarketingBudget' ),
259- keyset = keyset ,
260- index = 'AlbumsByAlbumTitle2' )
262+ with database .snapshot () as snapshot :
263+ keyset = spanner .KeySet (all_ = True )
264+ results = snapshot .read (
265+ table = 'Albums' ,
266+ columns = ('AlbumId' , 'AlbumTitle' , 'MarketingBudget' ),
267+ keyset = keyset ,
268+ index = 'AlbumsByAlbumTitle2' )
261269
262- for row in results :
263- print (
264- u'AlbumId: {}, AlbumTitle: {}, '
265- 'MarketingBudget: {}' .format (* row ))
270+ for row in results :
271+ print (
272+ u'AlbumId: {}, AlbumTitle: {}, '
273+ 'MarketingBudget: {}' .format (* row ))
266274
267275
268276def add_column (instance_id , database_id ):
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