DML write then read

  void 
  
 DmlWriteThenRead 
 ( 
 google 
 :: 
 cloud 
 :: 
 spanner 
 :: 
 Client 
  
 client 
 ) 
  
 { 
  
 namespace 
  
 spanner 
  
 = 
  
 :: 
 google 
 :: 
 cloud 
 :: 
 spanner 
 ; 
  
 using 
  
 :: 
 google 
 :: 
 cloud 
 :: 
 StatusOr 
 ; 
  
 auto 
  
 commit_result 
  
 = 
  
 client 
 . 
 Commit 
 ( 
  
 [ 
& client 
 ]( 
 spanner 
 :: 
 Transaction 
  
 txn 
 ) 
  
 - 
>  
 StatusOr<spanner 
 :: 
 Mutations 
>  
 { 
  
 auto 
  
 insert 
  
 = 
  
 client 
 . 
 ExecuteDml 
 ( 
  
 txn 
 , 
  
 spanner 
 :: 
 SqlStatement 
 ( 
  
 "INSERT INTO Singers (SingerId, FirstName, LastName)" 
  
 "  VALUES (11, 'Timothy', 'Campbell')" 
 )); 
  
 if 
  
 ( 
 ! 
 insert 
 ) 
  
 return 
  
 std 
 :: 
 move 
 ( 
 insert 
 ). 
 status 
 (); 
  
 // Read newly inserted record. 
  
 spanner 
 :: 
 SqlStatement 
  
 select 
 ( 
  
 "SELECT FirstName, LastName FROM Singers where SingerId = 11" 
 ); 
  
 using 
  
 RowType 
  
 = 
  
 std 
 :: 
 tuple<std 
 :: 
 string 
 , 
  
 std 
 :: 
 string 
> ; 
  
 auto 
  
 rows 
  
 = 
  
 client 
 . 
 ExecuteQuery 
 ( 
 std 
 :: 
 move 
 ( 
 txn 
 ), 
  
 std 
 :: 
 move 
 ( 
 select 
 )); 
  
 // Note: This mutator might be re-run, or its effects discarded, so 
  
 // changing non-transactional state (e.g., by producing output) is, 
  
 // in general, not something to be imitated. 
  
 for 
  
 ( 
 auto 
  
 const 
&  
 row 
  
 : 
  
 spanner 
 :: 
 StreamOf<RowType> 
 ( 
 rows 
 )) 
  
 { 
  
 if 
  
 ( 
 ! 
 row 
 ) 
  
 return 
  
 std 
 :: 
 move 
 ( 
 row 
 ). 
 status 
 (); 
  
 std 
 :: 
 cout 
 << 
 "FirstName: " 
 << 
 std 
 :: 
 get<0> 
 ( 
 * 
 row 
 ) 
 << 
 " 
 \t 
 " 
 ; 
  
 std 
 :: 
 cout 
 << 
 "LastName: " 
 << 
 std 
 :: 
 get<1> 
 ( 
 * 
 row 
 ) 
 << 
 " 
 \n 
 " 
 ; 
  
 } 
  
 return 
  
 spanner 
 :: 
 Mutations 
 {}; 
  
 }); 
  
 if 
  
 ( 
 ! 
 commit_result 
 ) 
  
 throw 
  
 std 
 :: 
 move 
 ( 
 commit_result 
 ). 
 status 
 (); 
  
 std 
 :: 
 cout 
 << 
 "Write then read succeeded [spanner_dml_write_then_read] 
 \n 
 " 
 ; 
 } 
 

  using 
  
  Google.Cloud.Spanner.Data 
 
 ; 
 using 
  
 System 
 ; 
 using 
  
 System.Threading.Tasks 
 ; 
 public 
  
 class 
  
 WriteAndReadUsingDmlCoreAsyncSample 
 { 
  
 public 
  
 async 
  
 Task<int> 
  
 WriteAndReadUsingDmlCoreAsync 
 ( 
 string 
  
 projectId 
 , 
  
 string 
  
 instanceId 
 , 
  
 string 
  
 databaseId 
 ) 
  
 { 
  
 string 
  
 connectionString 
  
 = 
  
 $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}" 
 ; 
  
 using 
  
 var 
  
 connection 
  
 = 
  
 new 
  
  SpannerConnection 
 
 ( 
 connectionString 
 ); 
  
 await 
  
 connection 
 . 
  OpenAsync 
 
 (); 
  
 using 
  
 var 
  
 createDmlCmd 
  
 = 
  
 connection 
 . 
  CreateDmlCommand 
 
 ( 
 @"INSERT Singers (SingerId, FirstName, LastName) VALUES (11, 'Timothy', 'Campbell')" 
 ); 
  
 int 
  
 rowCount 
  
 = 
  
 await 
  
 createDmlCmd 
 . 
 ExecuteNonQueryAsync 
 (); 
  
 Console 
 . 
 WriteLine 
 ( 
 $"{rowCount} row(s) inserted..." 
 ); 
  
 // Read newly inserted record. 
  
 using 
  
 var 
  
 createSelectCmd 
  
 = 
  
 connection 
 . 
  CreateSelectCommand 
 
 ( 
 @"SELECT FirstName, LastName FROM Singers WHERE SingerId = 11" 
 ); 
  
 using 
  
 var 
  
 reader 
  
 = 
  
 await 
  
 createSelectCmd 
 . 
  ExecuteReaderAsync 
 
 (); 
  
 while 
  
 ( 
 await 
  
 reader 
 . 
  ReadAsync 
 
 ()) 
  
 { 
  
 Console 
 . 
 WriteLine 
 ( 
 $"{reader.GetFieldValue<string>(" 
 FirstName 
 ")}  {reader.GetFieldValue<string>(" 
 LastName 
 ")}" 
 ); 
  
 } 
  
 return 
  
 rowCount 
 ; 
  
 } 
 } 
 

  import 
  
 ( 
  
 "context" 
  
 "fmt" 
  
 "io" 
  
 "cloud.google.com/go/spanner" 
  
 "google.golang.org/api/iterator" 
 ) 
 func 
  
 writeAndReadUsingDML 
 ( 
 w 
  
 io 
 . 
 Writer 
 , 
  
 db 
  
 string 
 ) 
  
 error 
  
 { 
  
 ctx 
  
 := 
  
 context 
 . 
 Background 
 () 
  
 client 
 , 
  
 err 
  
 := 
  
 spanner 
 . 
 NewClient 
 ( 
 ctx 
 , 
  
 db 
 ) 
  
 if 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 err 
  
 } 
  
 defer 
  
 client 
 . 
 Close 
 () 
  
 _ 
 , 
  
 err 
  
 = 
  
 client 
 . 
 ReadWriteTransaction 
 ( 
 ctx 
 , 
  
 func 
 ( 
 ctx 
  
 context 
 . 
 Context 
 , 
  
 txn 
  
 * 
 spanner 
 . 
 ReadWriteTransaction 
 ) 
  
 error 
  
 { 
  
 // Insert Record 
  
 stmt 
  
 := 
  
 spanner 
 . 
  Statement 
 
 { 
  
 SQL 
 : 
  
 `INSERT Singers (SingerId, FirstName, LastName) 
 VALUES (11, 'Timothy', 'Campbell')` 
 , 
  
 } 
  
 rowCount 
 , 
  
 err 
  
 := 
  
 txn 
 . 
 Update 
 ( 
 ctx 
 , 
  
 stmt 
 ) 
  
 if 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 err 
  
 } 
  
 fmt 
 . 
 Fprintf 
 ( 
 w 
 , 
  
 "%d record(s) inserted.\n" 
 , 
  
 rowCount 
 ) 
  
 // Read newly inserted record 
  
 stmt 
  
 = 
  
 spanner 
 . 
  Statement 
 
 { 
 SQL 
 : 
  
 `SELECT FirstName, LastName FROM Singers WHERE SingerId = 11` 
 } 
  
 iter 
  
 := 
  
 txn 
 . 
 Query 
 ( 
 ctx 
 , 
  
 stmt 
 ) 
  
 defer 
  
 iter 
 . 
 Stop 
 () 
  
 for 
  
 { 
  
 row 
 , 
  
 err 
  
 := 
  
 iter 
 . 
 Next 
 () 
  
 if 
  
 err 
  
 == 
  
 iterator 
 . 
 Done 
  
 || 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 break 
  
 } 
  
 var 
  
 firstName 
 , 
  
 lastName 
  
 string 
  
 if 
  
 err 
  
 := 
  
 row 
 . 
  ColumnByName 
 
 ( 
 "FirstName" 
 , 
  
& firstName 
 ); 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 err 
  
 } 
  
 if 
  
 err 
  
 := 
  
 row 
 . 
  ColumnByName 
 
 ( 
 "LastName" 
 , 
  
& lastName 
 ); 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 err 
  
 } 
  
 fmt 
 . 
 Fprintf 
 ( 
 w 
 , 
  
 "Found record name with %s, %s" 
 , 
  
 firstName 
 , 
  
 lastName 
 ) 
  
 } 
  
 return 
  
 err 
  
 }) 
  
 return 
  
 err 
 } 
 

  static 
  
 void 
  
 writeAndReadUsingDml 
 ( 
 DatabaseClient 
  
 dbClient 
 ) 
  
 { 
  
 dbClient 
  
 . 
 readWriteTransaction 
 () 
  
 . 
 run 
 ( 
 transaction 
  
 - 
>  
 { 
  
 // Insert record. 
  
 String 
  
 sql 
  
 = 
  
 "INSERT INTO Singers (SingerId, FirstName, LastName) " 
  
 + 
  
 " VALUES (11, 'Timothy', 'Campbell')" 
 ; 
  
 long 
  
 rowCount 
  
 = 
  
 transaction 
 . 
 executeUpdate 
 ( 
 Statement 
 . 
 of 
 ( 
 sql 
 )); 
  
 System 
 . 
 out 
 . 
 printf 
 ( 
 "%d record inserted.\n" 
 , 
  
 rowCount 
 ); 
  
 // Read newly inserted record. 
  
 sql 
  
 = 
  
 "SELECT FirstName, LastName FROM Singers WHERE SingerId = 11" 
 ; 
  
 // We use a try-with-resource block to automatically release resources held by 
  
 // ResultSet. 
  
 try 
  
 ( 
 ResultSet 
  
 resultSet 
  
 = 
  
 transaction 
 . 
 executeQuery 
 ( 
 Statement 
 . 
 of 
 ( 
 sql 
 ))) 
  
 { 
  
 while 
  
 ( 
 resultSet 
 . 
 next 
 ()) 
  
 { 
  
 System 
 . 
 out 
 . 
 printf 
 ( 
  
 "%s %s\n" 
 , 
  
 resultSet 
 . 
 getString 
 ( 
 "FirstName" 
 ), 
  
 resultSet 
 . 
 getString 
 ( 
 "LastName" 
 )); 
  
 } 
  
 } 
  
 return 
  
 null 
 ; 
  
 }); 
 } 
 

  // Imports the Google Cloud client library 
 const 
  
 { 
 Spanner 
 } 
  
 = 
  
 require 
 ( 
 ' @google-cloud/spanner 
' 
 ); 
 /** 
 * TODO(developer): Uncomment the following lines before running the sample. 
 */ 
 // const projectId = 'my-project-id'; 
 // const instanceId = 'my-instance'; 
 // const databaseId = 'my-database'; 
 // Creates a client 
 const 
  
 spanner 
  
 = 
  
 new 
  
  Spanner 
 
 ({ 
  
 projectId 
 : 
  
 projectId 
 , 
 }); 
 // Gets a reference to a Cloud Spanner instance and database 
 const 
  
 instance 
  
 = 
  
 spanner 
 . 
 instance 
 ( 
 instanceId 
 ); 
 const 
  
 database 
  
 = 
  
 instance 
 . 
 database 
 ( 
 databaseId 
 ); 
 database 
 . 
  runTransaction 
 
 ( 
 async 
  
 ( 
 err 
 , 
  
 transaction 
 ) 
  
 = 
>  
 { 
  
 if 
  
 ( 
 err 
 ) 
  
 { 
  
 console 
 . 
 error 
 ( 
 err 
 ); 
  
 return 
 ; 
  
 } 
  
 try 
  
 { 
  
 await 
  
 transaction 
 . 
  runUpdate 
 
 ({ 
  
 sql 
 : 
  
 `INSERT Singers (SingerId, FirstName, LastName) 
 VALUES (11, 'Timothy', 'Campbell')` 
 , 
  
 }); 
  
 const 
  
 [ 
 rows 
 ] 
  
 = 
  
 await 
  
 transaction 
 . 
 run 
 ({ 
  
 sql 
 : 
  
 'SELECT FirstName, LastName FROM Singers' 
 , 
  
 }); 
  
 rows 
 . 
 forEach 
 ( 
 row 
  
 = 
>  
 { 
  
 const 
  
 json 
  
 = 
  
 row 
 . 
 toJSON 
 (); 
  
 console 
 . 
 log 
 ( 
 ` 
 ${ 
 json 
 . 
 FirstName 
 } 
  
 ${ 
 json 
 . 
 LastName 
 } 
 ` 
 ); 
  
 }); 
  
 await 
  
 transaction 
 . 
 commit 
 (); 
  
 } 
  
 catch 
  
 ( 
 err 
 ) 
  
 { 
  
 console 
 . 
 error 
 ( 
 'ERROR:' 
 , 
  
 err 
 ); 
  
 } 
  
 finally 
  
 { 
  
 // Close the database when finished. 
  
 database 
 . 
 close 
 (); 
  
 } 
 }); 
 

  use Google\Cloud\Spanner\SpannerClient; 
 use Google\Cloud\Spanner\Transaction; 
 /** 
 * Writes then reads data inside a Transaction with a DML statement. 
 * 
 * The database and table must already exist and can be created using 
 * `create_database`. 
 * Example: 
 * ``` 
 * insert_data($instanceId, $databaseId); 
 * ``` 
 * 
 * @param string $instanceId The Spanner instance ID. 
 * @param string $databaseId The Spanner database ID. 
 */ 
 function write_read_with_dml(string $instanceId, string $databaseId): void 
 { 
 $spanner = new SpannerClient(); 
 $instance = $spanner->instance($instanceId); 
 $database = $instance->database($databaseId); 
 $database->runTransaction(function (Transaction $t) { 
 $rowCount = $t->executeUpdate( 
 'INSERT Singers (SingerId, FirstName, LastName) ' 
 . " VALUES (11, 'Timothy', 'Campbell')"); 
 printf('Inserted %d row(s).' . PHP_EOL, $rowCount); 
 $results = $t->execute('SELECT FirstName, LastName FROM Singers WHERE SingerId = 11'); 
 foreach ($results as $row) { 
 printf('%s %s' . PHP_EOL, $row['FirstName'], $row['LastName']); 
 } 
 $t->commit(); 
 }); 
 } 
 

  # 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 INTO 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 
 ) 
 

  # project_id  = "Your Google Cloud project ID" 
 # instance_id = "Your Spanner instance ID" 
 # database_id = "Your Spanner database ID" 
 require 
  
 "google/cloud/spanner" 
 spanner 
  
 = 
  
 Google 
 :: 
 Cloud 
 :: 
  Spanner 
 
 . 
 new 
  
 project 
 : 
  
 project_id 
 client 
  
 = 
  
 spanner 
 . 
  client 
 
  
 instance_id 
 , 
  
 database_id 
 row_count 
  
 = 
  
 0 
 client 
 . 
 transaction 
  
 do 
  
 | 
 transaction 
 | 
  
 row_count 
  
 = 
  
 transaction 
 . 
  execute_update 
 
 ( 
  
 "INSERT INTO Singers (SingerId, FirstName, LastName) VALUES (11, 'Timothy', 'Campbell')" 
  
 ) 
  
 puts 
  
 " 
 #{ 
 row_count 
 } 
 record updated." 
  
 transaction 
 . 
 execute 
 ( 
 "SELECT FirstName, LastName FROM Singers WHERE SingerId = 11" 
 ) 
 . 
 rows 
 . 
  each 
 
  
 do 
  
 | 
 row 
 | 
  
 puts 
  
 " 
 #{ 
 row 
 [ 
 :FirstName 
 ] 
 } 
  
 #{ 
 row 
 [ 
 :LastName 
 ] 
 } 
 " 
  
 end 
 end