Query data with index

  void 
  
 QueryUsingIndex 
 ( 
 google 
 :: 
 cloud 
 :: 
 spanner 
 :: 
 Client 
  
 client 
 ) 
  
 { 
  
 namespace 
  
 spanner 
  
 = 
  
 :: 
 google 
 :: 
 cloud 
 :: 
 spanner 
 ; 
  
 spanner 
 :: 
 SqlStatement 
  
 select 
 ( 
  
 "SELECT AlbumId, AlbumTitle, MarketingBudget" 
  
 " FROM Albums@{FORCE_INDEX=AlbumsByAlbumTitle}" 
  
 " WHERE AlbumTitle >= @start_title AND AlbumTitle < @end_title" 
 , 
  
{{"start_title", spanner::Value("Aardvark")},
       {"end_title", spanner::Value("Goo")} }); 
  
 using 
  
 RowType 
  
 = 
  
 std 
 :: 
 tuple<std 
 :: 
 int64_t 
 , 
  
 std 
 :: 
 string 
 , 
  
 absl 
 :: 
 optional<std 
 :: 
 int64_t 
>> ; 
  
 auto 
  
 rows 
  
 = 
  
 client 
 . 
 ExecuteQuery 
 ( 
 std 
 :: 
 move 
 ( 
 select 
 )); 
  
 for 
  
 ( 
 auto 
&  
 row 
  
 : 
  
 spanner 
 :: 
 StreamOf<RowType> 
 ( 
 rows 
 )) 
  
 { 
  
 if 
  
 ( 
 ! 
 row 
 ) 
  
 throw 
  
 std 
 :: 
 move 
 ( 
 row 
 ). 
 status 
 (); 
  
 std 
 :: 
 cout 
 << 
 "AlbumId: " 
 << 
 std 
 :: 
 get<0> 
 ( 
 * 
 row 
 ) 
 << 
 " 
 \t 
 " 
 ; 
  
 std 
 :: 
 cout 
 << 
 "AlbumTitle: " 
 << 
 std 
 :: 
 get<1> 
 ( 
 * 
 row 
 ) 
 << 
 " 
 \t 
 " 
 ; 
  
 auto 
  
 marketing_budget 
  
 = 
  
 std 
 :: 
 get<2> 
 ( 
 * 
 row 
 ); 
  
 if 
  
 ( 
 marketing_budget 
 ) 
  
 { 
  
 std 
 :: 
 cout 
 << 
 "MarketingBudget: " 
 << 
 * 
 marketing_budget 
 << 
 " 
 \n 
 " 
 ; 
  
 } 
  
 else 
  
 { 
  
 std 
 :: 
 cout 
 << 
 "MarketingBudget: NULL 
 \n 
 " 
 ; 
  
 } 
  
 } 
  
 std 
 :: 
 cout 
 << 
 "Read completed for [spanner_query_data_with_index] 
 \n 
 " 
 ; 
 } 
 

  using 
  
  Google.Cloud.Spanner.Data 
 
 ; 
 using 
  
 System.Collections.Generic 
 ; 
 using 
  
 System.Threading.Tasks 
 ; 
 public 
  
 class 
  
 QueryDataWithIndexAsyncSample 
 { 
  
 public 
  
 class 
  
 Album 
  
 { 
  
 public 
  
 int 
  
 AlbumId 
  
 { 
  
 get 
 ; 
  
 set 
 ; 
  
 } 
  
 public 
  
 string 
  
 AlbumTitle 
  
 { 
  
 get 
 ; 
  
 set 
 ; 
  
 } 
  
 public 
  
 long 
  
 MarketingBudget 
  
 { 
  
 get 
 ; 
  
 set 
 ; 
  
 } 
  
 } 
  
 public 
  
 async 
  
 Task<List<Album> 
>  
 QueryDataWithIndexAsync 
 ( 
 string 
  
 projectId 
 , 
  
 string 
  
 instanceId 
 , 
  
 string 
  
 databaseId 
 , 
  
 string 
  
 startTitle 
 , 
  
 string 
  
 endTitle 
 ) 
  
 { 
  
 string 
  
 connectionString 
  
 = 
  
 $"Data Source=projects/{projectId}/instances/{instanceId}/databases/{databaseId}" 
 ; 
  
 using 
  
 var 
  
 connection 
  
 = 
  
 new 
  
  SpannerConnection 
 
 ( 
 connectionString 
 ); 
  
 using 
  
 var 
  
 cmd 
  
 = 
  
 connection 
 . 
  CreateSelectCommand 
 
 ( 
  
 "SELECT AlbumId, AlbumTitle, MarketingBudget FROM Albums@ " 
  
 + 
  
 "{FORCE_INDEX=AlbumsByAlbumTitle} " 
  
 + 
  
 $"WHERE AlbumTitle >= @startTitle " 
  
 + 
  
 $"AND AlbumTitle < @endTitle" 
 , 
  
 new 
  
  SpannerParameterCollection 
 
  
 { 
  
 { 
  
 "startTitle" 
 , 
  
  SpannerDbType 
 
 . 
  String 
 
 , 
  
 startTitle 
  
 }, 
  
 { 
  
 "endTitle" 
 , 
  
  SpannerDbType 
 
 . 
  String 
 
 , 
  
 endTitle 
  
 } 
  
 }); 
  
 var 
  
 albums 
  
 = 
  
 new 
  
 List<Album> 
 (); 
  
 using 
  
 var 
  
 reader 
  
 = 
  
 await 
  
 cmd 
 . 
  ExecuteReaderAsync 
 
 (); 
  
 while 
  
 ( 
 await 
  
 reader 
 . 
  ReadAsync 
 
 ()) 
  
 { 
  
 albums 
 . 
 Add 
 ( 
 new 
  
 Album 
  
 { 
  
 AlbumId 
  
 = 
  
 reader 
 . 
 GetFieldValue<int> 
 ( 
 "AlbumId" 
 ), 
  
 AlbumTitle 
  
 = 
  
 reader 
 . 
 GetFieldValue<string> 
 ( 
 "AlbumTitle" 
 ), 
  
 MarketingBudget 
  
 = 
  
 reader 
 . 
  IsDBNull 
 
 ( 
 reader 
 . 
  GetOrdinal 
 
 ( 
 "MarketingBudget" 
 )) 
  
 ? 
  
 0 
  
 : 
  
 reader 
 . 
 GetFieldValue<long> 
 ( 
 "MarketingBudget" 
 ) 
  
 }); 
  
 } 
  
 return 
  
 albums 
 ; 
  
 } 
 } 
 

  import 
  
 ( 
  
 "context" 
  
 "fmt" 
  
 "io" 
  
 "strconv" 
  
 "cloud.google.com/go/spanner" 
  
 "google.golang.org/api/iterator" 
 ) 
 func 
  
 queryUsingIndex 
 ( 
 w 
  
 io 
 . 
 Writer 
 , 
  
 db 
  
 string 
 ) 
  
 error 
  
 { 
  
 ctx 
  
 := 
  
 context 
 . 
 Background 
 () 
  
 client 
 , 
  
 err 
  
 := 
  
 spanner 
 . 
 NewClient 
 ( 
 ctx 
 , 
  
 db 
 ) 
  
 if 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 err 
  
 } 
  
 defer 
  
 client 
 . 
 Close 
 () 
  
 stmt 
  
 := 
  
 spanner 
 . 
  Statement 
 
 { 
  
 SQL 
 : 
  
 `SELECT AlbumId, AlbumTitle, MarketingBudget 
 FROM Albums@{FORCE_INDEX=AlbumsByAlbumTitle} 
 WHERE AlbumTitle >= @start_title AND AlbumTitle < @end_title` 
 , 
  
 Params 
 : 
  
 map 
 [ 
 string 
 ] 
 interface 
 {}{ 
  
 "start_title" 
 : 
  
 "Aardvark" 
 , 
  
 "end_title" 
 : 
  
 "Goo" 
 , 
  
 }, 
  
 } 
  
 iter 
  
 := 
  
 client 
 . 
  Single 
 
 (). 
 Query 
 ( 
 ctx 
 , 
  
 stmt 
 ) 
  
 defer 
  
 iter 
 . 
 Stop 
 () 
  
 for 
  
 { 
  
 row 
 , 
  
 err 
  
 := 
  
 iter 
 . 
 Next 
 () 
  
 if 
  
 err 
  
 == 
  
 iterator 
 . 
 Done 
  
 { 
  
 break 
  
 } 
  
 if 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 err 
  
 } 
  
 var 
  
 albumID 
  
 int64 
  
 var 
  
 marketingBudget 
  
 spanner 
 . 
  NullInt64 
 
  
 var 
  
 albumTitle 
  
 string 
  
 if 
  
 err 
  
 := 
  
 row 
 . 
  ColumnByName 
 
 ( 
 "AlbumId" 
 , 
  
& albumID 
 ); 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 err 
  
 } 
  
 if 
  
 err 
  
 := 
  
 row 
 . 
  ColumnByName 
 
 ( 
 "AlbumTitle" 
 , 
  
& albumTitle 
 ); 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 err 
  
 } 
  
 if 
  
 err 
  
 := 
  
 row 
 . 
  ColumnByName 
 
 ( 
 "MarketingBudget" 
 , 
  
& marketingBudget 
 ); 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 err 
  
 } 
  
 budget 
  
 := 
  
 "NULL" 
  
 if 
  
 marketingBudget 
 . 
 Valid 
  
 { 
  
 budget 
  
 = 
  
 strconv 
 . 
 FormatInt 
 ( 
 marketingBudget 
 . 
  Int64 
 
 , 
  
 10 
 ) 
  
 } 
  
 fmt 
 . 
 Fprintf 
 ( 
 w 
 , 
  
 "%d %s %s\n" 
 , 
  
 albumID 
 , 
  
 albumTitle 
 , 
  
 budget 
 ) 
  
 } 
  
 return 
  
 nil 
 } 
 

  static 
  
 void 
  
 queryUsingIndex 
 ( 
 DatabaseClient 
  
 dbClient 
 ) 
  
 { 
  
 Statement 
  
 statement 
  
 = 
  
 Statement 
  
 // We use FORCE_INDEX hint to specify which index to use. For more details see 
  
 // https://cloud.google.com/spanner/docs/query-syntax#from-clause 
  
 . 
 newBuilder 
 ( 
  
 "SELECT AlbumId, AlbumTitle, MarketingBudget " 
  
 + 
  
 "FROM Albums@{FORCE_INDEX=AlbumsByAlbumTitle} " 
  
 + 
  
 "WHERE AlbumTitle >= @StartTitle AND AlbumTitle < @EndTitle" 
 ) 
  
 // We use @BoundParameters to help speed up frequently executed queries. 
  
 //  For more details see https://cloud.google.com/spanner/docs/sql-best-practices 
  
 . 
 bind 
 ( 
 "StartTitle" 
 ) 
  
 . 
 to 
 ( 
 "Aardvark" 
 ) 
  
 . 
 bind 
 ( 
 "EndTitle" 
 ) 
  
 . 
 to 
 ( 
 "Goo" 
 ) 
  
 . 
 build 
 (); 
  
 try 
  
 ( 
 ResultSet 
  
 resultSet 
  
 = 
  
 dbClient 
 . 
 singleUse 
 (). 
 executeQuery 
 ( 
 statement 
 )) 
  
 { 
  
 while 
  
 ( 
 resultSet 
 . 
 next 
 ()) 
  
 { 
  
 System 
 . 
 out 
 . 
 printf 
 ( 
  
 "%d %s %s\n" 
 , 
  
 resultSet 
 . 
 getLong 
 ( 
 "AlbumId" 
 ), 
  
 resultSet 
 . 
 getString 
 ( 
 "AlbumTitle" 
 ), 
  
 resultSet 
 . 
 isNull 
 ( 
 "MarketingBudget" 
 ) 
  
 ? 
  
 "NULL" 
  
 : 
  
 resultSet 
 . 
 getLong 
 ( 
 "MarketingBudget" 
 )); 
  
 } 
  
 } 
 } 
 

  /** 
 * TODO(developer): Uncomment these variables before running the sample. 
 */ 
 // const instanceId = 'my-instance'; 
 // const databaseId = 'my-database'; 
 // const projectId = 'my-project-id'; 
 // const startTitle = 'Ardvark'; 
 // const endTitle = 'Goo'; 
 // Imports the Google Cloud Spanner client library 
 const 
  
 { 
 Spanner 
 } 
  
 = 
  
 require 
 ( 
 ' @google-cloud/spanner 
' 
 ); 
 // Instantiates a client 
 const 
  
 spanner 
  
 = 
  
 new 
  
  Spanner 
 
 ({ 
  
 projectId 
 : 
  
 projectId 
 , 
 }); 
 async 
  
 function 
  
 queryDataWithIndex 
 () 
  
 { 
  
 // Gets a reference to a Cloud Spanner instance and database 
  
 const 
  
 instance 
  
 = 
  
 spanner 
 . 
 instance 
 ( 
 instanceId 
 ); 
  
 const 
  
 database 
  
 = 
  
 instance 
 . 
 database 
 ( 
 databaseId 
 ); 
  
 const 
  
 query 
  
 = 
  
 { 
  
 sql 
 : 
  
 `SELECT AlbumId, AlbumTitle, MarketingBudget 
 FROM Albums@{FORCE_INDEX=AlbumsByAlbumTitle} 
 WHERE AlbumTitle >= @startTitle AND AlbumTitle <= @endTitle` 
 , 
  
 params 
 : 
  
 { 
  
 startTitle 
 : 
  
 startTitle 
 , 
  
 endTitle 
 : 
  
 endTitle 
 , 
  
 }, 
  
 }; 
  
 // Queries rows from the Albums table 
  
 try 
  
 { 
  
 const 
  
 [ 
 rows 
 ] 
  
 = 
  
 await 
  
 database 
 . 
 run 
 ( 
 query 
 ); 
  
 rows 
 . 
 forEach 
 ( 
 row 
  
 = 
>  
 { 
  
 const 
  
 json 
  
 = 
  
 row 
 . 
 toJSON 
 (); 
  
 const 
  
 marketingBudget 
  
 = 
  
 json 
 . 
 MarketingBudget 
  
 ? 
  
 json 
 . 
 MarketingBudget 
  
 : 
  
 null 
 ; 
  
 // This value is nullable 
  
 console 
 . 
 log 
 ( 
  
 `AlbumId: 
 ${ 
 json 
 . 
 AlbumId 
 } 
 , AlbumTitle: 
 ${ 
 json 
 . 
 AlbumTitle 
 } 
 , MarketingBudget: 
 ${ 
 marketingBudget 
 } 
 ` 
 , 
  
 ); 
  
 }); 
  
 } 
  
 catch 
  
 ( 
 err 
 ) 
  
 { 
  
 console 
 . 
 error 
 ( 
 'ERROR:' 
 , 
  
 err 
 ); 
  
 } 
  
 finally 
  
 { 
  
 // Close the database when finished. 
  
 database 
 . 
 close 
 (); 
  
 } 
 } 
 queryDataWithIndex 
 (); 
 

  use Google\Cloud\Spanner\SpannerClient; 
 /** 
 * 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) 
 * 
 * Example: 
 * ``` 
 * query_data_with_index($instanceId, $databaseId); 
 * ``` 
 * 
 * @param string $instanceId The Spanner instance ID. 
 * @param string $databaseId The Spanner database ID. 
 * @param string $startTitle The start of the title index. 
 * @param string $endTitle   The end of the title index. 
 */ 
 function query_data_with_index( 
 string $instanceId, 
 string $databaseId, 
 string $startTitle = 'Aardvark', 
 string $endTitle = 'Goo' 
 ): void { 
 $spanner = new SpannerClient(); 
 $instance = $spanner->instance($instanceId); 
 $database = $instance->database($databaseId); 
 $parameters = [ 
 'startTitle' => $startTitle, 
 'endTitle' => $endTitle 
 ]; 
 $results = $database->execute( 
 'SELECT AlbumId, AlbumTitle, MarketingBudget ' . 
 'FROM Albums@{FORCE_INDEX=AlbumsByAlbumTitle} ' . 
 'WHERE AlbumTitle >= @startTitle AND AlbumTitle < @endTitle', 
 ['parameters' => $parameters] 
 ); 
 foreach ($results as $row) { 
 printf('AlbumId: %s, AlbumTitle: %s, MarketingBudget: %d' . PHP_EOL, 
 $row['AlbumId'], $row['AlbumTitle'], $row['MarketingBudget']); 
 } 
 } 
 

  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 
 """ 
 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" 
 : 
 spanner 
 . 
 param_types 
 . 
 STRING 
 , 
 "end_title" 
 : 
 spanner 
 . 
 param_types 
 . 
 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 
 ( 
 "AlbumId: 
 {} 
 , AlbumTitle: 
 {} 
 , " 
 "MarketingBudget: 
 {} 
 " 
 . 
 format 
 ( 
 * 
 row 
 )) 
 

  # project_id  = "Your Google Cloud project ID" 
 # instance_id = "Your Spanner instance ID" 
 # database_id = "Your Spanner database ID" 
 # start_title = "An album title to start with such as 'Ardvark'" 
 # end_title   = "An album title to end with such as 'Goo'" 
 require 
  
 "google/cloud/spanner" 
 spanner 
  
 = 
  
 Google 
 :: 
 Cloud 
 :: 
  Spanner 
 
 . 
 new 
  
 project 
 : 
  
 project_id 
 client 
  
 = 
  
 spanner 
 . 
  client 
 
  
 instance_id 
 , 
  
 database_id 
 sql_query 
  
 = 
  
 "SELECT AlbumId, AlbumTitle, MarketingBudget 
 FROM Albums@{FORCE_INDEX=AlbumsByAlbumTitle} 
 WHERE AlbumTitle >= @start_title AND AlbumTitle < @end_title" 
 params 
  
 = 
  
 { 
  
 start_title 
 : 
  
 start_title 
 , 
  
 end_title 
 : 
  
 end_title 
  
 } 
 param_types 
  
 = 
  
 { 
  
 start_title 
 : 
  
 :STRING 
 , 
  
 end_title 
 : 
  
 :STRING 
  
 } 
 client 
 . 
 execute 
 ( 
 sql_query 
 , 
  
 params 
 : 
  
 params 
 , 
  
 types 
 : 
  
 param_types 
 ) 
 . 
 rows 
 . 
  each 
 
  
 do 
  
 | 
 row 
 | 
  
 puts 
  
 " 
 #{ 
 row 
 [ 
 :AlbumId 
 ] 
 } 
  
 #{ 
 row 
 [ 
 :AlbumTitle 
 ] 
 } 
  
 #{ 
 row 
 [ 
 :MarketingBudget 
 ] 
 } 
 " 
 end