Query a column-based time-partitioned table

  import 
  
 ( 
  
 "context" 
  
 "fmt" 
  
 "io" 
  
 "cloud.google.com/go/bigquery" 
  
 "google.golang.org/api/iterator" 
 ) 
 // queryPartitionedTable demonstrates querying a time partitioned table and using a predicate that 
 // leverages the partitioned column. 
 func 
  
 queryPartitionedTable 
 ( 
 w 
  
 io 
 . 
 Writer 
 , 
  
 projectID 
 , 
  
 datasetID 
 , 
  
 tableID 
  
 string 
 ) 
  
 error 
  
 { 
  
 // projectID := "my-project-id" 
  
 // datasetID := "mydataset" 
  
 // tableID := "mytable" 
  
 ctx 
  
 := 
  
 context 
 . 
 Background 
 () 
  
 client 
 , 
  
 err 
  
 := 
  
 bigquery 
 . 
 NewClient 
 ( 
 ctx 
 , 
  
 projectID 
 ) 
  
 if 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 fmt 
 . 
 Errorf 
 ( 
 "bigquery.NewClient: %w" 
 , 
  
 err 
 ) 
  
 } 
  
 defer 
  
 client 
 . 
 Close 
 () 
  
 q 
  
 := 
  
 client 
 . 
 Query 
 ( 
 fmt 
 . 
 Sprintf 
 ( 
 "SELECT * FROM `%s.%s` WHERE `date` BETWEEN DATE('1800-01-01') AND DATE('1899-12-31')" 
 , 
  
 datasetID 
 , 
  
 tableID 
 )) 
  
 // Run the query and process the returned row iterator. 
  
 it 
 , 
  
 err 
  
 := 
  
 q 
 . 
 Read 
 ( 
 ctx 
 ) 
  
 if 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 fmt 
 . 
 Errorf 
 ( 
 "query.Read(): %w" 
 , 
  
 err 
 ) 
  
 } 
  
 for 
  
 { 
  
 var 
  
 row 
  
 [] 
 bigquery 
 . 
  Value 
 
  
 err 
  
 := 
  
 it 
 . 
 Next 
 ( 
& row 
 ) 
  
 if 
  
 err 
  
 == 
  
 iterator 
 . 
 Done 
  
 { 
  
 break 
  
 } 
  
 if 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 err 
  
 } 
  
 fmt 
 . 
 Fprintln 
 ( 
 w 
 , 
  
 row 
 ) 
  
 } 
  
 return 
  
 nil 
 } 
 

  import 
  
 com.google.cloud.bigquery. BigQuery 
 
 ; 
 import 
  
 com.google.cloud.bigquery. BigQueryException 
 
 ; 
 import 
  
 com.google.cloud.bigquery. BigQueryOptions 
 
 ; 
 import 
  
 com.google.cloud.bigquery. QueryJobConfiguration 
 
 ; 
 import 
  
 com.google.cloud.bigquery. QueryParameterValue 
 
 ; 
 import 
  
 com.google.cloud.bigquery. TableResult 
 
 ; 
 // Sample to run query on partitioned table. 
 public 
  
 class 
 QueryPartitionedTable 
  
 { 
  
 public 
  
 static 
  
 void 
  
 main 
 ( 
 String 
 [] 
  
 args 
 ) 
  
 { 
  
 // TODO(developer): Replace these variables before running the sample. 
  
 String 
  
 datasetName 
  
 = 
  
 "MY_DATASET_NAME" 
 ; 
  
 String 
  
 tableName 
  
 = 
  
 "MY_TABLE_NAME" 
 ; 
  
 String 
  
 query 
  
 = 
  
 String 
 . 
 format 
 ( 
  
 "SELECT * FROM `%s.%s` WHERE date BETWEEN @start_date AND @end_date" 
 , 
  
 datasetName 
 , 
  
 tableName 
 ); 
  
 queryPartitionedTable 
 ( 
 query 
 ); 
  
 } 
  
 public 
  
 static 
  
 void 
  
 queryPartitionedTable 
 ( 
 String 
  
 query 
 ) 
  
 { 
  
 try 
  
 { 
  
 // Initialize client that will be used to send requests. This client only needs to be created 
  
 // once, and can be reused for multiple requests. 
  
  BigQuery 
 
  
 bigquery 
  
 = 
  
  BigQueryOptions 
 
 . 
 getDefaultInstance 
 (). 
 getService 
 (); 
  
  QueryJobConfiguration 
 
  
 queryConfig 
  
 = 
  
  QueryJobConfiguration 
 
 . 
 newBuilder 
 ( 
 query 
 ) 
  
 . 
  addNamedParameter 
 
 ( 
 "start_date" 
 , 
  
  QueryParameterValue 
 
 . 
  date 
 
 ( 
 "1800-01-01" 
 )) 
  
 . 
  addNamedParameter 
 
 ( 
 "end_date" 
 , 
  
  QueryParameterValue 
 
 . 
  date 
 
 ( 
 "1899-12-31" 
 )) 
  
 . 
 build 
 (); 
  
  TableResult 
 
  
 results 
  
 = 
  
 bigquery 
 . 
  query 
 
 ( 
 queryConfig 
 ); 
  
 results 
  
 . 
  iterateAll 
 
 () 
  
 . 
 forEach 
 ( 
 row 
  
 - 
>  
 row 
 . 
 forEach 
 ( 
 val 
  
 - 
>  
 System 
 . 
 out 
 . 
 printf 
 ( 
 "%s," 
 , 
  
 val 
 . 
 toString 
 ()))); 
  
 System 
 . 
 out 
 . 
 println 
 ( 
 "Query partitioned table performed successfully." 
 ); 
  
 } 
  
 catch 
  
 ( 
  BigQueryException 
 
  
 | 
  
 InterruptedException 
  
 e 
 ) 
  
 { 
  
 System 
 . 
 out 
 . 
 println 
 ( 
 "Query not performed \n" 
  
 + 
  
 e 
 . 
 toString 
 ()); 
  
 } 
  
 } 
 }