Tablestore:Hapus data

Hapus satu baris

• Hapus satu baris

  Kode contoh berikut menunjukkan cara menghapus satu baris data dari tabel:

  private static void deleteRow(SyncClient client, String pkValue) {
      // Construct the primary key. 
      PrimaryKeyBuilder primaryKeyBuilder = PrimaryKeyBuilder.createPrimaryKeyBuilder();
      primaryKeyBuilder.addPrimaryKeyColumn("pk", PrimaryKeyValue.fromString(pkValue));
      PrimaryKey primaryKey = primaryKeyBuilder.build();
      // Specify the name of the data table. 
      RowDeleteChange rowDeleteChange = new RowDeleteChange("<TABLE_NAME>", primaryKey);
  
      client.deleteRow(new DeleteRowRequest(rowDeleteChange));
  }                    

• Gunakan kondisi untuk menghapus satu baris

  Kode contoh berikut menunjukkan cara menghapus satu baris data dari tabel data ketika baris tersebut ada dan nilai kolom Col0 pada baris tersebut lebih besar dari 100:

  private static void deleteRow(SyncClient client, String pkValue) {
      // Construct the primary key. 
      PrimaryKeyBuilder primaryKeyBuilder = PrimaryKeyBuilder.createPrimaryKeyBuilder();
      primaryKeyBuilder.addPrimaryKeyColumn("pk", PrimaryKeyValue.fromString(pkValue));
      PrimaryKey primaryKey = primaryKeyBuilder.build();
      // Specify the name of the data table. 
      RowDeleteChange rowDeleteChange = new RowDeleteChange("<TABLE_NAME>", primaryKey);
  
      // Specify conditions for the DeleteRow operation. In this example, a row is deleted only when the row exists and the value of the Col0 column is greater than 100. 
      Condition condition = new Condition(RowExistenceExpectation.EXPECT_EXIST);
      condition.setColumnCondition(new SingleColumnValueCondition("Col0",
              SingleColumnValueCondition.CompareOperator.GREATER_THAN, ColumnValue.fromLong(100)));
      rowDeleteChange.setCondition(condition);
  
      client.deleteRow(new DeleteRowRequest(rowDeleteChange));
  }                   

Hapus beberapa baris

1. Sebelum menghapus data, pilih metode untuk mengambil kunci primer dari baris yang ingin dihapus.

   • Untuk menghapus baris dalam rentang kunci primer tertentu, gunakan operasi GetRange untuk mengambil kunci primernya. Untuk informasi selengkapnya, lihat Read data.

   • Untuk menghapus baris yang memenuhi kriteria tertentu, buat indeks pencarian. Lalu, gunakan indeks pencarian tersebut untuk mengkueri data dan mengambil kunci primer dari baris yang akan dihapus. Untuk informasi selengkapnya, lihat Create a search index dan Use an SDK to query data with a search index.

2. Setelah Anda memiliki kunci primernya, panggil operasi BatchWriteRow untuk menghapus baris-baris tersebut. Untuk informasi selengkapnya, lihat Batch write data.

   Kode contoh berikut menunjukkan cara menghapus satu baris data di mana nilai kolom kunci primer pk adalah pk dari satu tabel data, dan satu baris data lain di mana nilai kolom kunci primer pk1 adalah pk1 dan nilai kolom kunci primer pk2 adalah pk2 dari tabel data lain secara bersamaan:

   private static void batchWriteRow(SyncClient client) {    
       BatchWriteRowRequest batchWriteRowRequest = new BatchWriteRowRequest();
   
       // Construct rowDeleteChange1. 
       PrimaryKeyBuilder pk1Builder = PrimaryKeyBuilder.createPrimaryKeyBuilder();
       pk1Builder.addPrimaryKeyColumn("pk", PrimaryKeyValue.fromString("pk"));
       // Specify the name of the data table. 
       RowDeleteChange rowDeleteChange1 = new RowDeleteChange("<TABLE_NAME1>", pk1Builder.build());
       // Add rowDeleteChange1 to the code of the batch operation. 
       batchWriteRowRequest.addRowChange(rowDeleteChange1);
   
       // Construct rowDeleteChange2. 
       PrimaryKeyBuilder pk2Builder = PrimaryKeyBuilder.createPrimaryKeyBuilder();
       pk2Builder.addPrimaryKeyColumn("pk1", PrimaryKeyValue.fromString("pk1"));
       pk2Builder.addPrimaryKeyColumn("pk2", PrimaryKeyValue.fromString("pk2"));
       // Specify the name of the data table. 
       RowDeleteChange rowDeleteChange2 = new RowDeleteChange("<TABLE_NAME2>", pk2Builder.build());
       // Add rowDeleteChange2 to the code of the batch operation. 
       batchWriteRowRequest.addRowChange(rowDeleteChange2);
   
       BatchWriteRowResponse response = client.batchWriteRow(batchWriteRowRequest);
   
       System.out.println("Whether all operations are successful:" + response.isAllSucceed());
       if (!response.isAllSucceed()) {
           for (BatchWriteRowResponse.RowResult rowResult : response.getFailedRows()) {
               System.out.println("Failed rows:" + batchWriteRowRequest.getRowChange(rowResult.getTableName(), rowResult.getIndex()).getPrimaryKey());
               System.out.println("Cause of failures:" + rowResult.getError());
           }
           /**
            * You can use the createRequestForRetry method to construct another request to retry the operations on failed rows. In this example, only the retry request is constructed. 
            * We recommend that you use the custom retry policy in Tablestore SDKs as the retry method. This feature allows you to retry failed rows after batch operations are performed. After you specify the retry policy, you do not need to add retry code to call the operation. 
            */
           BatchWriteRowRequest retryRequest = batchWriteRowRequest.createRequestForRetry(response.getFailedRows());
       }
   }