Tablestore:Batch read data

Usage notes

A single batch read operation can read up to 100 rows.

Prerequisites

Initialize the Tablestore client

Method signature

public BatchGetRowResponse BatchGetRow(BatchGetRowRequest request)

Asynchronous method:

public Task<BatchGetRowResponse> BatchGetRowAsync(BatchGetRowRequest request)

Examples

The following code example shows how to read two rows of data whose primary key values are row1 and row2 from the test_table table.

try
{
    List<PrimaryKey> primaryKeys = new List<PrimaryKey>
    {
        // Add the primary key of the first row.
        new PrimaryKey {{ "id", new ColumnValue("row1") }},
        // Add the primary key of the second row.
        new PrimaryKey {{ "id", new ColumnValue("row2") }},
    };

    // Construct the query criteria.
    BatchGetRowRequest batchGetRowRequest = new BatchGetRowRequest();
    batchGetRowRequest.Add("test_table", primaryKeys);

    // Call the BatchGetRow method to read row data.
    BatchGetRowResponse batchGetRowResponse = client.BatchGetRow(batchGetRowRequest);

    // Process the response.
    Console.WriteLine($"* RequestId: {batchGetRowResponse.RequestID}");
    Console.WriteLine($"* Is all succeeded: {batchGetRowResponse.IsAllSucceed}");
    foreach (var tableGroup in batchGetRowResponse.RowDataGroupByTable)
    {
        Console.WriteLine($"* Table: {tableGroup.Key}");
        foreach (var item in tableGroup.Value)
        {
            if (item.IsOK)
            {
                if (item.Row != null)
                {
                    Console.WriteLine($"Succeeded Row: {item.Row}");
                }
                else
                {
                    Console.WriteLine("Succeeded Row: This row does not exist.");
                }
            }
            else
            {
                Console.WriteLine($"Failed Row: {item.ErrorMessage}");
            }
        }
    }
}
catch (Exception ex)
{
    Console.WriteLine($"Batch get row failed, exception: {ex.Message}");
}

The following examples show how to configure parameters for a batch read data operation.

• To read data from multiple tables in a single batch read operation, you must specify a MultiRowQueryCriteria for each table.

  // Construct the query criteria for the second table.
  List<PrimaryKey> primaryKeys1 = new List<PrimaryKey>
  {
      new PrimaryKey {{ "order_id", new ColumnValue("90fb478c-1360-11f0-a34d-00163e30a2a9") }}
  };
  
  batchGetRowRequest.Add("orders_small", primaryKeys1);

• Specify the attribute columns to read.

  HashSet<string> columnsToGet = new HashSet<string> { "col2" };
  
  batchGetRowRequest.Add("test_table", primaryKeys, columnsToGet);