Batch read data

Usage notes

A single batch read request can return up to 100 rows.

Prerequisites

Initialize a Tablestore client

Method

func (tableStoreClient *TableStoreClient) BatchGetRow(request *BatchGetRowRequest) (*BatchGetRowResponse, error)

Sample code

The following example reads two rows whose primary keys are row1 and row2 from the test_table table.

func BatchGetRowSample(client *tablestore.TableStoreClient) {
    // Construct the query criteria.
    multiRowQueryCriteria := new(tablestore.MultiRowQueryCriteria)
    // Set the table name.
    multiRowQueryCriteria.TableName = "test_table"
    // Add the primary key for the first row.
    getPk1 := new(tablestore.PrimaryKey)
    getPk1.AddPrimaryKeyColumn("id", "row1")
    multiRowQueryCriteria.AddRow(getPk1)
    // Add the primary key for the second row.
    getPk2 := new(tablestore.PrimaryKey)
    getPk2.AddPrimaryKeyColumn("id", "row2")
    multiRowQueryCriteria.AddRow(getPk2)
    // Set the maximum number of versions to return.
    multiRowQueryCriteria.MaxVersion = 1

    // Call the BatchGetRow method.
    batchGetRowRequest := new(tablestore.BatchGetRowRequest)
    batchGetRowRequest.MultiRowQueryCriteria = append(batchGetRowRequest.MultiRowQueryCriteria, multiRowQueryCriteria)
    batchGetRowResponse, err := client.BatchGetRow(batchGetRowRequest)

    // Process the response.
    if err != nil {
        fmt.Println("Batch get row failed with error: ", err)
    } else {
        fmt.Printf("* RequestId: %s \n", batchGetRowResponse.RequestId)
        for tableName, rows := range batchGetRowResponse.TableToRowsResult {
            fmt.Printf("* Table: %s \n", tableName)
            for _, row := range rows {
                if row.IsSucceed {
                    fmt.Printf("Succeeded Row: %v \n", row)
                } else {
                    fmt.Printf("Failed Row: %d | %v \n", row.Index, row.Error)
                }
            }
        }
    }
}

The following snippets show how to set optional batch read parameters.

• To read from multiple tables in one request, add a separate MultiRowQueryCriteria object for each table.

  // Construct the query criteria for the second table.
  multiRowQueryCriteria1 := new(tablestore.MultiRowQueryCriteria)
  multiRowQueryCriteria1.TableName = "orders_small"
  // Add the primary key for the first row.
  getPk3 := new(tablestore.PrimaryKey)
  getPk3.AddPrimaryKeyColumn("order_id", "90fb478c-1360-11f0-a34d-00163e30a2a9")
  multiRowQueryCriteria1.AddRow(getPk3)
  // Set the maximum number of versions to return.
  multiRowQueryCriteria1.MaxVersion = 1
  // Add the MultiRowQueryCriteria object to the request.
  batchGetRowRequest.MultiRowQueryCriteria = append(batchGetRowRequest.MultiRowQueryCriteria, multiRowQueryCriteria1)

• To limit reads to a specific version range, set TimeRange. Only data within the specified range is returned.

  // Set the version range to the last 24 hours.
  timeRange := new(tablestore.TimeRange)
  timeRange.Start = int64(time.Now().Unix() * 1000 - 86400 * 1000) 
  timeRange.End = int64(time.Now().Unix() * 1000) 
  multiRowQueryCriteria.TimeRange = timeRange

• Specify specific attribute columns to read.

  multiRowQueryCriteria.AddColumnToGet("col1")

Related topics

Read data within a range