Multiple-row operations

The Table Store SDK provides the following multi-row operation APIs: BatchGetRow, BatchWriteRow, GetRange, and GetByIterator.

BatchGetRow

Reads several data rows in batches from one or more tables.

The BatchGetRow operation can be viewed as a set of multiple GetRow operations. Each operation is executed, results are returned, and capacity units are consumed independently.

Compared to the execution of a large number of GetRow operations, the BatchGetRow operation effectively reduces the request response time and increases the data read rate.

API

    //Return multiple data rows in a table
    //
    // @param BatchGetRowRequest             Encapsulate the parameters required to perform the BatchGetRow operation
    // @return  BatchGetRowResponse          Content of the response to the BatchGetRow operation
    BatchGetRow(request *BatchGetRowRequest) (*BatchGetRowResponse, error)

Example

Read 10 data rows in batches.

batchGetReq := &tablestore.BatchGetRowRequest{}
mqCriteria := &tablestore.MultiRowQueryCriteria{}
for i := 0; i < 10; i++ {
    pkToGet := new(tablestore.PrimaryKey)
    pkToGet.AddPrimaryKeyColumn("pk1", "pk1value1")
    pkToGet.AddPrimaryKeyColumn("pk2", int64(i))
    pkToGet.AddPrimaryKeyColumn("pk3", []byte("pk3"))
    mqCriteria.AddRow(pkToGet)
    mqCriteria.MaxVersion = 1
}
mqCriteria.TableName = tableName
batchGetReq.MultiRowQueryCriteria = append(batchGetReq.MultiRowQueryCriteria, mqCriteria)
batchGetResponse, err := client.BatchGetRow(batchGetReq)
if err != nil {
    fmt.Println("batachget failed with error:", err)
} else {
    fmt.Println("batchget finished")
}

Note:

• BatchGetRow supports filtering using conditional statements.
• Obtain the full sample codes at BatchGetRow@GitHub.

BatchWriteRow

Inserts, modifies, or deletes several data rows in batches in one or more tables. It is essentially a set of multiple PutRow, UpdateRow, and DeleteRow operations. Each operation is executed, results are returned independently, and capacity units are consumed independently.

API

    // Add, delete, or modify multiple data rows in multiple tables
    //
    // @param BatchWriteRowRequest             Encapsulate the parameters required to perform the BatchWriteRow operation
    // @return  BatchWriteRowResponse          Content of the response to the BatchWriteRow operation
    BatchWriteRow(request *BatchWriteRowRequest) (*BatchWriteRowResponse,error)

Example

Write 100 data rows in batches.

    batchWriteReq := &tablestore.BatchWriteRowRequest{}
    for i := 0; i < 100; i++ {
        putRowChange := new(tablestore.PutRowChange)
        putRowChange.TableName = tableName
        putPk := new(tablestore.PrimaryKey)
        putPk.AddPrimaryKeyColumn("pk1", "pk1value1")
        putPk.AddPrimaryKeyColumn("pk2", int64(i))
        putPk.AddPrimaryKeyColumn("pk3", []byte("pk3"))
        putRowChange.PrimaryKey = putPk
        putRowChange.AddColumn("col1", "fixvalue")
        putRowChange.SetCondition(tablestore.RowExistenceExpectation_IGNORE)
        batchWriteReq.AddRowChange(putRowChange)
    }
    response, err := client.BatchWriteRow(batchWriteReq)
    if err != nil {
        fmt.Println("batch request failed with:", response)
    } else {
        fmt.Println("batch write row finished")
    }

Note:

• BatchWriteRow supports filtering using conditional statements.
• Obtain the full sample codes at BatchWriteRow@GitHub.

GetRange

This API reads data within the specified primary key range.

API

    // Read multiple data rows within the specified range in a table.
    //
    // @param GetRangeRequest            Encapsulate the parameters required to perform the GetRange operation
    // @return GetRangeResponse          Content of the response to the GetRange operation
    GetRange(request *GetRangeRequest) (*GetRangeResponse,error)

Example

Read data within the specified range.

getRangeRequest := &tablestore.GetRangeRequest{}
    rangeRowQueryCriteria := &tablestore.RangeRowQueryCriteria{}
    rangeRowQueryCriteria.TableName = tableName
    startPK := new(tablestore.PrimaryKey)
    startPK.AddPrimaryKeyColumnWithMinValue("pk1")
    startPK.AddPrimaryKeyColumnWithMinValue("pk2")
    startPK.AddPrimaryKeyColumnWithMinValue("pk3")
    endPK := new(tablestore.PrimaryKey)
    endPK.AddPrimaryKeyColumnWithMaxValue("pk1")
    endPK.AddPrimaryKeyColumnWithMaxValue("pk2")
    endPK.AddPrimaryKeyColumnWithMaxValue("pk3")
    rangeRowQueryCriteria.StartPrimaryKey = startPK
    rangeRowQueryCriteria.EndPrimaryKey = endPK
    rangeRowQueryCriteria.Direction = tablestore.FORWARD
    rangeRowQueryCriteria.MaxVersion = 1
    rangeRowQueryCriteria.Limit = 10
    getRangeRequest.RangeRowQueryCriteria = rangeRowQueryCriteria
    getRangeResp, err := client.GetRange(getRangeRequest)
    fmt.Println("get range result is " ,getRangeResp)
    for ; ; {
        if err != nil {
            fmt.Println("get range failed with error:", err)
        }
        if (len(getRangeResp.Rows) > 0) {
            for _, row := range getRangeResp.Rows {
                fmt.Println("range get row with key", row.PrimaryKey.PrimaryKeys[0].Value, row.PrimaryKey.PrimaryKeys[1].Value, row.PrimaryKey.PrimaryKeys[2].Value)
            }
            if getRangeResp.NextStartPrimaryKey == nil {
                break
            } else {
                fmt.Println("next pk is :", getRangeResp.NextStartPrimaryKey.PrimaryKeys[0].Value, getRangeResp.NextStartPrimaryKey.PrimaryKeys[1].Value, getRangeResp.NextStartPrimaryKey.PrimaryKeys[2].Value)
                getRangeRequest.RangeRowQueryCriteria.StartPrimaryKey = getRangeResp.NextStartPrimaryKey
                getRangeResp, err = client.GetRange(getRangeRequest)
            }
        } else {
            break
        }
        fmt.Println("continue to query rows")
    }
    fmt.Println("putrow finished")

Note:

• GetRange supports filtering using conditional statements.
• When performing the GetRange operation, note that the data may be paged.
• Obtain the full sample codes at GetRange@GitHub.