Tablestore Go SDK configure auto-increment primary key column - Tablestore

This topic describes how to configure an auto-increment primary key column for a table, write data to an auto-increment column, and obtain the generated auto-increment values using the Tablestore SDK for Go.

Considerations

The auto-increment values generated for an auto-increment column are unique and strictly monotonically increasing at the partition key level, but are not guaranteed to be consecutive.

Prerequisites

Initialize an OTSClient instance.

Configure an auto-increment primary key column

You can set a non-partition primary key column to auto-increment when creating a table, but you cannot do so for an existing table.

Note

Only integer non-partition primary key columns can be auto-increment columns. A table can have at most one auto-increment column, which generates 64-bit signed integer values.

Sample code

The following sample code creates a table named test_table. The primary key of the table includes the partition key id and the auto-increment column incr.

func CreateTableSample(client *tablestore.TableStoreClient) {
    tableMeta := new(tablestore.TableMeta)
    tableMeta.TableName = "test_table"
    tableMeta.AddPrimaryKeyColumn("id", tablestore.PrimaryKeyType_STRING)
    tableMeta.AddPrimaryKeyColumnOption("incr", tablestore.PrimaryKeyType_INTEGER, tablestore.AUTO_INCREMENT)

    tableOption := new(tablestore.TableOption)
    tableOption.MaxVersion = 1
    tableOption.TimeToAlive = -1

    reservedThroughput := new(tablestore.ReservedThroughput)

    createTableRequest := new(tablestore.CreateTableRequest)
    createTableRequest.TableMeta = tableMeta
    createTableRequest.TableOption = tableOption
    createTableRequest.ReservedThroughput = reservedThroughput
    _, err := client.CreateTable(createTableRequest)
    if err != nil {
        fmt.Println("Failed to create table with error:", err)
    } else {
        fmt.Println("Create table finished.")
    }
}

Write data

When writing data to an auto-increment column, you must set a value placeholder. To obtain the generated auto-increment value for queries and updates, set the return type of putRowChange to ReturnType_RT_PK.

Sample code

The following sample code writes a row of data to the test_table table, obtains the primary key information of the written row, and prints it.

func PutRowSample(client *tablestore.TableStoreClient) {
    // Construct the primary key
    putPrimaryKey := new(tablestore.PrimaryKey)
    putPrimaryKey.AddPrimaryKeyColumn("id", "row1")
    // Set the auto-increment column
    putPrimaryKey.AddPrimaryKeyColumnWithAutoIncrement("incr")

    // Construct the row data to write
    putRowChange := new(tablestore.PutRowChange)
    putRowChange.TableName = "test_table"
    putRowChange.PrimaryKey = putPrimaryKey
    putRowChange.AddColumn("col1", "val1")
    putRowChange.SetCondition(tablestore.RowExistenceExpectation_IGNORE)
    // Set the return type to ReturnType_RT_PK to return the primary key information of the written row
    putRowChange.ReturnType = tablestore.ReturnType_RT_PK

    // Call the putRow method to write the row data
    putRowRequest := new(tablestore.PutRowRequest)
    putRowRequest.PutRowChange = putRowChange
    response, err := client.PutRow(putRowRequest)
    if err != nil {
        fmt.Println("Failed to put row with error:", err)
    } else {
        // RequestId and consumed CU
        fmt.Printf("RequestId: %s \n", response.RequestId)
        fmt.Printf("Read CU Cost: %d \n", response.ConsumedCapacityUnit.Read)
        fmt.Printf("Write CU Cost: %d \n", response.ConsumedCapacityUnit.Write)

        // Get and print the returned primary key information. If the return type is not set to ReturnType_RT_PK, the primary key information is not returned by default
        fmt.Println(response.PrimaryKey)
    }
}