Aggregation API

type Client interface {
    // NewAggExecutor create an aggregate executor.
    NewAggExecutor(tableName string, rangePairs []*table.RangePair, opts ...option.ObQueryOption) AggExecutor
}

type AggExecutor interface {
    // Min add a min operation to the agg executor.
    Min(columnName string) AggExecutor
    // Max add a max operation to the agg executor.
    Max(columnName string) AggExecutor
    // Count add a count operation to the agg executor.
    Count() AggExecutor
    // Sum add a sum operation to the agg executor.
    Sum(columnName string) AggExecutor
    // Avg add an avg operation to the agg executor.
    Avg(columnName string) AggExecutor
    // Execute an agg operation.
    // AggregateResult contains the results of all operations.
    Execute(ctx context.Context) (AggregateResult, error)
}

func main() {
    const (
        configUrl    = "xxx"
        fullUserName = "user@tenant#cluster"
        passWord     = ""
        sysUserName  = "sysUser"
        sysPassWord  = ""
        tableName    = "test"
    )
    cfg := config.NewDefaultClientConfig()
    cli, err := client.NewClient(configUrl, fullUserName, passWord, sysUserName, sysPassWord, cfg)
    if err != nil {
        panic(err)
    }

    startRowKey := []*table.Column{table.NewColumn("c1", int64(0)), table.NewColumn("c2", table.Min)}
    endRowKey := []*table.Column{table.NewColumn("c1", int64(100)), table.NewColumn("c2", table.Max)}
    keyRanges := []*table.RangePair{table.NewRangePair(startRowKey, endRowKey)}

    // create agg executor
    aggExecutor := cli.NewAggExecutor(tableName, keyRanges).Sum("c3").Min("c2").Max("c1").Count()

    // get agg result
    res, err := aggExecutor.Execute(context.TODO())

    if err != nil {
        panic(err)
    }

    // get agg result value
    println(res.Value("sum(c3)").(int64))
    println(res.Value("min(c2)").(int64))
    println(res.Value("max(c1)").(int64))
    println(res.Value("count(*)").(int64))
}