Merge pull request #1081 from ydb-platform/indexed-scanner

added implementation of indexed scanner

Author: asmyasnikov

internal/query/column.go

@@ -32,7 +32,7 @@ func executeQueryRequest(a *allocator.Allocator, sessionID, q string, settings e
 	request.SessionId = sessionID
 	request.ExecMode = Ydb_Query.ExecMode(settings.ExecMode())
 	request.TxControl = settings.TxControl().ToYDB(a)
-	request.Query = queryFromText(a, q, settings.Syntax())
+	request.Query = queryFromText(a, q, Ydb_Query.Syntax(settings.Syntax()))
 	request.Parameters = settings.Params().ToYDB(a)
 	request.StatsMode = Ydb_Query.StatsMode(settings.StatsMode())
 	request.ConcurrentResultSets = false

internal/query/execute_query.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io"
 
+	"github.com/ydb-platform/ydb-go-genproto/protos/Ydb"
 	"github.com/ydb-platform/ydb-go-genproto/protos/Ydb_Query"
 
 	"github.com/ydb-platform/ydb-go-sdk/v3/internal/xerrors"
@@ -16,7 +17,7 @@ var _ query.ResultSet = (*resultSet)(nil)
 type resultSet struct {
 	index       int64
 	recv        func() (*Ydb_Query.ExecuteQueryResponsePart, error)
-	columns     []query.Column
+	columns     []*Ydb.Column
 	currentPart *Ydb_Query.ExecuteQueryResponsePart
 	rowIndex    int
 	done        chan struct{}
@@ -33,7 +34,7 @@ func newResultSet(
 		recv:        recv,
 		currentPart: part,
 		rowIndex:    -1,
-		columns:     newColumns(part.GetResultSet().GetColumns()),
+		columns:     part.GetResultSet().GetColumns(),
 		done:        make(chan struct{}),
 	}
 }

internal/query/result_set.go

@@ -14,7 +14,7 @@ type row struct {
 	scannerStruct
 }
 
-func newRow(columns []query.Column, v *Ydb.Value) (*row, error) {
+func newRow(columns []*Ydb.Column, v *Ydb.Value) (*row, error) {
 	data := newScannerData(columns, v.GetItems())
 
 	return &row{

internal/query/row.go

@@ -2,16 +2,14 @@ package query
 
 import (
 	"github.com/ydb-platform/ydb-go-genproto/protos/Ydb"
-
-	"github.com/ydb-platform/ydb-go-sdk/v3/query"
 )
 
 type scannerData struct {
-	columns []query.Column
+	columns []*Ydb.Column
 	values  []*Ydb.Value
 }
 
-func newScannerData(columns []query.Column, values []*Ydb.Value) *scannerData {
+func newScannerData(columns []*Ydb.Column, values []*Ydb.Value) *scannerData {
 	return &scannerData{
 		columns: columns,
 		values:  values,

internal/query/scanner_data.go

@@ -1,6 +1,10 @@
 package query
 
 import (
+	"fmt"
+	"reflect"
+
+	"github.com/ydb-platform/ydb-go-sdk/v3/internal/value"
 	"github.com/ydb-platform/ydb-go-sdk/v3/internal/xerrors"
 	"github.com/ydb-platform/ydb-go-sdk/v3/query"
 )
@@ -22,5 +26,24 @@ func (s scannerIndexed) Scan(dst ...interface{}) error {
 		return xerrors.WithStackTrace(errWrongArgumentsCount)
 	}
 
-	return xerrors.WithStackTrace(ErrNotImplemented)
+	for i := range dst {
+		v := value.FromYDB(s.data.columns[i].GetType(), s.data.values[i])
+		if err := value.CastTo(v, dst[i]); err != nil {
+			to := reflect.ValueOf(dst[i])
+			if to.Kind() != reflect.Pointer {
+				return xerrors.WithStackTrace(
+					fmt.Errorf("dst[%d] type is not a pointer ('%s')", i,
+						to.Kind().String(),
+					))
+			}
+			vv := reflect.ValueOf(v)
+			if vv.CanConvert(to.Elem().Type()) {
+				to.Elem().Set(vv.Convert(to.Elem().Type()))
+			} else {
+				return xerrors.WithStackTrace(err)
+			}
+		}
+	}
+
+	return nil
 }