Add Rows.TypeMap.

fbxpool/rows.go

@@ -3,6 +3,7 @@ package fbxpool
 import (
 	"github.com/firebirdsql/fbx"
 	"github.com/firebirdsql/fbx/fbconn"
+	"github.com/firebirdsql/fbx/fbtype"
 )
 
 type errRows struct {
@@ -18,6 +19,7 @@ func (e errRows) Scan(dest ...any) error                     { return e.err }
 func (e errRows) Values() ([]any, error)                     { return nil, e.err }
 func (e errRows) RawValues() [][]byte                        { return nil }
 func (e errRows) Conn() *fbx.Conn                            { return nil }
+func (e errRows) TypeMap() *fbtype.Map                       { return nil }
 
 type errRow struct {
 	err error
@@ -90,6 +92,10 @@ func (rows *poolRows) Conn() *fbx.Conn {
 	return rows.r.Conn()
 }
 
+func (rows *poolRows) TypeMap() *fbtype.Map {
+	return rows.r.TypeMap()
+}
+
 type poolRow struct {
 	r   fbx.Row
 	c   *Conn

rows.go

@@ -74,6 +74,11 @@ type Rows interface {
 	// Conn returns the underlying *Conn on which the query was executed. This may return nil if Rows did not come from a
 	// *Conn (e.g. if it was created by RowsFromResultReader)
 	Conn() *Conn
+
+	// TypeMap returns the [fbtype.Map] the values of this Rows are decoded with. It is available even when [Rows.Conn]
+	// is nil, such as for a Rows created by [RowsFromResultReader]. It may return nil if the Rows carries no values,
+	// such as one representing only an error.
+	TypeMap() *fbtype.Map
 }
 
 // Row is a convenience wrapper over Rows that is returned by QueryRow.
@@ -424,6 +429,10 @@ func (rows *baseRows) Conn() *Conn {
 	return rows.conn
 }
 
+func (rows *baseRows) TypeMap() *fbtype.Map {
+	return rows.typeMap
+}
+
 func (rows *baseRows) scanBlobValue(fd *fbconn.FieldDescription, src []byte, dst any) error {
 	if src == nil {
 		switch d := dst.(type) {

rows_test.go

@@ -11,6 +11,7 @@ import (
 	"github.com/firebirdsql/fbx"
 	"github.com/firebirdsql/fbx/fbconn"
 	"github.com/firebirdsql/fbx/fbproto"
+	"github.com/firebirdsql/fbx/fbtype"
 	"github.com/firebirdsql/fbx/fbxtest"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -1320,3 +1321,27 @@ recreate table products (
 	// Fries: $5
 	// Soft Drink: $3
 }
+
+// Rows.TypeMap is available even when Rows.Conn is nil, so a caller can decode raw values itself.
+func TestRowsTypeMapWithoutConn(t *testing.T) {
+	t.Parallel()
+
+	defaultConnTestRunner.RunTest(context.Background(), t, func(ctx context.Context, t testing.TB, conn *fbx.Conn) {
+		rr := conn.FbConn().Exec(ctx, `select cast('Adam' as varchar(5)) as name from rdb$database`)
+
+		rows := fbx.RowsFromResultReader(conn.TypeMap(), rr)
+		defer func() {
+			rows.Close()
+			require.NoError(t, rows.Err())
+		}()
+		require.Nil(t, rows.Conn(), "this Rows has no Conn, which is what makes TypeMap necessary")
+		require.Same(t, conn.TypeMap(), rows.TypeMap())
+
+		require.True(t, rows.Next())
+		fd := rows.FieldDescriptions()[0]
+		var name string
+		typeMetadata := fbtype.NewTypeMetadata(fd.Type, fd.Subtype, fd.Length, fd.Scale)
+		require.NoError(t, rows.TypeMap().Scan(typeMetadata, rows.RawValues()[0], &name))
+		require.Equal(t, "Adam", name)
+	})
+}