Add RowScanner interface

CHANGELOG.md

@@ -120,6 +120,10 @@ See documentation for `QueryExecMode`.
 
 pgx now supports named arguments with the NamedArgs type. This is implemented via the new QueryRewriter interface which
 allows arbitrary rewriting of query SQL and arguments.
+
+## RowScanner Interface
+
+The `RowScanner` interface allows a single argument to Rows.Scan to scan the entire row.
 ## 3rd Party Logger Integration
 
 All integrations with 3rd party loggers have been extracted to separate repositories. This trims the pgx dependency

rows.go

@@ -69,6 +69,12 @@ type Row interface {
 	Scan(dest ...any) error
 }
 
+// RowScanner scans an entire row at a time into the RowScanner.
+type RowScanner interface {
+	// ScanRows scans the row.
+	ScanRow(rows Rows) error
+}
+
 // connRow implements the Row interface for Conn.QueryRow.
 type connRow connRows
 
@@ -212,6 +218,13 @@ func (rows *connRows) Scan(dest ...any) error {
 		rows.fatal(err)
 		return err
 	}
+
+	if len(dest) == 1 {
+		if rc, ok := dest[0].(RowScanner); ok {
+			return rc.ScanRow(rows)
+		}
+	}
+
 	if len(fieldDescriptions) != len(dest) {
 		err := fmt.Errorf("number of field descriptions must equal number of destinations, got %d and %d", len(fieldDescriptions), len(dest))
 		rows.fatal(err)

rows_test.go

@@ -0,0 +1,30 @@
+package pgx_test
+
+import (
+	"context"
+	"testing"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/stretchr/testify/require"
+)
+
+type testRowScanner struct {
+	name string
+	age  int32
+}
+
+func (rs *testRowScanner) ScanRow(rows pgx.Rows) error {
+	return rows.Scan(&rs.name, &rs.age)
+}
+
+func TestRowScanner(t *testing.T) {
+	t.Parallel()
+
+	defaultConnTestRunner.RunTest(context.Background(), t, func(ctx context.Context, t testing.TB, conn *pgx.Conn) {
+		var s testRowScanner
+		err := conn.QueryRow(ctx, "select 'Adam' as name, 72 as height").Scan(&s)
+		require.NoError(t, err)
+		require.Equal(t, "Adam", s.name)
+		require.Equal(t, int32(72), s.age)
+	})
+}