Add driver.RowsColumnTypeDatabaseTypeName support to stdlib.Rows

stdlib/sql.go

@@ -71,6 +71,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"strings"
 	"sync"
 
 	"github.com/jackc/pgx"
@@ -405,6 +406,10 @@ func (r *Rows) Columns() []string {
 	return names
 }
 
+func (r *Rows) ColumnTypeDatabaseTypeName(index int) string {
+	return strings.ToUpper(r.rows.FieldDescriptions()[index].DataTypeName)
+}
+
 func (r *Rows) Close() error {
 	r.rows.Close()
 	return nil

stdlib/sql_test.go

@@ -1073,3 +1073,30 @@ func TestConnQueryContextCancel(t *testing.T) {
 		t.Errorf("mock server err: %v", err)
 	}
 }
+
+func TestRowsColumnTypeDatabaseTypeName(t *testing.T) {
+	db := openDB(t)
+	defer closeDB(t, db)
+
+	rows, err := db.Query("select * from generate_series(1,10) n")
+	if err != nil {
+		t.Fatalf("db.Query failed: %v", err)
+	}
+
+	columnTypes, err := rows.ColumnTypes()
+	if err != nil {
+		t.Fatalf("rows.ColumnTypes failed: %v", err)
+	}
+
+	if len(columnTypes) != 1 {
+		t.Fatalf("len(columnTypes) => %v, want %v", len(columnTypes), 1)
+	}
+
+	if columnTypes[0].DatabaseTypeName() != "INT4" {
+		t.Errorf("columnTypes[0].DatabaseTypeName() => %v, want %v", columnTypes[0].DatabaseTypeName(), "INT4")
+	}
+
+	rows.Close()
+
+	ensureConnValid(t, db)
+}