Add Scan and Value to pgtype.Multirange[T]

pgtype/multirange.go

@@ -441,3 +441,50 @@ func (r Multirange[T]) ScanIndex(i int) any {
 func (r Multirange[T]) ScanIndexType() any {
 	return new(T)
 }
+
+// Scan implements the database/sql Scanner interface.
+//
+// Range needs a *Map to decode the range elements. Unfortunately, the the Go type system does not support attaching
+// data to a type and the Scanner interface does not have an argument that can be used to pass extra data to the Scan
+// method. To work around this limitation, Scan uses a default *Map. This means Scan may only work properly with types
+// that are supported by a default *Map. from a Map or Codec.
+func (r *Multirange[T]) Scan(v any) error {
+	if v == nil {
+		*r = nil
+		return nil
+	}
+
+	m := databaseSQLMapPool.Get().(*Map)
+	defer databaseSQLMapPool.Put(m)
+
+	switch v := v.(type) {
+	case string:
+		return m.Scan(0, 0, []byte(v), r)
+	case []byte:
+		return m.Scan(0, 0, v, r)
+	default:
+		return fmt.Errorf("unsupported type: %T", v)
+	}
+}
+
+// Value implements the database/sql/driver Valuer interface.
+//
+// Range needs a *Map to encode the range elements. Unfortunately, the the Go type system does not support attaching
+// data to a type and the Valuer interface does not have an argument that can be used to pass extra data to the Value
+// method. To work around this limitation, Value uses a default *Map. This means Value may only work properly with types
+// that are supported by a default *Map. from a Map or Codec.
+func (src Multirange[T]) Value() (driver.Value, error) {
+	if src == nil {
+		return nil, nil
+	}
+
+	m := databaseSQLMapPool.Get().(*Map)
+	defer databaseSQLMapPool.Put(m)
+
+	buf, err := m.Encode(0, TextFormatCode, src, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	return string(buf), nil
+}

stdlib/sql_test.go

@@ -584,6 +584,44 @@ func TestConnQueryPGTypeRange(t *testing.T) {
 	})
 }
 
+func TestConnQueryPGTypeMultirange(t *testing.T) {
+	testWithAllQueryExecModes(t, func(t *testing.T, db *sql.DB) {
+		skipCockroachDB(t, db, "Server does not support int4range")
+
+		var r pgtype.Multirange[pgtype.Range[pgtype.Int4]]
+		err := db.QueryRow("select int4multirange(int4range(1, 5), int4range(7,9))").Scan(&r)
+		require.NoError(t, err)
+		assert.Equal(
+			t,
+			pgtype.Multirange[pgtype.Range[pgtype.Int4]]{
+				{
+					Lower:     pgtype.Int4{Int32: 1, Valid: true},
+					Upper:     pgtype.Int4{Int32: 5, Valid: true},
+					LowerType: pgtype.Inclusive,
+					UpperType: pgtype.Exclusive,
+					Valid:     true,
+				},
+				{
+					Lower:     pgtype.Int4{Int32: 7, Valid: true},
+					Upper:     pgtype.Int4{Int32: 9, Valid: true},
+					LowerType: pgtype.Inclusive,
+					UpperType: pgtype.Exclusive,
+					Valid:     true,
+				},
+			},
+			r)
+
+		var equal bool
+		err = db.QueryRow("select int4multirange(int4range(1, 5), int4range(7,9)) = $1::int4multirange", r).Scan(&equal)
+		require.NoError(t, err)
+		require.Equal(t, true, equal)
+
+		err = db.QueryRow("select null::int4multirange").Scan(&r)
+		require.NoError(t, err)
+		require.Nil(t, r)
+	})
+}
+
 // Test type that pgx would handle natively in binary, but since it is not a
 // database/sql native type should be passed through as a string
 func TestConnQueryRowPgxBinary(t *testing.T) {