c#简单更新查询不工作

SqlConnection conn = new SqlConnection(@"Data Source=SAI'SQLEXPRESS;Initial Catalog=testing;Integrated Security=True;Pooling=False");
conn.Open();
SqlCommand command = new SqlCommand();
string test = "UPDATE attend Year='2014' WHERE Id = '2'";
command = new SqlCommand(test, conn);
command.ExecuteNonQuery();
conn.Close();

Year和id都是varchar。错误:

'Year'附近语法错误。