拼凑sql语句另外一个方法

static void Main(string[] args)
{
var dict = new Dictionary<string, string>();
dict["username"] = "Yuhao";
dict["password"] = "abc@123";

var sq = dict.Aggregate("select * from users where 1=1", (current, param) => Addparam(current, param.Key, param.Value));
Console.WriteLine(sq);
Console.Read();
}

private static string Addparam(string rawValue, string key, string value)
{

return rawValue = rawValue + " and " + key + "='" + value + "'";
}