无法将int类型转换为system.data.datatable

namespace LoginDAL
{
public class DAL:LoginIDAL.IDAL
{

    public DataTable selectUser(LoginEntity.UserInfo UserInfo)
    {
        SQLHelper.SQLHelper  sqlHelper = new SQLHelper.SQLHelper();
        SqlParameter[] sqlParams = { new SqlParameter("@userID", UserInfo.ID), new SqlParameter("@PassWord", UserInfo.PassWord) };
        string sql = @"SELECT * FROM [User_Info] WHERE UserID=@UserID and PWD =@PassWord";

         DataTable   table = sqlHelper.ExeculteNonQuery(sql, sqlParams, CommandType.Text); 这句报错无法将int类型转换为system.data.datatable
        return table;