C# SQL增删查改

DBHelper:

/// <summary>
        /// 执行查询
        /// </summary>
        /// <param name="sql">有效的select语句</param>
        /// <returns>返回SqlDataReader</returns>
        public static SqlDataReader ExecuteReader(string sql)
        {
            SqlConnection con = new SqlConnection(constring);
            con.Open();
            SqlCommand cmd = new SqlCommand(sql, con);
            return cmd.ExecuteReader(CommandBehavior.CloseConnection);
        }
        /// <summary>
        /// 执行查询带参数
        /// </summary>
        /// <param name="sql">有效的select语句</param>
        /// <returns>返回SqlDataReader</returns>
        public static SqlDataReader ExecuteReader(string sql,SqlParameter parameter)
        {
            SqlConnection con = new SqlConnection(constring);
            con.Open();
            SqlCommand cmd = new SqlCommand(sql, con);
            cmd.Parameters.Add(parameter);
            return cmd.ExecuteReader(CommandBehavior.CloseConnection);
        }
        /// <summary>
        /// 执行查询带参数数组
        /// </summary>
        /// <param name="sql">有效的select语句</param>
        /// <returns>返回SqlDataReader</returns>
        public static SqlDataReader ExecuteReader(string sql, SqlParameter[] parameters)
        {
            SqlConnection con = new SqlConnection(constring);
            con.Open();
            SqlCommand cmd = new SqlCommand(sql, con);
            //AddRange添加数组
            cmd.Parameters.AddRange(parameters);
            return cmd.ExecuteReader(CommandBehavior.CloseConnection);
        }

        /// <summary>
        /// 执行增删改
        /// </summary>
        /// <param name="sql"></param>
        /// <returns>影响的行数</returns>
        public static int ExecuteNonQuery(string sql)
        {
            using (SqlConnection con = new SqlConnection(constring))
            {
                con.Open();
                SqlCommand cmd = new SqlCommand(sql, con);
                return cmd.ExecuteNonQuery();
            }
        }

        public static int ExecuteNonQuery(string sql,SqlParameter[] parameters)
        {
            using (SqlConnection con = new SqlConnection(constring))
            {
                con.Open();
                SqlCommand cmd = new SqlCommand(sql, con);
                //foreach (SqlParameter item in parameters)
                //{
                //    cmd.Parameters.Add(item);
                //}
                cmd.Parameters.AddRange(parameters);

                return cmd.ExecuteNonQuery();
            }
        }
        public static int ExecuteNonQuery(string sql, SqlParameter parameter)
        {
            using (SqlConnection con = new SqlConnection(constring))
            {
                con.Open();
                SqlCommand cmd = new SqlCommand(sql, con);
                cmd.Parameters.Add(parameter);
                return cmd.ExecuteNonQuery();
            }
        }

DAL:

public static int Insert(company model)
        {

            StringBuilder strSql = new StringBuilder();
            strSql.Append("insert into company");
            strSql.Append("(FullName,ShortName,Keywords,Description,Type,Property,Style,Capital,Size,Details,Province,City,Address,Postalcode,Tel,Fax,Mailbox,Url,Link,createtime,Poss,Linkman,Product,Userid)");
            strSql.Append(" values (");
           strSql.Append("@FullName,@ShortName,@Keywords,@Description,@Type,@Property,@Style,@Capital,@Size,@Details,@Province,@City,@Address,@Postalcode,@Tel,@Fax,@Mailbox,@Url,@Link,

@Createtime,@Poss,@Linkman,@Product,@Userid)");

//第一种：            

SqlParameter[] parameters =

{
             new SqlParameter("@FullName",SqlDbType.VarChar),
             new SqlParameter("@ShortName",SqlDbType.VarChar),
             new SqlParameter("@Keywords",SqlDbType.VarChar),
                                                   。。。。。。。。。。。。。。。。。。
 };

//第二种:

SqlParameter[] parameters = new SqlParameter[]{};

                                                parameters[].Value = model.FullName;
                                                parameters[].Value = ""; //model.ShortName;
                                                parameters[].Value = "";// model.Keywords;
                                                parameters[].Value = model.Description;
                                                parameters[].Value = model.Type;
                                                parameters[].Value = model.Property;
                                                parameters[].Value = model.Style;
                                                parameters[].Value = model.Capital;
                                                parameters[].Value = model.Size;
                                                //如果model.Details为空的话在执行的时候就会报“需要@Details参数，但未提供该参数”所以不能parameters[9].Value = model.Details;这样写
                                                parameters[].Value = model.Details == null ? (object)System.DBNull.Value : model.Details;
                                                //parameters[9].Value = model.Details;
                                                。。。。。。。。。。。。。。。。。。。
            return DBHelper.ExecuteNonQuery(strSql.ToString(), parameters);
        }

public static List<company> SelectTop5(string type)
        {

            //asp.net SqlParameter关于Like的传参数无效问题问题在于Sql给参数自动添加了单引号。实际上在Sql，将like的代码解析成为了like '%'type'%' ",所以要写成下面的形式
            string sql = "select top 5 * from company where poss='通过' and type like @type order by createtime desc";
            string seach = "%"+type+"%";
            SqlDataReader reader = DBHelper.ExecuteReader(sql, new SqlParameter("@type",ObjToStr(seach)));
    。。。。。。。。。。。。。。。。。。。
}