用三层架构写查询多个和单个

 

DAL

//查询name 查询多个的
public static List<ClassInfo> Select(string name="")
{
var sql = $"select * from classinfo where name like @name";
SqlParameter[] sqlParameters = new SqlParameter[] {
new SqlParameter("@name",$"%{name}%")
};
DataTable table = Class1.Query(sql,sqlParameters);
List<ClassInfo> list = new List<ClassInfo>();
foreach (DataRow row in table.Rows)
{
var cls = new ClassInfo()
{
Id = Convert.ToInt32(row["Id"]),
Name=Convert.ToString(row["Name"]),
Content = Convert.ToString(row["Content"])
};
list.Add(cls);
}
return list;
}
//public static int Delete(int id)
//{
// var sql = $"delete from ClassInfo where id={id}";
// return Class1.NonQuery(sql);
//}
//查询ID 查询单个
public static ClassInfo Select(int id)
{
var sql = "select * from classinfo where id=@id";
SqlParameter[] sqlParameters = new SqlParameter[]
{
new SqlParameter("@id",id)
};
SqlDataReader reader = Class1.Reader(sql, sqlParameters);
ClassInfo info = null;
if (reader.Read())
{
info = new ClassInfo()
{
Id = Convert.ToInt32(reader["Id"]),
Name = Convert.ToString(reader["Name"]),
Content = Convert.ToString(reader["Content"])
};
}
reader.Close();
return info;

}
}

BLL

public static List<ClassInfo> Select(string name = "")
{
return ClassInfoDAL.Select(name);
}
public static ClassInfo Select(int id)
{
return ClassInfoDAL.Select(id);
}

 

主项目 Test  ClassInfo.aspx

前台：--.aspx

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" CellPadding="4" ForeColor="#333333" GridLines="None">
<AlternatingRowStyle BackColor="White" />
<Columns>
<asp:BoundField DataField="Id" HeaderText="编号" />
<asp:BoundField DataField="Name" HeaderText="班级名" />
<asp:BoundField DataField="Content" HeaderText="内容" />
<asp:HyperLinkField Text="详情" DataNavigateUrlFields="Id" DataNavigateUrlFormatString="ClassInfoDetial.aspx?id={0}"/>
</Columns>

后台：---.aspx.cs

GridView1.DataSource = ClassInfoBLL.Select();
GridView1.DataBind();

 

前台----ClassInfoDetial

<div>
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</div>

后台----ClassInfoDetial.aspx.cs

int id = Convert.ToInt32(Request.QueryString["id"]);
model.ClassInfo info = ClassInfoBLL.Select(id);
if (info!=null)
{
Label1.Text = info.Name;
}