1.把数据库里面的数据显示出来
sqlHelper怎么用:[网上可以下载,需要可以找楼主要]
1.拷贝到项目,修改它的命名空间等于当前项目名称
2.数据库的连接信息,用户名,密码,登录方式等
<connectionStrings>
<add name="con" connectionString="Database=mySchool;Server=.;Integrated Security=false;Uid=sa;Password=123456;" providerName="System.Data.SqlClient"/>
</connectionStrings>
1 // 1.怎么运用sqlhelper得到一个数据表,用一个变量存储起来2 string strsql = "select NewsId,title,newsclass,ViewCount from RNews where 1=1";3 //2.找到数据库里sql语句对应的数据库表,一个dataset里有多个数据表4 DataTable dt=SqlHelper.ExecuteDataSetText(strsql,null).Tables[0];5 GridView1.DataSource = dt;6 GridView1.DataBind();
html,前端页面,用于接收数据的页面
1 <div id="gvRnews"> 2 <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"> 3 <Columns> 4 <asp:BoundField DataField="NewsId" HeaderText="编号" /> 5 <asp:BoundField DataField="title" HeaderText="标题" /> 6 <asp:BoundField DataField="newsclass" HeaderText="班级" /> 7 <asp:BoundField DataField="ViewCount" HeaderText="浏览数" /> 8 </Columns> 9 </asp:GridView>10 </div>
这样结果就出来啦:
2.通过标题和分类进行查询显示:
html部分代码:
1 <div id="gvSelect"> 2 <table> 3 <tr> 4 <td>标题:</td> 5 <td> 6 <asp:TextBox ID="txtSTitle" runat="server"></asp:TextBox> 7 </td> 8 <td>分类:</td> 9 <td>10 <asp:DropDownList ID="ddlSNewsClass" runat="server">11 <asp:ListItem>--请选择--</asp:ListItem>12 <asp:ListItem>首页焦点</asp:ListItem>13 <asp:ListItem>业务信息</asp:ListItem>14 <asp:ListItem>学员感言</asp:ListItem>15 <asp:ListItem>常见问题</asp:ListItem>16 </asp:DropDownList>17 </td>18 <td>19 <asp:Button ID="btnSelect" runat="server" Text="查询" OnClick="btnSelect_Click" />20 </td>21 </tr>22 </table>23 </div>
后台.cs代码,加上where 1=1的原因是为了什么条件下sql语句都正确,这很重要,不加的前提条件是它两都不能为空
1 protected void Page_Load(object sender, EventArgs e) 2 { 3 BindRnews(); 4 } 5 //写在一个方法里,用的时候直接调用该方法 6 public void BindRnews() 7 { 8 //1.怎么运用sqlhelper得到一个数据表,用一个变量存储起来 9 string strsql = GetStrSql();10 //2.找到数据库里sql语句对应的数据库表11 DataTable dt = SqlHelper.ExecuteDataSetText(strsql, null).Tables[0];12 GridView1.DataSource = dt;13 GridView1.DataBind();14 }15 public string GetStrSql() 16 {17 StringBuilder sb = new StringBuilder();18 sb.Append("select NewsId,title,newsclass,ViewCount from RNews where 1=1");19 //如果它里面的字符串内容不等于空20 if(!string.IsNullOrEmpty(txtSTitle.Text.Trim()))21 {22 sb.Append(string.Format("and title like '%{0}%' ",txtSTitle.Text.Trim()));23 }24 if (ddlSNewsClass.SelectedIndex > 0)25 {26 sb.Append(string.Format("and NewsClass like '%{0}%' ",ddlSNewsClass.SelectedValue));27 }28 return sb.ToString();29 }30 31 protected void btnSelect_Click(object sender, EventArgs e)32 {33 BindRnews();34 }
好啦,这样子查询结果就出来啦,效果如上截图所示。
3.增加数据
1 <div> 2 <table> 3 <tr> 4 <td>标题:</td> 5 <td> 6 <asp:TextBox ID="txtITitle" runat="server"></asp:TextBox> 7 </td> 8 <td>内容:</td> 9 <td>10 <asp:TextBox ID="txtIText" runat="server"></asp:TextBox>11 </td>12 <td>分类:</td>13 <td>14 <asp:DropDownList ID="ddlINewsClass" runat="server">15 <asp:ListItem>--请选择--</asp:ListItem>16 <asp:ListItem>首页焦点</asp:ListItem>17 <asp:ListItem>业务信息</asp:ListItem>18 <asp:ListItem>学员感言</asp:ListItem>19 <asp:ListItem>常见问题</asp:ListItem>20 </asp:DropDownList>21 </td>22 <td>23 <asp:Button ID="btnAdd" runat="server" Text="添加" OnClick="btnAdd_Click" />24 </td>25 </tr>26 </table>27 </div>
.cs部分代码:
protected void btnAdd_Click(object sender, EventArgs e) { try { //1.获取到输入的标题,内容,选择的分类 string title = txtITitle.Text.Trim(); string text = txtIText.Text.Trim(); string rewsclass = ddlINewsClass.SelectedIndex > 0 ? ddlINewsClass.SelectedValue : ""; string strsql = string.Format("insert into RNews (Title,Text,CreatedTime,NewsClass) values ('{0}','{1}','{2}','{3}')", title, text, DateTime.Now.ToString(), rewsclass); //执行,判断有没有添加成功 if (SqlHelper.ExecteNonQueryText(strsql) > 0) { Response.Write("添加成功!"); } BindRnews(); } catch (Exception ex) { Response.Write("请联系管理员!"); } }
效果显示:
4.删除数据,通过Id删除数据
前端代码:
1 <div> 2 <table> 3 <tr> 4 <td>ID:</td> 5 <td> 6 <asp:TextBox ID="txtdDId" runat="server"></asp:TextBox> 7 </td> 8 <td> 9 <asp:Button ID="btnDelect" runat="server" Text="删除" OnClick="btnDelect_Click" />10 </td>11 </tr>12 </table>13 </div>
.cs代码:
1 protected void btnDelect_Click(object sender, EventArgs e) 2 { 3 try 4 { 5 if (!string.IsNullOrEmpty(txtdDId.Text.Trim())) 6 { 7 int id = Convert.ToInt32(txtdDId.Text.Trim()); 8 string strsql1 = string.Format("select NewsId from RNews where NewsId='{0}'", id); 9 if (SqlHelper.Exists(strsql1))10 {11 string strsql2 = string.Format("delete RNews where NewsId='{0}'", id);12 if (SqlHelper.ExecteNonQueryText(strsql2) > 0)13 {14 Response.Write("删除成功!");15 }16 BindRnews();17 }18 else19 {20 Response.Write("Id不存在!");21 }22 }23 else24 {25 Response.Write("请输入内容!");26 }27 }28 catch29 {30 Response.Write("请联系管理员!");31 }32 }
效果:
5.更新数据:
1 <div> 2 <table> 3 <tr> 4 <td>ID:</td> 5 <td> 6 <asp:TextBox ID="txtUId" runat="server"></asp:TextBox> 7 </td> 8 <td>标题:</td> 9 <td>10 <asp:TextBox ID="txtUTitle" runat="server"></asp:TextBox>11 </td>12 <td>13 <asp:Button ID="btnU" runat="server" Text="更新" OnClick="btnU_Click" />14 </td>15 </tr>16 </table>17 </div>
.cs
1 protected void btnU_Click(object sender, EventArgs e) 2 { 3 try 4 { 5 if (!string.IsNullOrEmpty(txtUId.Text.Trim())) 6 { 7 int Id = Convert.ToInt32(txtUId.Text.Trim()); 8 string strsql1 = string.Format("select NewsId from RNews where NewsId='{0}'",Id); 9 if (SqlHelper.Exists(strsql1))10 {11 string title = txtUTitle.Text.Trim();12 string strsql2 = string.Format("update RNews set Title= '{0}' where NewsId='{1}'", title, Id);13 if (SqlHelper.ExecteNonQueryText(strsql2) > 0)14 {15 Response.Write("更新成功!");16 }17 BindRnews();18 }19 else20 {21 Response.Write("ID不存在!");22 }23 }24 }25 catch26 {27 Response.Write("系统正在更新,请联系管理员!");28 }29 }
效果:
原标题:sqlHelper做增删改查
关键词:sql