.net选择数据库表\列导出数据

遐迩之余.做了一下数据导出.因为数据库有许多数据木必要导出来.所以就做了,选择表,动态根据表选择对应的列.然后导出.有些地方需要改进...只是练下手.有时间再改吧

下面直接贴码

首先页面

 <form id="form1" runat="server">
    <div>//这里声明一下.其实可以做成无刷新的,使用jquery+ajax. 有空再改吧.
        选择表名:<asp:DropDownList runat="server" ID="ddlTable" AutoPostBack="True" OnSelectedIndexChanged="ddlTable_SelectedIndexChanged">
        </asp:DropDownList>
    </div>
    <div>
        <asp:GridView ID="Gridview1" runat="server" AutoGenerateColumns="False">
            <Columns>
                <asp:TemplateField HeaderText="勾选列">
                    <ItemTemplate>
                        <asp:CheckBox ID="CheckBox1" runat="server" Text="<%#Container.DataItem%>" />
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:TemplateField HeaderText="列名">
                    <ItemTemplate>
                        <%#Container.DataItem%>
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>
    </div>
    <asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
    </form>

后台cs

  protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {   //这里sqlhelper是我的数据库操作类.就不贴出了.ExecuteReader(sql语句是查询数据库里的所有表.这个在我博客的另一篇随笔有详细介绍)
                SqlDataReader dr = SqlHelper.ExecuteReader("SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE = 'BASE TABLE'");
                while (dr.Read())
                {
                    this.ddlTable.Items.Add(new ListItem() { Text = dr.GetString(0), Value = dr.GetString(0) });
                }
                this.ddlTable.DataBind();
            }
        }

　　　　　//根据选择的表.去找出相应的列.这里有点二了.竟然用存储过程..涐晕了.以后再改
        protected void ddlTable_SelectedIndexChanged(object sender, EventArgs e)
        {
            string tname = this.ddlTable.SelectedValue;
            SqlParameter[] parms = new SqlParameter[] { 
                new SqlParameter("@tablename", SqlDbType.NVarChar) { Value =tname }
            };

            using (SqlConnection conn = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["DbConnString"].ConnectionString))
            {

                IList<string> list = new List<string>();
                SqlCommand cmd = conn.CreateCommand();
                cmd.CommandText = "test";
                cmd.CommandType = CommandType.StoredProcedure;
                cmd.Parameters.AddRange(parms);
                conn.Open();
                using (IDataReader reader = cmd.ExecuteReader())
                {
                    while (reader.Read())
                    {
                        list.Add(reader.GetString(0));
                    }
                }
                conn.Close();
                this.Gridview1.DataSource = list;
                this.Gridview1.DataBind();
            }
        }

　　　　　　//这里就是导出txt
        protected void Button1_Click(object sender, EventArgs e)
        {
            string sb="";
            foreach (GridViewRow item in Gridview1.Rows)
            {
                CheckBox ck = item.FindControl("CheckBox1") as CheckBox;
                if (ck.Checked)
                {
                    sb += ck.Text + ',';
                }
            }
            if (!string.IsNullOrEmpty(sb))
            {
                string a = sb.Substring(0,sb.Length- 1);
                string sql = "select " + a + " from " + this.ddlTable.SelectedValue;
                DataSet ds = SqlHelper.ExecuteDataset(sql);
                DataTable dt = ds.Tables[0];
                string path=Server.MapPath("/")+this.ddlTable.SelectedValue+".txt";
                if (!File.Exists(path))
                {
                    CreateToFile(this.ddlTable.SelectedValue);
                }
                for (int i = 0; i < dt.Rows.Count; i++)
                {
                    for (int j = 0; j< dt.Columns.Count; j++)
                    {
                        File.AppendAllText(path, dt.Rows[i][j].ToString()+"$DD$", Encoding.UTF8);
                    }
                    File.AppendAllText(path,"$RR$", Encoding.UTF8);
                }
            }
           
        }
        public void CreateToFile(string name)
        {
            string FileName = Server.MapPath("/")+name+".txt";
            using (StreamWriter SW = new StreamWriter(FileName, true, Encoding.UTF8))
            {
                SW.AutoFlush = true;
                SW.Write(string.Empty);
                SW.Close();
            }
        }

这里就把存储过程贴出来,其实可以不用存储过程的...希望大家要是使用的时候可以直接用sql

USE [FBBlock]
GO
/****** Object:  StoredProcedure [dbo].[test]    Script Date: 12/05/2011 09:49:42 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER procedure [dbo].[test]
 @tablename nvarchar(50)
 as
 select name from syscolumns where id=object_id(''+@tablename+'')