请教一个C#+后台SQL的问题!

Question

新手求教，用C#调用SQL里面的一个表，显示出来。请问这个要怎么写？请帮忙写出完整代码

Answer 1

基本的数据库操作，select * from  tableA

Answer 2

首先在web.config 中配置一下：
<connectionStrings>  
    <add name="constr" connectionString="Data Source=192.168.18.12;Initial Catalog=SqlTest;User ID=sa;Password=1;Persist Security Info=True;" providerName="System.Data.SqlClient"/>  </connectionStrings>
然后再VS 中后台代码中建造一类类：DBHelp 类
using System;
using System.Data;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;namespace Test
{
    public class DBHelp 
    {
       private  string connectionstring ;        public string Connectionstring
        {
          get { return connectionstring; }
          set { connectionstring = value; }
        }
        private SqlTransaction sqltrans;        public SqlTransaction Sqltrans
        {
            get { return sqltrans; }
            set { sqltrans = value; }
        }      public   DBHelp()
        {
            Connectionstring = System.Configuration.ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        }        /// <summary>
        /// 根据语句来查询数据；
        /// </summary>
        /// <param name="sqlstr"></param>
        /// <returns></returns>
       public DataSet GetDataSet(string sqlstr)
       {
             
                 SqlConnection sqlconstring = new SqlConnection(Connectionstring);
                
               try
               {
                  
                   sqlconstring.Open();
                   SqlCommand com = GetCommand(sqlstr, sqlconstring);
                   SqlDataAdapter dt;
                   DataSet ds = new DataSet();
                   dt = GetAdaper(com);
                   dt.Fill(ds);
                   return ds;
                   Sqltrans.Commit();               }
               catch (Exception ex)
               {                   Sqltrans.Rollback();
                   return new DataSet();
                   throw;
               }
               finally
               {
                   sqlconstring.Close();
               }                }
 /// <summary>
        /// 根据语句来查询数据；
        /// </summary>
        /// <param name="sqlstr"></param>
        /// <returns></returns>
       public int Excutecount(string sqlstr)
       {           SqlConnection sqlconstring = new SqlConnection(Connectionstring);
    
           try
           {
               int count = 0;
               sqlconstring.Open();
               SqlCommand com = GetCommand(sqlstr, sqlconstring);             int.TryParse(com.ExecuteNonQuery().ToString(),out count);
               return count;
              // Sqltrans.Commit();           }
           catch (Exception ex)
           {               //Sqltrans.Rollback();
               return 0;
               throw;
           }
           finally
           {
               sqlconstring.Close();
           }
       }             public SqlDataAdapter GetAdaper(SqlCommand com)
       {
           
           return  new SqlDataAdapter(com);
       }
       public  SqlCommand GetCommand(string sqlstr, SqlConnection sqlconstring)
       {
           SqlCommand com = new SqlCommand(sqlstr);
           com.Connection = sqlconstring;
           return com;
       }        /// <summary>
        /// 根据查询语句获得行数
        /// </summary>
        /// <param name="sqlstr"></param>
        /// <returns></returns>
       internal int Getcount(string sqlstr)
       {
           SqlConnection sqlstrcon = new SqlConnection(Connectionstring);
           try
           {               sqlstrcon.Open();
               SqlCommand com = new SqlCommand(sqlstr, sqlstrcon);
               int temp=0;
               int.TryParse(com.ExecuteScalar().ToString(),out temp);
               int count = temp;
               return count;
               sqltrans.Commit();
           }catch(Exception  ex)
           {
               sqltrans.Rollback();
               return 0;
               throw;
           }finally
           {
               sqlstrcon.Close();
           }
       }
    }
}然后页面的cs 文件上：
 public void DataBind()
        {
            string sql="select * from dbo.Users";
            DataSet ds = db.GetDataSet(sql);
            this.RptList.DataSource = ds;//Gv是Repeater（数据源控件） 的id
            this.RptList.DataBind();
        }把 DataBind()在pageLoad 中调用一下；就可以了
页面的前台显示的写法是：
<asp:Repeater ID="RptList" runat="server" OnItemDataBound="RptList_ItemDataBound">
        <HeaderTemplate>
            <table width="500px">
                <tr>
                    <td>
                        id
                    </td>
                    <td>
                        姓名
                    </td>
                    <td>
                        性别
                    </td>
                </tr>
        </HeaderTemplate>
        <ItemTemplate>
            <tr id="trrow" runat="server">
                <td>
                    <a href="#" onmouseout="Hide();"  onmouseover="showHelper('#H01', '<%#Eval("Name")%>', '<%#Eval("Name")%>,<%#Eval("Name")%>',30)" onmouseout="$('#_Popup_help').remove()">
                        <%#Eval("id")%></a>
                </td>
                <td>
                   <a href="#" onmouseout="Hide();" onmousemove="Show('<%#Eval("Name")%>,<%#Eval("Name")%>');"><%#Eval("Name")%></a>
                </td>
                <td>
                
                    <%#Eval("Sex").ToString()=="True"?"男":"女"%>
                </td>
            </tr>
        </ItemTemplate>
        <FooterTemplate>
            </table>
        </FooterTemplate>
    </asp:Repeater>

Answer 3

http://download.csdn.net/detail/xujinli88/3862074这是我平常练习的小的东西 你可以看一下 数据库的配置文件你要改一下 还有自己根据代码建一下数据库 功能都是可以实现的

Answer 4

用DATAGRIDVIEW控件，数据源设置为表查询返回的DataTable或者实体。
SQL语句 select * from TableName

Answer 5

我给你看一个视频吧~~包你什么都学会了百度“易学之道MrYoung”这个老师的课，讲的很通俗易懂。对你有帮助的话，请给分。