你这个问题很笼统啊。如果是数据库查询的话: select * from 表名 where 条件;如果是用VS2008里的新功能的话,看下linq语句 ;
using System; using System.Data; using System.Configuration; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls; using System.Data.OleDb; using System.Collections.Generic; using System.Windows.Forms;/// <summary> /// 对数据库的各种操作 /// </summary> public class DAO { string str = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("test.mdb"); OleDbConnection con; OleDbCommand cmd; public DAO() { con = new OleDbConnection(str); } //增删改的方法 public int InsertOrDelete(string sql) { try { con.Open(); cmd = new OleDbCommand(sql, con); int num = cmd.ExecuteNonQuery();
select * from 表名 where 条件;如果是用VS2008里的新功能的话,看下linq语句
;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.OleDb;
using System.Collections.Generic;
using System.Windows.Forms;/// <summary>
/// 对数据库的各种操作
/// </summary>
public class DAO
{
string str = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("test.mdb");
OleDbConnection con;
OleDbCommand cmd;
public DAO()
{
con = new OleDbConnection(str);
}
//增删改的方法
public int InsertOrDelete(string sql)
{
try
{
con.Open();
cmd = new OleDbCommand(sql, con);
int num = cmd.ExecuteNonQuery();
}catch(Exception ex)
{
MessageBox.Show("程序运行繁忙,请联系管理员");
}
finally
{
con.Close();
}
return num;
}
//查询的方法
public List<object> getShuJU(string sql)
{
con.Open();
cmd = new OleDbCommand(sql,con);
OleDbDataReader datareade = cmd.ExecuteReader();
while(datareade.Read())
{
}
}}
是用VS2008写的;
是我以前写组态软件时做的类库,支持SQL和Mysql;
功能很全了,你可以好好研究下