C#做C/S程序,数据库连接怎么写,请帮忙! 初次接触 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 在server端写数据库连接程序,然后client端调用server端发送读取或修改数据库的函数,以此来达到client端对数据库进行操作。server在这之中起到一个数据转发的作用。 建议直接拖拽“服务器”视图中的数据库,自动代码以后,慢慢看吧!或者在MSDN中或者网上搜索ADO.NET,到处都有很详细的资料的熟悉这样几个对象就可以了,SQLConnection(或者OleDBConnection)、SQLCommand、Dataset等基本就可以写常用的操作了MSDN里卖弄有实例代码 给你一个事例,不过用的是datareader string sql="select * from yh"; //第一步:打开连接 SqlConnection conn=new SqlConnection(DB.ConnectString//连接字符串); conn.Open(); //第二步:执行命令 SqlCommand cmd=new SqlCommand(); cmd.CommandText=sql; cmd.Connection=conn; Datareader dr=cmd.ExecuteReader();//只能这样创建 if(dr.Read())读一行 { this.textBox2.Text=dr["yhm"//字段索引].ToString();//读取yhm字段 } 楼上的你打开太早,效率比较慢先写配置文件,这样代码看起舒服些<?xml version="1.0" encoding="utf-8" ?><configuration> <appSettings> <add key = "strKey" value = "server = (local); uid = sa; database = name"/> </appSettings></configuration>然后是连接数据库的代码SqlConnection conn = new SqlConnection(ConfigurationSettings.AppSettings["strKey"].ToString()); SqlDataAdapter da = new SqlDataAdapter("select * from name", conn); DataSet ds = new DataSet(); try { conn.Open(); da.Fill(ds, "name"); catch(Exception ex) { conn.Close(); MessageBox.Show(ex.Message); } finally { conn.Close(); } dbgBooksDt.DataSource = ds.Tables["name"]; 保存的... OleDbConnection objCon = new OleDbConnection(strconnect); string strQuery = "INSERT INTO DiMing VALUES('" + name + "', '" + data + "','')"; OleDbCommand objCmd = new OleDbCommand(strQuery, objCon); try { objCmd.Connection.Open(); objCmd.ExecuteNonQuery(); } catch (System.Exception Exp) { string temp = Exp.ToString(); } objCmd.Connection.Close();读取得...string reStr = string.Empty; try { string strconnect = Mhxy.PublicClass.Data.ConnectionString.ConString(); OleDbConnection myConnection = new OleDbConnection(strconnect); string sqlstr = "SELECT BZData FROM BuZhuoSub WHERE reg='" + reg + "' AND server='" + server + "' AND name='" + name + "' AND address='" + address + "' AND CWName='" + CWData + "'"; System.Data.OleDb.OleDbCommand objCmd = new OleDbCommand(sqlstr, myConnection); objCmd.Connection.Open(); System.Data.OleDb.OleDbDataReader myReader = objCmd.ExecuteReader(); myReader.Read(); reStr = myReader[0].ToString(); myReader.Close(); objCmd.Connection.Close(); } catch (System.Exception Exp) { object temp = Exp; }很乱,慢慢看吧 利用Remoting,远程调用服务器。 配置文件在分层架构的DLL中无法读取! 有谁有导入过加密码的Excel?跪求帮助,谢谢! ConfigurationSettings.AppSettings该怎样使用? 邮件发送问题,SendAsync 异步调用无效?急!在线等待。 当表单中出现中文的时候录入数据库就变成乱码,不知道如何解决 c#数组追加问题? VS.net2003中,回车键,退回键都失效了。为什没会这样啊? 请教各位SharpZipLib控件怎样支持中文名称 一个小问题求指点?事件??? 在.net下怎么过滤敏感字 一道面试题分享 listBox的右击事件 水晶报表怎么打印照片!
基本就可以写常用的操作了MSDN里卖弄有实例代码
string sql="select * from yh";
//第一步:打开连接
SqlConnection conn=new SqlConnection(DB.ConnectString//连接字符串);
conn.Open();
//第二步:执行命令
SqlCommand cmd=new SqlCommand();
cmd.CommandText=sql;
cmd.Connection=conn;
Datareader dr=cmd.ExecuteReader();//只能这样创建
if(dr.Read())读一行
{
this.textBox2.Text=dr["yhm"//字段索引].ToString();//读取yhm字段
}
先写配置文件,这样代码看起舒服些
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<appSettings>
<add key = "strKey" value = "server = (local); uid = sa; database = name"/>
</appSettings>
</configuration>然后是连接数据库的代码
SqlConnection conn = new SqlConnection(ConfigurationSettings.AppSettings["strKey"].ToString());
SqlDataAdapter da = new SqlDataAdapter("select * from name", conn);
DataSet ds = new DataSet();
try
{
conn.Open();
da.Fill(ds, "name");
catch(Exception ex)
{
conn.Close();
MessageBox.Show(ex.Message);
}
finally
{
conn.Close();
} dbgBooksDt.DataSource = ds.Tables["name"];
OleDbConnection objCon = new OleDbConnection(strconnect);
string strQuery = "INSERT INTO DiMing VALUES('" + name + "', '" + data + "','')";
OleDbCommand objCmd = new OleDbCommand(strQuery, objCon);
try
{
objCmd.Connection.Open();
objCmd.ExecuteNonQuery();
}
catch (System.Exception Exp)
{
string temp = Exp.ToString();
}
objCmd.Connection.Close();
读取得...
string reStr = string.Empty;
try
{
string strconnect = Mhxy.PublicClass.Data.ConnectionString.ConString();
OleDbConnection myConnection = new OleDbConnection(strconnect);
string sqlstr = "SELECT BZData FROM BuZhuoSub WHERE reg='" + reg + "' AND server='" + server +
"' AND name='" + name + "' AND address='" + address + "' AND CWName='" + CWData + "'";
System.Data.OleDb.OleDbCommand objCmd = new OleDbCommand(sqlstr, myConnection);
objCmd.Connection.Open();
System.Data.OleDb.OleDbDataReader myReader = objCmd.ExecuteReader();
myReader.Read();
reStr = myReader[0].ToString();
myReader.Close();
objCmd.Connection.Close();
}
catch (System.Exception Exp)
{
object temp = Exp;
}
很乱,慢慢看吧