数据库的连接问题

1.在配置文件里面 <configuration>
<appSettings>
<add key="ConnectionString"

value="server=localhost;database=myWebDB;

UID=sa;pwd=123321"></add>
</appSettings> <connectionStrings/>

在页面后台里面

SqlConnection myConnection = new

SqlConnection(ConfigurationSettings.AppSettings

["ConnectionString"]);
myConnection.Open();

2.直接在一个类里面写，然后调用这个连接

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SqlClient;

namespace MyOfficeBBL
{
public class GetConnection
{
private static SqlConnection _connection;
/// <summary>
/// 获取数据库连接桥
/// </summary>
private static SqlConnection Connection
{
get
{
string connectionString = "Data Source=.;Initial Catalog=MyOffice;Integrated Security=True";
if (_connection == null)
{
_connection = new SqlConnection(connectionString);
_connection.Open();
}
if (_connection.State == ConnectionState.Closed)
{
_connection.Open();
}
if (_connection.State == ConnectionState.Broken)
{
_connection.Close();
_connection.Open();
}
return GetConnection._connection;
}

}
/// <summary>
/// 获取表数据
/// </summary>
/// <param name="sql"></param>
/// <returns></returns>
public static SqlDataReader GetDataRead(string sql)
{
SqlCommand command = new SqlCommand(sql, Connection);
SqlDataReader read = command.ExecuteReader();
return read;
}
public static int NoSelect(string sql)
{
SqlCommand command = new SqlCommand(sql, Connection);
int row = command.ExecuteNonQuery();
return row;
}
public static DataTable GetDataTable(string sql)
{
SqlCommand command = new SqlCommand(sql, Connection);
DataTable dt = new DataTable();
SqlDataAdapter sda = new SqlDataAdapter(command);
sda.Fill(dt);
return dt;
}

}
}