using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
namespace Web.Services
{
public class DBHelperNew
{
private static SqlConnection connection;
//public static SqlConnection Connection
//{
// get
// {
// //类似单例模式
// if (connection == null) connection = new SqlConnection
// ("server=.;database=Practice;uid=sa;pwd=sa");
// return connection;
// }
//}
public static SqlConnection Connection
{
get
{
if (connection == null) connection = new SqlConnection(
ConfigurationManager.ConnectionStrings["con"].ConnectionString
);
if (connection.State == ConnectionState.Broken)
{
connection.Close();
}
connection.Open();
return connection;
}
}
public static SqlCommand Command
{
get { return Connection.CreateCommand(); }
}
public static bool Update(string sql)
{
var cmd = Command;
cmd.CommandText = sql;
try
{
var result = cmd.ExecuteNonQuery();
cmd.Connection.Close();
return result > 0;
}
catch (Exception ex)
{
cmd.Connection.Close();
throw;
}
}
public static object SelectForScalar(string sql)
{
var cmd = Command;
cmd.CommandText = sql;
try
{
var result = cmd.ExecuteScalar();
cmd.Connection.Close();
return result;
}
catch (Exception e)
{
cmd.Connection.Close();
throw;
}
}
public static SqlDataReader SelectForReader(string sql)
{
var cmd = Command;
cmd.CommandText = sql;
try
{
return cmd.ExecuteReader(CommandBehavior.CloseConnection);
}
catch (Exception e)
{
cmd.Connection.Close();
throw;
}
}
}
}