更方便快捷的外部操作数据库的方法(另类玩法)

using System; 
using System.Data; 
using System.Data.SqlClient; 
public class Helper 
{ 
public static void Main() 
{ 
//连接字符串 
string strcon = "server = .;database = blog;uid = sa;pwd = 1"; 
SqlHelper helper = new SqlHelper(strcon); 
//表employee中有neme(varchar(20)),age(int),sex(bit)三个字段; 
string sql = "select * from employee"; 
SqlDataReader reader = helper.Reader(sql,null); 
using (reader) 
{ 
while (reader.Read()) 
{ 
Console.WriteLine(reader["name"].ToString()); 
} 
} 
/*string sql = "insert into employee values(@name,@age,@sex)"; 
SqlParameter[] ps = new SqlParameter[] 
{ 
new SqlParameter("@name",SqlDbType.VarChar,20), 
new SqlParameter("@age",SqlDbType.Int), 
new SqlParameter("@sex",SqlDbType.Int) 
}; 
ps[0].Value = "张宇"; 
ps[1].Value = 40; 
ps[2].Value = 1; 
helper.ExecuteNonQuery(sql,ps);*/ 
} 
} 
public class SqlHelper 
{ 
private SqlConnection con = null; 
private SqlCommand cmd = null; 
public SqlHelper (string strcon) 
{ 
con = new SqlConnection(strcon); 
cmd = new SqlCommand(); 
cmd.Connection = con; 
} 
//执行初始化Command对象 
private void PreparedCommand(string sql,params SqlParameter[]param) 
{ 
cmd.CommandText = sql; 
//清空Parameteras中的对象 
cmd.Parameters.Clear(); 
if (param!=null) 
{ 
foreach (SqlParameter p in param) 
{ 
cmd.Parameters.Add(p); 
} 
} 
con.Open(); 
} 
/*执行非查询语句*/ 
//有参数 
public int ExecuteNonQuery(string sql,params SqlParameter[] param) 
{ 
PreparedCommand(sql,param); 
int i = cmd.ExecuteNonQuery(); 
Close(); 
return i; 
} 
//无参数 
public int ExecuteNonQuery(string sql) 
{ 
PreparedCommand(sql,null); 
int i = cmd.ExecuteNonQuery(); 
Close(); 
return i; 
} 
/*执行查询语句*/ 
//有参数 
public SqlDataReader Reader(string sql,params SqlParameter[] param) 
{ 
PreparedCommand(sql,param); 
return cmd.ExecuteReader(); 
} 
//无参数 
public SqlDataReader Reader(string sql) 
{ 
PreparedCommand(sql,null); 
return cmd.ExecuteReader(); 
} 
public void Open() 
{ 
con.Open(); 
} 
public void Close() 
{ 
cmd.Dispose(); 
con.Close(); 
} 
}