using System;
using System.Data;
using System.Data.SqlClient;

namespace SysClassLibrary
{
/// <summary>
/// DataAccess 的摘要说明。
/// <description>数据处理基类,调用方式：DataAccess.DataSet((string)sqlstr);或者DataAccess.DataSet((string)sqlstr,ref DataSet ds); </description>
/// </summary>
public class DataAccess
{
#region 属性
protected static SqlConnection conn=new SqlConnection();
protected static SqlCommand comm=new SqlCommand();
#endregion
public DataAccess()
{
//init();
}
#region 内部函数 静态方法中不会执行DataAccess()构造函数

/// <summary>
/// 打开数据库连接
/// </summary>
private static void openConnection()
{
if (conn.State == ConnectionState.Closed)
{
//SysConfig.ConnectionString 为系统配置类中连接字符串，如："server=localhost;database=databasename;uid=sa;pwd=;"

conn.ConnectionString = SysConfig.ConnectionString ;
comm.Connection =conn;
try
{
conn.Open();
}
catch(Exception e)
{
throw new Exception(e.Message);
}
}
}
/// <summary>
/// 关闭当前数据库连接
/// </summary>
private static void closeConnection()
{
if(conn.State == ConnectionState.Open)
conn.Close();
conn.Dispose();
comm.Dispose();
}
#endregion
/// <summary>
/// 执行Sql查询语句
/// </summary>
/// <param name="sqlstr">传入的Sql语句</param>
public static void ExecuteSql(string sqlstr)
{
try
{
openConnection();
comm.CommandType =CommandType.Text ;
comm.CommandText =sqlstr;
comm.ExecuteNonQuery();
}
catch(Exception e)
{
throw new Exception(e.Message);