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

namespace 数据库
{
    class CommandSqlHelper
    {
        /// <summary>
        /// 数据库连接字符串
        /// </summary>
        private string ConnectionString
        {
            get
            {
                return ConfigurationManager.ConnectionStrings["connLocalhost"].ToString();
            }
        }

        /// <summary>
        /// 增,删,改数据库(sql语句, sql语句的参数)
        /// </summary>
        /// <returns></returns>
        private int DbOperation(string sql, SqlParameter[] parm)
        {
            //创建连接对象
            SqlConnection conn = new SqlConnection(ConnectionString);

            try
            {
                //创建命令对象
                SqlCommand command = new SqlCommand(sql, conn);

                //判断连接对象是否打开(未打开时打开) 
                //ConnectionState 枚举类型 => closed连接状态关闭 Broken连接状态中断
                if (conn.State == ConnectionState.Closed || conn.State == ConnectionState.Broken)
                {
                    conn.Open();
                }

                //给命令对象添加参数
                if (parm != null && parm.Length != 0)
                {
                    foreach (SqlParameter par in parm)
                    {
                        command.Parameters.Add(par);
                    }
                }

                //执行并返回受影响的行数
                return command.ExecuteNonQuery();
            }
            catch (Exception ex)
            {
                //抛出异常(ex.Message => 异常信息)
                throw new Exception(ex.Message);
            }
            finally
            {
                //关闭数据库
                conn.Close();
            }
        }

        /// <summary>
        /// 对外暴漏的测试方法
        /// </summary>
        public static void Show()
        {
            CommandSqlHelper command = new CommandSqlHelper();
            int result = command.DbOperation("update [User] [UserAge] = 100 where [UserAge] = 26", null);
            if (result > 0)
            {
                Console.WriteLine("操作成功{0}行改变", result);
            }
            else
            {
                Console.WriteLine("操作失败");
            }
        }
    }
}