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

/// <summary>
///DBacess 的摘要说明
/// </summary>
namespace basic
{

    public class DBacess
    {
        /// <summary>
        /// 创建活动SqlConnection
        /// </summary>
        /// <returns>SqlConnection</returns>
        /// 
        public static SqlConnection con;
        private static SqlConnection connection()
        {
            SqlConnection conn = new SqlConnection(System.Configuration.ConfigurationManager.AppSettings["ConnectionString"].ToString());
            con = conn;
            return conn;
        }
        /// <summary>
        /// 打开连接数据库
        /// </summary>
        /// <param name="conn">SqlConnection对象</param>
        private void OpenConnection(SqlConnection conn)
        {
            if (conn != null && conn.State == ConnectionState.Closed)
                conn.Open();
        }

        /// <summary>
        /// 关闭数据库
        /// </summary>
        /// <param name="conn">SqlConnection对象</param>
        private void CloseConnection(SqlConnection conn)
        {
            if (conn != null && conn.State == ConnectionState.Open)
                conn.Close();
        }
        /// <summary>
        /// 更新数据库
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="parameters"></param>
        /// <param name="type"></param>
        /// <returns></returns>
        public bool Update(string sql, SqlParameter[] parameters, CommandType type)
        {
            SqlConnection conn = connection();
            bool result = false;
            try
            {
                using (conn)
                {
                    SqlCommand cmd = new SqlCommand(sql, conn);
                    if (parameters != null)
                    {
                        foreach (SqlParameter parameter in parameters)
                        {
                            if (parameters != null && parameter.ParameterName != "")
                            {
                                cmd.Parameters.Add(parameter);
                            }
                        }
                    }
                    cmd.CommandType = type;
                    cmd.Connection.Open();
                    int flag = cmd.ExecuteNonQuery();
                    if (flag > 0)
                        result = true;
                }
            }
            finally
            {
                CloseConnection(conn);
            }
            return result;

        }
        /// <summary>
        /// 根据条件查询数据
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="parameters"></param>
        /// <returns>DataTable</returns>
        public DataTable SelectReturnDataTable(string sql, SqlParameter[] parameters)
        {
            SqlConnection conn = connection();
            DataTable dt = new DataTable();
            try
            {
                using (conn)
                {
                    SqlCommand cmd = new SqlCommand(sql, conn);
                    if (parameters != null)
                    {
                        foreach (SqlParameter parameter in parameters)
                        {
                            if (parameter != null && parameter.ParameterName != "")
                            {
                                cmd.Parameters.Add(parameter);
                            }
                        }
                    }
                    conn.Open();
                    SqlDataAdapter sda = new SqlDataAdapter(cmd);

                    sda.Fill(dt);
                }
            }
            //catch (Exception e)
            //{

            //}
            finally
            {
                CloseConnection(conn);
            }
            return dt;
        }
        /// <summary>
        /// 根据条件查询数据
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="parameters"></param>
        /// <returns>DataSet</returns>
        public DataSet SelectReturnDataSet(string sql, SqlParameter[] parameters)
        {
            SqlConnection conn = connection();
            DataSet ds = new DataSet();
            try
            {
                using (conn)
                {
                    SqlCommand cmd = new SqlCommand(sql, conn);
                    if (parameters != null)
                    {
                        foreach (SqlParameter parameter in parameters)
                        {
                            if (parameter != null && parameter.ParameterName != "")
                            {
                                cmd.Parameters.Add(parameter);
                            }
                        }
                    }
                    conn.Open();
                    SqlDataAdapter sda = new SqlDataAdapter(cmd);

                    sda.Fill(ds);
                }
            }
            //catch (Exception e)
            //{

            //}
            finally
            {
                CloseConnection(conn);
            }
            return ds;
        }
    }
}