using System;
using System.Collections;
using System.Data;
using System.Data.OleDb;

namespace Eas.Client
{
	public class AccessHelper
	{
		/// <summary>
		/// 定义连接字符串字段connstring
		/// </summary>
		private static string connstring;

		/// <summary>
		/// 定义连接字符串属性ConnString
		/// </summary>
		public static string ConnString
		{
			get
			{
				return connstring;
			}
		}

		/// <summary>
		/// 定义连接对象字段conn
		/// </summary>
		private static OleDbConnection conn;

		/// <summary>
		/// 定义连接对象属性Conn
		/// </summary>
		public static OleDbConnection Conn
		{
			get
			{
				return conn;
			}
			set
			{
				conn = value;
			}
		}

		/// <summary>
		/// Database构造函数逻辑代码用来直接初始化连接字符串ConnString
		/// </summary>
		public AccessHelper()
		{
			connstring = System.Configuration.ConfigurationManager.ConnectionStrings["ConnectionString"].ToString();
			//string connStr = "Provider={0};Persist Security Info=False;Data Source={1};"; //Database Password={2};
			//string provider = System.Configuration.ConfigurationManager.AppSettings["Provider"].ToString();
			//string path = System.Windows.Forms.Application.StartupPath + System.Configuration.ConfigurationManager.AppSettings["Path"].ToString();
			//string password = System.Configuration.ConfigurationManager.AppSettings["Password"].ToString();
			//this.connstring = string.Format(connStr, provider,path);
		}

		/// <summary>
		/// 打开连接方法
		/// </summary>
		public static void Open()
		{
			if (Conn == null)
			{
				Conn = new OleDbConnection(ConnString);
			}
			if (Conn.State.Equals(ConnectionState.Closed))
			{
				Conn.ConnectionString = ConnString;
				Conn.Open();
			}
		}

		/// <summary>
		/// 打开连接方法
		/// </summary>
		public static void Open(string db)
		{
			string connStr = "Provider=Microsoft.ACE.OLEDB.12.0;Persist Security Info=False;Data Source={0}";
			connStr = string.Format(connStr, db);
			if (Conn == null)
			{
				Conn = new OleDbConnection(connStr);
			}
			if (Conn.State.Equals(ConnectionState.Closed))
			{
				Conn.ConnectionString = connStr;
				Conn.Open();
			}
		}

		/// <summary>
		/// 关闭数据库连接
		/// </summary>
		public static void Close()
		{
			if (Conn != null)
			{
				//this.connstring = "";
				Conn.Close();
				Conn.Dispose();
			}
		}

		/// <summary>
		/// 用于执行SQL语句的方法针对Update、Insert、Delete操作
		/// </summary>
		/// <param name="sqlString">SQL语句</param>
		/// <returns>针对Update、Insert、Delete操作返回影响的行数，其他就返回-1</returns>
		public static int ExecuteSql(string sqlString, string db)
		{
			int count = -1;

			try
			{
				Open(db);
				OleDbCommand cmd = new OleDbCommand(sqlString, Conn);
				count = cmd.ExecuteNonQuery();
			}
			catch (Exception ex)
			{
				count = -1;
			}
			finally
			{
				Close();
			}
			return count;
		}

		public static bool ExecuteSql(ArrayList sqlList, string db)
		{
			Open(db);
			OleDbTransaction tran = conn.BeginTransaction();
			try
			{
				for (int n = 0; n < sqlList.Count; n++)
				{
					OleDbCommand cmd = new OleDbCommand(sqlList[n].ToString());
					cmd.Connection = conn;
					cmd.Transaction = tran;
					cmd.ExecuteNonQuery();
				}
				tran.Commit();
				return true;
			}
			catch (Exception ex)
			{
				tran.Rollback();
				return false;
			}
			finally
			{
				conn.Close();
			}
		}

		/// <summary>
		/// 根据指定的select语句返回一个数据集DataSet
		/// </summary>
		/// <param name="sqlString">SQL语句</param>
		/// <returns>根据指定的select语句返回一个数据集DataSet</returns>
		public static DataSet Select(string sqlString, string db)
		{
			try
			{
				Open(db);
				OleDbDataAdapter sda = new OleDbDataAdapter(sqlString, conn);
				DataSet ds = new DataSet();
				sda.Fill(ds);

				//logger.Info(sqlString);
				return ds;
			}
			catch (Exception ex)
			{
				//logger.Info(ex.Message);

				//StreamWriter sw = new StreamWriter(@"c:\Log.txt");
				//sw.WriteLine(ex.Message);

				return null;
			}
			finally
			{
				Close();
			}
		}

		public static bool HasRow(DataSet ds)
		{
			return ds != null && ds.Tables.Count > 0 && ds.Tables[0].Rows.Count > 0;
		}

		public static bool HasRow(DataTable dt)
		{
			return dt != null && dt.Rows.Count > 0;
		}

		public static bool HasRow(DataRow dr)
		{
			return dr != null;
		}
	}
}