using System;
using System.Collections;
using System.Data;
using MySql.Data.MySqlClient;

namespace FangYar.DBUtility
{
	/// <summary>
    /// 数据访问基础类(基于Oracle) Copyright (C) FangYar
	/// 可以用户可以修改满足自己项目的需要。
	/// </summary>
	public abstract class DbHelperOra
	{
        //数据库连接字符串(web.config来配置)，可以动态更改connectionString支持多数据库.		
        public static string connectionString = PubConstant.ConnectionString;     
		public DbHelperOra()
		{			
		}

        #region 公用方法
        
        public static int GetMaxID(string FieldName, string TableName)
        {
            string strsql = "select max(" + FieldName + ")+1 from " + TableName;
            object obj = GetSingle(strsql);
            if (obj == null)
            {
                return 1;
            }
            else
            {
                return int.Parse(obj.ToString());
            }
        }
        public static bool Exists(string strSql)
        {
            object obj = GetSingle(strSql);
            int cmdresult;
            if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
            {
                cmdresult = 0;
            }
            else
            {
                cmdresult = int.Parse(obj.ToString());
            }
            if (cmdresult == 0)
            {
                return false;
            }
            else
            {
                return true;
            }
        }

        public static bool Exists(string strSql, params MySqlParameter[] cmdParms)
        {
            object obj = GetSingle(strSql, cmdParms);
            int cmdresult;
            if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
            {
                cmdresult = 0;
            }
            else
            {
                cmdresult = int.Parse(obj.ToString());
            }
            if (cmdresult == 0)
            {
                return false;
            }
            else
            {
                return true;
            }
        }

       
        #endregion

		
		#region  执行简单SQL语句

		/// <summary>
		/// 执行SQL语句，返回影响的记录数
		/// </summary>
		/// <param name="SQLString">SQL语句</param>
		/// <returns>影响的记录数</returns>
		public static int ExecuteSql(string SQLString)
		{
			using (MySqlConnection connection = new MySqlConnection(connectionString))
			{				
				using (MySqlCommand cmd = new MySqlCommand(SQLString,connection))
				{
					try
					{		
						connection.Open();
						int rows=cmd.ExecuteNonQuery();
						return rows;
					}
					catch(Exception E)
					{					
						connection.Close();
						throw new Exception(E.Message);
					}
				}				
			}
		}
		
		/// <summary>
		/// 执行多条SQL语句，实现数据库事务。
		/// </summary>
		/// <param name="SQLStringList">多条SQL语句</param>		
		public static void ExecuteSqlTran(ArrayList SQLStringList)
		{
			using (MySqlConnection conn = new MySqlConnection(connectionString))
			{
				conn.Open();
				MySqlCommand cmd = new MySqlCommand();
				cmd.Connection=conn;				
				MySqlTransaction tx=conn.BeginTransaction();			
				cmd.Transaction=tx;				
				try
				{   		
					for(int n=0;n<SQLStringList.Count;n++)
					{
						string strsql=SQLStringList[n].ToString();
						if (strsql.Trim().Length>1)
						{
							cmd.CommandText=strsql;
							cmd.ExecuteNonQuery();
						}
					}										
					tx.Commit();					
				}
				catch(Exception E)
				{		
					tx.Rollback();
					throw new Exception(E.Message);
				}
			}
		}
		/// <summary>
		/// 执行带一个存储过程参数的的SQL语句。
		/// </summary>
		/// <param name="SQLString">SQL语句</param>
		/// <param name="content">参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加</param>
		/// <returns>影响的记录数</returns>
		public static int ExecuteSql(string SQLString,string content)
		{				
			using (MySqlConnection connection = new MySqlConnection(connectionString))
			{
				MySqlCommand cmd = new MySqlCommand(SQLString,connection);
                MySqlParameter myParameter = new MySqlParameter("@content", MySqlDbType.VarChar);
				myParameter.Value = content ;
				cmd.Parameters.Add(myParameter);
				try
				{
					connection.Open();
					int rows=cmd.ExecuteNonQuery();
					return rows;
				}
				catch(Exception E)
				{				
					throw new Exception(E.Message);
				}
				finally
				{
					cmd.Dispose();
					connection.Close();
				}	
			}
		}		
		/// <summary>
		/// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例)
		/// </summary>
		/// <param name="strSQL">SQL语句</param>
		/// <param name="fs">图像字节,数据库的字段类型为image的情况</param>
		/// <returns>影响的记录数</returns>
		public static int ExecuteSqlInsertImg(string strSQL,byte[] fs)
		{		
			using (MySqlConnection connection = new MySqlConnection(connectionString))
			{
				MySqlCommand cmd = new MySqlCommand(strSQL,connection);
                MySqlParameter myParameter = new MySqlParameter("@fs", MySqlDbType.LongBlob);
				myParameter.Value = fs ;
				cmd.Parameters.Add(myParameter);
				try
				{
					connection.Open();
					int rows=cmd.ExecuteNonQuery();
					return rows;
				}
				catch(Exception E)
				{				
					throw new Exception(E.Message);
				}
				finally
				{
					cmd.Dispose();
					connection.Close();
				}				
			}
		}
		
		/// <summary>
		/// 执行一条计算查询结果语句，返回查询结果（object）。
		/// </summary>
		/// <param name="SQLString">计算查询结果语句</param>
		/// <returns>查询结果（object）</returns>
		public static object GetSingle(string SQLString)
		{
			using (MySqlConnection connection = new MySqlConnection(connectionString))
			{
				using(MySqlCommand cmd = new MySqlCommand(SQLString,connection))
				{
					try
					{
						connection.Open();
						object obj = cmd.ExecuteScalar();
						if((Object.Equals(obj,null))||(Object.Equals(obj,System.DBNull.Value)))
						{					
							return null;
						}
						else
						{
							return obj;
						}				
					}
					catch(Exception e)
					{						
						connection.Close();
						throw new Exception(e.Message);
					}	
				}
			}
		}
		/// <summary>
        /// 执行查询语句，返回MySqlDataReader ( 注意：调用该方法后，一定要对SqlDataReader进行Close )
		/// </summary>
		/// <param name="strSQL">查询语句</param>
		/// <returns>MySqlDataReader</returns>
		public static MySqlDataReader ExecuteReader(string strSQL)
		{
			MySqlConnection connection = new MySqlConnection(connectionString);			
			MySqlCommand cmd = new MySqlCommand(strSQL,connection);				
			try
			{
				connection.Open();
                MySqlDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
				return myReader;
			}
			catch(Exception e)
			{								
				throw new Exception(e.Message);
			}			
			
		}		
		/// <summary>
		/// 执行查询语句，返回DataSet
		/// </summary>
		/// <param name="SQLString">查询语句</param>
		/// <returns>DataSet</returns>
		public static DataSet Query(string SQLString)
		{
			using (MySqlConnection connection = new MySqlConnection(connectionString))
			{
				DataSet ds = new DataSet();
				try
				{
					connection.Open();
					MySqlDataAdapter command = new MySqlDataAdapter(SQLString,connection);				
					command.Fill(ds,"ds");
				}
				catch(Exception ex)
				{				
					throw new Exception(ex.Message);
				}			
				return ds;
			}			
		}
        /// <summary>
        /// 执行查询语句，返回DataTable
        /// </summary>
        /// <param name="SQLString">查询语句</param>
        /// <returns>DataSet</returns>
        public static DataTable QueryTable(string SQLString)
        {
            using (MySqlConnection connection = new MySqlConnection(connectionString))
            {
                DataSet ds = new DataSet();
                try
                {
                    connection.Open();
                    MySqlDataAdapter command = new MySqlDataAdapter(SQLString, connection);
                    command.Fill(ds, "ds");
                }
                catch (Exception ex)
                {
                    throw new Exception(ex.Message);
                }
                return ds.Tables[0];
            }
        }

		#endregion

		#region 执行带参数的SQL语句

		/// <summary>
		/// 执行SQL语句，返回影响的记录数
		/// </summary>
		/// <param name="SQLString">SQL语句</param>
		/// <returns>影响的记录数</returns>
		public static int ExecuteSql(string SQLString,params MySqlParameter[] cmdParms)
		{
			using (MySqlConnection connection = new MySqlConnection(connectionString))
			{				
				using (MySqlCommand cmd = new MySqlCommand())
				{
					try
					{		
						PrepareCommand(cmd, connection, null,SQLString, cmdParms);
						int rows=cmd.ExecuteNonQuery();
						cmd.Parameters.Clear();
						return rows;
					}
					catch(Exception E)
					{				
						throw new Exception(E.Message);
					}
				}				
			}
		}
		
			
		/// <summary>
		/// 执行多条SQL语句，实现数据库事务。
		/// </summary>
		/// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的MySqlParameter[]）</param>
		public static void ExecuteSqlTran(Hashtable SQLStringList)
		{			
			using (MySqlConnection conn = new MySqlConnection(connectionString))
			{
				conn.Open();
				using (MySqlTransaction trans = conn.BeginTransaction()) 
				{
					MySqlCommand cmd = new MySqlCommand();
					try 
					{
						//循环
						foreach (DictionaryEntry myDE in SQLStringList)
						{	
							string 	cmdText=myDE.Key.ToString();
							MySqlParameter[] cmdParms=(MySqlParameter[])myDE.Value;
							PrepareCommand(cmd,conn,trans,cmdText, cmdParms);
							int val = cmd.ExecuteNonQuery();
							cmd.Parameters.Clear();

							trans.Commit();
						}					
					}
					catch 
					{
						trans.Rollback();
						throw;
					}
				}				
			}
		}
	
				
		/// <summary>
		/// 执行一条计算查询结果语句，返回查询结果（object）。
		/// </summary>
		/// <param name="SQLString">计算查询结果语句</param>
		/// <returns>查询结果（object）</returns>
		public static object GetSingle(string SQLString,params MySqlParameter[] cmdParms)
		{
			using (MySqlConnection connection = new MySqlConnection(connectionString))
			{
				using (MySqlCommand cmd = new MySqlCommand())
				{
					try
					{
						PrepareCommand(cmd, connection, null,SQLString, cmdParms);
						object obj = cmd.ExecuteScalar();
						cmd.Parameters.Clear();
						if((Object.Equals(obj,null))||(Object.Equals(obj,System.DBNull.Value)))
						{					
							return null;
						}
						else
						{
							return obj;
						}				
					}
					catch(Exception e)
					{				
						throw new Exception(e.Message);
					}					
				}
			}
		}
		
		/// <summary>
        /// 执行查询语句，返回MySqlDataReader ( 注意：调用该方法后，一定要对SqlDataReader进行Close )
		/// </summary>
		/// <param name="strSQL">查询语句</param>
		/// <returns>MySqlDataReader</returns>
		public static MySqlDataReader ExecuteReader(string SQLString,params MySqlParameter[] cmdParms)
		{		
			MySqlConnection connection = new MySqlConnection(connectionString);
			MySqlCommand cmd = new MySqlCommand();				
			try
			{
				PrepareCommand(cmd, connection, null,SQLString, cmdParms);
                MySqlDataReader myReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
				cmd.Parameters.Clear();
				return myReader;
			}
			catch(Exception e)
			{								
				throw new Exception(e.Message);
			}					
			
		}		
		
		/// <summary>
		/// 执行查询语句，返回DataSet
		/// </summary>
		/// <param name="SQLString">查询语句</param>
		/// <returns>DataSet</returns>
		public static DataSet Query(string SQLString,params MySqlParameter[] cmdParms)
		{
			using (MySqlConnection connection = new MySqlConnection(connectionString))
			{
				MySqlCommand cmd = new MySqlCommand();
				PrepareCommand(cmd, connection, null,SQLString, cmdParms);
				using( MySqlDataAdapter da = new MySqlDataAdapter(cmd) )
				{
					DataSet ds = new DataSet();	
					try
					{												
						da.Fill(ds,"ds");
						cmd.Parameters.Clear();
					}
					catch(Exception ex)
					{				
						throw new Exception(ex.Message);
					}			
					return ds;
				}				
			}			
		}


		private static void PrepareCommand(MySqlCommand cmd,MySqlConnection conn,MySqlTransaction trans, string cmdText, MySqlParameter[] cmdParms) 
		{
			if (conn.State != ConnectionState.Open)
				conn.Open();
			cmd.Connection = conn;
			cmd.CommandText = cmdText;
			if (trans != null)
				cmd.Transaction = trans;
			cmd.CommandType = CommandType.Text;//cmdType;
			if (cmdParms != null) 
			{
                foreach (MySqlParameter parm in cmdParms)
                {
                    if (parm.Value == null) parm.Value = System.DBNull.Value;
                    cmd.Parameters.Add(parm);
                }
			}
		}

		#endregion

		#region 存储过程操作

		/// <summary>
        /// 执行存储过程 返回SqlDataReader ( 注意：调用该方法后，一定要对SqlDataReader进行Close )
		/// </summary>
		/// <param name="storedProcName">存储过程名</param>
		/// <param name="parameters">存储过程参数</param>
		/// <returns>MySqlDataReader</returns>
		public static MySqlDataReader RunProcedure(string storedProcName, IDataParameter[] parameters )
		{
			MySqlConnection connection = new MySqlConnection(connectionString);
			MySqlDataReader returnReader;
			connection.Open();
			MySqlCommand command = BuildQueryCommand( connection,storedProcName, parameters );
			command.CommandType = CommandType.StoredProcedure;
            returnReader = command.ExecuteReader(CommandBehavior.CloseConnection);				
			return returnReader;			
		}
		
		
		/// <summary>
		/// 执行存储过程
		/// </summary>
		/// <param name="storedProcName">存储过程名</param>
		/// <param name="parameters">存储过程参数</param>
		/// <param name="tableName">DataSet结果中的表名</param>
		/// <returns>DataSet</returns>
		public static DataSet RunProcedure(string storedProcName, IDataParameter[] parameters, string tableName )
		{
			using (MySqlConnection connection = new MySqlConnection(connectionString))
			{
				DataSet dataSet = new DataSet();
				connection.Open();
				MySqlDataAdapter sqlDA = new MySqlDataAdapter();
				sqlDA.SelectCommand = BuildQueryCommand(connection, storedProcName, parameters );
				sqlDA.Fill( dataSet, tableName );
				connection.Close();
				return dataSet;
			}
		}

		
		/// <summary>
		/// 构建 MySqlCommand 对象(用来返回一个结果集，而不是一个整数值)
		/// </summary>
		/// <param name="connection">数据库连接</param>
		/// <param name="storedProcName">存储过程名</param>
		/// <param name="parameters">存储过程参数</param>
		/// <returns>MySqlCommand</returns>
		private static MySqlCommand BuildQueryCommand(MySqlConnection connection,string storedProcName, IDataParameter[] parameters)
		{			
			MySqlCommand command = new MySqlCommand( storedProcName, connection );
			command.CommandType = CommandType.StoredProcedure;
			foreach (MySqlParameter parameter in parameters)
			{
				command.Parameters.Add( parameter );
			}
			return command;			
		}
		
		/// <summary>
		/// 执行存储过程，返回影响的行数		
		/// </summary>
		/// <param name="storedProcName">存储过程名</param>
		/// <param name="parameters">存储过程参数</param>
		/// <param name="rowsAffected">影响的行数</param>
		/// <returns></returns>
		public static int RunProcedure(string storedProcName, IDataParameter[] parameters, out int rowsAffected )
		{
			using (MySqlConnection connection = new MySqlConnection(connectionString))
			{
				int result;
				connection.Open();
				MySqlCommand command = BuildIntCommand(connection,storedProcName, parameters );
				rowsAffected = command.ExecuteNonQuery();
				result = (int)command.Parameters["ReturnValue"].Value;
				//Connection.Close();
				return result;
			}
		}
		
		/// <summary>
		/// 创建 MySqlCommand 对象实例(用来返回一个整数值)	
		/// </summary>
		/// <param name="storedProcName">存储过程名</param>
		/// <param name="parameters">存储过程参数</param>
		/// <returns>MySqlCommand 对象实例</returns>
		private static MySqlCommand BuildIntCommand(MySqlConnection connection,string storedProcName, IDataParameter[] parameters)
		{
			MySqlCommand command = BuildQueryCommand(connection,storedProcName, parameters );
			command.Parameters.Add( new MySqlParameter ( "ReturnValue",
                MySqlDbType.Int32, 4, ParameterDirection.ReturnValue,
				false,0,0,string.Empty,DataRowVersion.Default,null ));
			return command;
		}
		#endregion	

	}
}