using MySql.Data.MySqlClient;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace TimedUpload
{
	class MysqlHelper
	{
		//数据库连接字符串(app.config来配置)，可以动态更改connectionString支持多数据库.
		private static string connectionString = ConfigurationManager.AppSettings["dbMysql"];
		 

		#region 公用方法
		/// <summary>
		/// 得到最大值
		/// </summary>
		/// <param name="FieldName"></param>
		/// <param name="TableName"></param>
		/// <returns></returns>
		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());
			}
		}
		/// <summary>
		/// 是否存在
		/// </summary>
		/// <param name="strSql"></param>
		/// <returns></returns>
		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;
			}
		}
		/// <summary>
		/// 是否存在（基于MySqlParameter）
		/// </summary>
		/// <param name="strSql"></param>
		/// <param name="cmdParms"></param>
		/// <returns></returns>
		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 (MySql.Data.MySqlClient.MySqlException e)
					{
						connection.Close();
						throw e;
					}
				}
			}
		}

		public static int ExecuteSqlByTime(string SQLString, int Times)
		{
			using (MySqlConnection connection = new MySqlConnection(connectionString))
			{
				using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
				{
					try
					{
						connection.Open();
						cmd.CommandTimeout = Times;
						int rows = cmd.ExecuteNonQuery();
						return rows;
					}
					catch (MySql.Data.MySqlClient.MySqlException e)
					{
						connection.Close();
						throw e;
					}
				}
			}
		}


		/// <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 int ExecuteSqlTran(List<String> SQLStringList)
		{
			using (MySqlConnection conn = new MySqlConnection(connectionString))
			{
				conn.Open();
				MySqlCommand cmd = new MySqlCommand();
				cmd.Connection = conn;
				MySqlTransaction tx = conn.BeginTransaction();
				cmd.Transaction = tx;
				try
				{
					int count = 0;
					for (int n = 0; n < SQLStringList.Count; n++)
					{
						string strsql = SQLStringList[n];
						if (strsql.Trim().Length > 1)
						{
							cmd.CommandText = strsql;
							count += cmd.ExecuteNonQuery();
						}
					}
					tx.Commit();
					return count;
				}
				catch
				{
					tx.Rollback();
					return 0;
				}
			}
		}
		/// <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);
				MySql.Data.MySqlClient.MySqlParameter myParameter = new MySql.Data.MySqlClient.MySqlParameter("@content", SqlDbType.NText);
				myParameter.Value = content;
				cmd.Parameters.Add(myParameter);
				try
				{
					connection.Open();
					int rows = cmd.ExecuteNonQuery();
					return rows;
				}
				catch (MySql.Data.MySqlClient.MySqlException e)
				{
					throw e;
				}
				finally
				{
					cmd.Dispose();
					connection.Close();
				}
			}
		}
		/// <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 object ExecuteSqlGet(string SQLString, string content)
		{
			using (MySqlConnection connection = new MySqlConnection(connectionString))
			{
				MySqlCommand cmd = new MySqlCommand(SQLString, connection);
				MySql.Data.MySqlClient.MySqlParameter myParameter = new MySql.Data.MySqlClient.MySqlParameter("@content", SqlDbType.NText);
				myParameter.Value = content;
				cmd.Parameters.Add(myParameter);
				try
				{
					connection.Open();
					object obj = cmd.ExecuteScalar();
					if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
					{
						return null;
					}
					else
					{
						return obj;
					}
				}
				catch (MySql.Data.MySqlClient.MySqlException e)
				{
					throw e;
				}
				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);
				MySql.Data.MySqlClient.MySqlParameter myParameter = new MySql.Data.MySqlClient.MySqlParameter("@fs", SqlDbType.Image);
				myParameter.Value = fs;
				cmd.Parameters.Add(myParameter);
				try
				{
					connection.Open();
					int rows = cmd.ExecuteNonQuery();
					return rows;
				}
				catch (MySql.Data.MySqlClient.MySqlException e)
				{
					throw e;
				}
				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 (MySql.Data.MySqlClient.MySqlException e)
					{
						connection.Close();
						throw e;
					}
				}
			}
		}
		public static object GetSingle(string SQLString, int Times)
		{
			using (MySqlConnection connection = new MySqlConnection(connectionString))
			{
				using (MySqlCommand cmd = new MySqlCommand(SQLString, connection))
				{
					try
					{
						connection.Open();
						cmd.CommandTimeout = Times;
						object obj = cmd.ExecuteScalar();
						if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
						{
							return null;
						}
						else
						{
							return obj;
						}
					}
					catch (MySql.Data.MySqlClient.MySqlException e)
					{
						connection.Close();
						throw e;
					}
				}
			}
		}
		/// <summary>
		/// 执行查询语句，返回MySqlDataReader ( 注意：调用该方法后，一定要对MySqlDataReader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 (MySql.Data.MySqlClient.MySqlException e)
			{
				throw e;
			}

		}
		/// <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 (MySql.Data.MySqlClient.MySqlException ex)
				{
					throw new Exception(ex.Message);
				}
				return ds;
			}
		}
		public static DataSet Query(string SQLString, int Times)
		{
			using (MySqlConnection connection = new MySqlConnection(connectionString))
			{
				DataSet ds = new DataSet();
				try
				{
					connection.Open();
					MySqlDataAdapter command = new MySqlDataAdapter(SQLString, connection);
					command.SelectCommand.CommandTimeout = Times;
					command.Fill(ds, "ds");
				}
				catch (MySql.Data.MySqlClient.MySqlException ex)
				{
					throw new Exception(ex.Message);
				}
				return ds;
			}
		}



		#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 (MySql.Data.MySqlClient.MySqlException e)
					{
						throw e;
					}
				}
			}
		}


		/// <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 ExecuteSqlTranWithIndentity(Hashtable SQLStringList)
		{
			using (MySqlConnection conn = new MySqlConnection(connectionString))
			{
				conn.Open();
				using (MySqlTransaction trans = conn.BeginTransaction())
				{
					MySqlCommand cmd = new MySqlCommand();
					try
					{
						int indentity = 0;
						//循环
						foreach (DictionaryEntry myDE in SQLStringList)
						{
							string cmdText = myDE.Key.ToString();
							MySqlParameter[] cmdParms = (MySqlParameter[])myDE.Value;
							foreach (MySqlParameter q in cmdParms)
							{
								if (q.Direction == ParameterDirection.InputOutput)
								{
									q.Value = indentity;
								}
							}
							PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
							int val = cmd.ExecuteNonQuery();
							foreach (MySqlParameter q in cmdParms)
							{
								if (q.Direction == ParameterDirection.Output)
								{
									indentity = Convert.ToInt32(q.Value);
								}
							}
							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 (MySql.Data.MySqlClient.MySqlException e)
					{
						throw e;
					}
				}
			}
		}

		/// <summary>
		/// 执行查询语句，返回MySqlDataReader ( 注意：调用该方法后，一定要对MySqlDataReader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 (MySql.Data.MySqlClient.MySqlException e)
			{
				throw e;
			}
			//            finally
			//            {
			//                cmd.Dispose();
			//                connection.Close();
			//            }

		}

		/// <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 (MySql.Data.MySqlClient.MySqlException 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 parameter in cmdParms)
				{
					if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) &&
						(parameter.Value == null))
					{
						parameter.Value = DBNull.Value;
					}
					cmd.Parameters.Add(parameter);
				}
			}
		}

		public static DataTable Fill(String sql)
		{
			DataTable dt = null;
			try
			{
				DataSet ds = Query(sql);
				if (ds.Tables.Count > 0)
				{
					dt = ds.Tables[0];
				}


			}
			catch (Exception ex)
			{
				dt = null;
				//throw;
			}
			return dt;
		}

		#endregion
	}
}