C#実装操作MySqlデータ層クラスMysqlHelperインスタンス

この例では、C#実装動作MySqlデータ層クラスMysqlHelperについて説明する.皆さんの参考にしてください.具体的には以下の通りです.

using System;
using System.Data;
using System.Configuration;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;
using MySql.Data;
using MySql.Data.MySqlClient;
namespace VideoWorks.ITmanage.DAL
{
 public abstract class MySqlHelper
 {
  //        
  public static string Conn = "Database='device_manage';Data Source='localhost';User Id='root';Password='123456';charset='utf8';pooling=true;Allow Zero Datetime=True";
  /// 

  ///                  sql  （      ）
  /// 
  ///           
  ///     (    ,   ,   )
  ///         sql    
  ///            
  ///           
  public static int ExecuteNonQuery(string connectionString, CommandType cmdType, string cmdText, params MySqlParameter[] commandParameters)
  {
   MySqlCommand cmd = new MySqlCommand();
   using (MySqlConnection conn = new MySqlConnection(connectionString))
   {
    PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
    int val = cmd.ExecuteNonQuery();
    cmd.Parameters.Clear();
    return val;
   }
  }
  /// 

  ///              sql  （      ）
  /// 
  ///           
  ///     (    ,   ,   )
  ///         sql    
  ///            
  ///           
  public static int ExecuteNonQuery(MySqlConnection connection, CommandType cmdType, string cmdText, params MySqlParameter[] commandParameters)
  {
   MySqlCommand cmd = new MySqlCommand();
   PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
   int val = cmd.ExecuteNonQuery();
   cmd.Parameters.Clear();
   return val;
  }
  /// 

  ///     SQL      sql  （      ）
  /// 
  /// 
  ///  :
  /// int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new MySqlParameter("@prodid", 24));
  /// 
  ///        
  ///     (    ,   ,   )
  ///         sql    
  ///            
  ///           
  public static int ExecuteNonQuery(MySqlTransaction trans, CommandType cmdType, string cmdText, params MySqlParameter[] commandParameters)
  {
   MySqlCommand cmd = new MySqlCommand();
   PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters);
   int val = cmd.ExecuteNonQuery();
   cmd.Parameters.Clear();
   return val;
  }
  /// 

  ///                    sql  
  /// 
  /// 
  ///   :
  /// MySqlDataReader r = ExecuteReader(connString, CommandType.StoredProcedure, "PublishOrders", new MySqlParameter("@prodid", 24));
  /// 
  ///           
  ///     (    ,   ,   )
  ///         sql    
  ///            
  ///         
  public static MySqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params MySqlParameter[] commandParameters)
  {
   //    MySqlCommand  
   MySqlCommand cmd = new MySqlCommand();
   //    MySqlConnection  
   MySqlConnection conn = new MySqlConnection(connectionString);
   //        try/catch    sql    /    ，                     ，         ，
   //  commandBehaviour.CloseConnection      
   try
   {
    //   PrepareCommand   ，  MySqlCommand       
    PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
    //   MySqlCommand   ExecuteReader   
    MySqlDataReader reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
    //    
    cmd.Parameters.Clear();
    return reader;
   }
   catch
   {
    //    ，    
    conn.Close();
    throw;
   }
  }
  /// 

  ///   DataSet
  /// 
  ///           
  ///     (    ,   ,   )
  ///         sql    
  ///            
  /// 
  public static DataSet GetDataSet(string connectionString, CommandType cmdType, string cmdText, params MySqlParameter[] commandParameters)
  {
   //    MySqlCommand  
   MySqlCommand cmd = new MySqlCommand();
   //    MySqlConnection  
   MySqlConnection conn = new MySqlConnection(connectionString);
   //        try/catch    sql    /    ，
   //                     ，         ，
   try
   {
    //   PrepareCommand   ，  MySqlCommand       
    PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
    //   MySqlCommand   ExecuteReader   
    MySqlDataAdapter adapter = new MySqlDataAdapter();
    adapter.SelectCommand = cmd;
    DataSet ds = new DataSet();
    adapter.Fill(ds);
    //    
    cmd.Parameters.Clear();
    conn.Close();
    return ds;
   }
   catch (Exception e)
   {
    throw e;
   }
  }
  /// 

  ///                               
  /// 
  /// 
  ///  :
  /// Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new MySqlParameter("@prodid", 24));
  /// 
  ///          
  ///     (    ,   ,   )
  ///         sql    
  ///            
  ///   Convert.To{Type}          
  public static object ExecuteScalar(string connectionString, CommandType cmdType, string cmdText, params MySqlParameter[] commandParameters)
  {
   MySqlCommand cmd = new MySqlCommand();
   using (MySqlConnection connection = new MySqlConnection(connectionString))
   {
    PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
    object val = cmd.ExecuteScalar();
    cmd.Parameters.Clear();
    return val;
   }
  }
  /// 

  ///                            
  /// 
  /// 
  ///   :
  /// Object obj = ExecuteScalar(connString, CommandType.StoredProcedure, "PublishOrders", new MySqlParameter("@prodid", 24));
  /// 
  ///           
  ///     (    ,   ,   )
  ///         sql    
  ///            
  ///   Convert.To{Type}          
  public static object ExecuteScalar(MySqlConnection connection, CommandType cmdType, string cmdText, params MySqlParameter[] commandParameters)
  {
   MySqlCommand cmd = new MySqlCommand();
   PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
   object val = cmd.ExecuteScalar();
   cmd.Parameters.Clear();
   return val;
  }
  /// 

  ///         
  /// 
  /// sql  
  /// OleDb  
  /// OleDb  
  ///                
  ///     ,  :Select * from Products
  ///        
  private static void PrepareCommand(MySqlCommand cmd, MySqlConnection conn, MySqlTransaction trans, CommandType cmdType, 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 = cmdType;
   if (cmdParms != null)
   {
    foreach (MySqlParameter parm in cmdParms)
     cmd.Parameters.Add(parm);
   }
  }
 }
}

本稿で述べたことが皆さんのC#プログラム設計に役立つことを願っています.