C#實現MySQL數據庫中的blob數據存儲

時間 2019-11-20

標籤 c# 實現 mysql 數據庫 blob 數據存儲欄目 C# 简体版

原文原文鏈接

 
 1 
 System.IO.MemoryStream ms =  
 new 
 System.IO.MemoryStream(); 
 
   
 2 
 private 
 void 
 button1_Click(object sender, EventArgs e) 
 
   
 3 
 { 
 
   
 4 
 //測試序列化與反序列化 
 
   
 5 
 int 
 [] arr = {  
 1 
 ,  
 2 
 ,  
 3 
 }; 
 
   
 6 
 BinaryFormatter bFormatter =  
 new 
 BinaryFormatter(); 
 
   
 7 
 bFormatter.Serialize(ms, arr); 
 
   
 8 
 byte 
 [] byteArr = ms.ToArray(); 
 
   
 9 
 MessageBox.Show(byteArr.Length.ToString()); 
 
 10 
 MySqlConnection conn =  
 new 
 MySqlConnection(Properties.Settings.Default.MySqlConnectString); 
 
 11 
 //string insertStr = "update mm set aa=4,arr=@blobData where aa=4;"; 
 
 12 
 string insertStr =  
 "insert into mm(arr) values(@blobData);" 
 ; 
 //須要主鍵設置自增 
 
 13 
 MySqlParameter par= 
 new 
 MySqlParameter( 
 "@blobData" 
 ,MySqlDbType.Blob); 
 
 14 
 par.Value=byteArr; 
 
 15 
 MySqlCommand cmd =  
 new 
 MySqlCommand(insertStr, conn); 
 
 16 
 cmd.Parameters.Add(par); 
 
 17 
 try 
 
 18 
 { 
 
 19 
 conn.Open(); 
 
 20 
 cmd.ExecuteNonQuery(); 
 
 21 
 ms.Close(); 
 
 22 
 ms.Dispose(); 
 
 23 
 } 
 
 24 
 catch 
 (Exception ep) 
 
 25 
 { 
 
 26 
 MessageBox.Show(ep.Message); 
 
 27 
 } 
 
 28 
 
 29 
 
 30 
 } 
 
 31 
 
 32 
 private 
 void 
 button2_Click(object sender, EventArgs e) 
 
 33 
 { 
 
 34 
 BinaryFormatter bFormatter =  
 new 
 BinaryFormatter(); 
 
 35 
 
 36 
 MySql.Data.MySqlClient.MySqlDataReader myData; 
 
 37 
 MySqlConnection  conn =  
 new 
 MySql.Data.MySqlClient.MySqlConnection(Properties.Settings.Default.MySqlConnectString); 
 
 38 
 string readStr =  
 "select arr from mm where id =6;" 
 ; 
 
 39 
 MySqlCommand cmd =  
 new 
 MySqlCommand(readStr, conn); 
 
 40 
 try 
 
 41 
 { 
 
 42 
 conn.Open(); 
 
 43 
 myData = cmd.ExecuteReader(); 
 
 44 
 if 
 (!myData.HasRows) 
 
 45 
 { 
 
 46 
 throw 
 new 
 Exception( 
 "沒有blob數據" 
 ); 
 
 47 
 } 
 
 48 
 myData.Read(); 
 
 49 
 byte 
 [] blob =  
 new 
 byte 
 [myData.GetBytes( 
 0 
 ,  
 0 
 ,  
 null 
 ,  
 0 
 ,  
 int 
 .MaxValue)]; 
 
 50 
 myData.GetBytes( 
 0 
 ,  
 0 
 , blob,  
 0 
 , blob.Length); 
 
 51 
 myData.Close(); 
 
 52 
 ms =  
 new 
 System.IO.MemoryStream(blob); 
 
 53 
 ms.Position =  
 0 
 ; 
 
 54 
 int 
 [] arr = ( 
 int 
 [])bFormatter.Deserialize(ms); 
 
 55 
 ms.Dispose(); 
 
 56 
 string arrStr =  
 null 
 ; 
 
 57 
 for 
 ( 
 int 
 i =  
 0 
 ; i < arr.GetLength( 
 0 
 ); i++) 
 
 58 
 { 
 
 59 
 arrStr += arr[i].ToString()+ 
 " " 
 ; 
 
 60 
 } 
 
 61 
 MessageBox.Show(arrStr); 
 
 62 
 } 
 
 63 
 catch 
 (Exception ep) 
 
 64 
 { 
 
 65 
 MessageBox.Show(ep.Message); 
 
 66 
 } 
 
 67 
 
 68 
 } 