將圖像從UIImagePicker保存到Sqlite數據庫

Question

所以我正在做的是用戶從相機膠捲中選擇一個圖像，我設置了一個imageView與該圖像。到現在爲止還挺好。現在我需要將此圖像保存到我的數據庫中。因此，當下次加載視圖時，我再次選擇了該圖像。問題是我的圖像視圖沒有與圖像設置。可能是因爲它沒有正確保存到我的數據庫。從我讀NSData是最好使用和它正在使用，但沒有成功。有人可以幫助解決我的問題嗎？

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info{ 

    [self dismissViewControllerAnimated:YES completion:nil]; 
    fsImageView.image = [info objectForKey:UIImagePickerControllerOriginalImage]; 
    fsUIImage = [info objectForKey:UIImagePickerControllerOriginalImage]; 
    imgData = UIImagePNGRepresentation(fsUIImage); 
    [self saveImageToDatabase]; 

} 

------我在這裏我的圖像保存到數據庫-------

-(void)saveImageToDatabase{ 

    [self openDB]; 

    sqlite3_stmt *newstatement; 

    int originalTotalCount = sqlite3_total_changes(db); 

    NSString *sql = [NSString stringWithFormat:@"UPDATE Annotation SET image = '%@' WHERE title ='%@'", imgData, fsTitleName]; 
    if (sqlite3_prepare_v2(db, [sql UTF8String], -1, &newstatement, nil) != SQLITE_OK) { 
     NSLog(@"%s: prepare failed: %s", __FUNCTION__, sqlite3_errmsg(db)); 
    } else { 
     if (sqlite3_step(newstatement) != SQLITE_DONE) { 
      NSLog(@"%s: step failed: %s", __FUNCTION__, sqlite3_errmsg(db)); 
     } else { 
      int rowsUpdated = sqlite3_total_changes(db) - originalTotalCount; 

      NSString *message; 

      if (rowsUpdated == 1) 
       message = @"Updated one row"; 
      else if (rowsUpdated == 0) 
       message = @"No rows updated"; 
      else 
       message = [NSString stringWithFormat:@"Updated %d rows", rowsUpdated]; 

      NSLog(@"%@", message); 

      sqlite3_step(newstatement); 
     } 

     sqlite3_finalize(newstatement); 
    } 
    sqlite3_close(db); 

} 

------在這裏，我拉我的形象從DB- ------被調用時viewLoads ..

-(void)setImage{ 

    [self openDB]; 

    NSString *sql = [NSString stringWithFormat:@"SELECT image FROM Annotation WHERE title = '%@'",fsTitleName]; 

    sqlite3_stmt *statement; 

    if(sqlite3_prepare_v2(db, [sql UTF8String], -1, &statement, nil) == SQLITE_OK){ 

     int rc; 
     if ((rc = sqlite3_step(statement)) == SQLITE_ROW) { 
      char *field1 = (char *) sqlite3_column_text(statement, 0); 
      NSString *field1Str = [[NSString alloc]initWithUTF8String:field1]; 
      imgData = [field1Str dataUsingEncoding:NSUTF8StringEncoding]; 
      [fsImageView setImage:[UIImage imageWithData: imgData]]; 

     } else if (rc != SQLITE_DONE) { 
      NSLog(@"%s: sqlite3_step failed: %s", __FUNCTION__, sqlite3_errmsg(db)); 
     } 
    } else { 
     NSLog(@"%s: sqlite3_prepare_v2 failed: %s", __FUNCTION__, sqlite3_errmsg(db)); 
    } 

    sqlite3_finalize(statement); 
    sqlite3_close(db); 


} 

Answer 1

在你的情況你獲得成功的圖像，並將其轉換爲NSData的存儲在sqlite的，唯一的問題你面對被存儲的NSData到sqlite的。

將NSData保存到sqlite數據庫中需要將它保存爲sqlite中的字節，因此要麼以字節存儲NSData，要麼將其轉換爲Base64字符串，然後在sqlite中打包Base64字符串。

要存儲的NSData在SQLite作爲字節可以參考下面的聯繫：

1）How to retrieve string from NSData stored in sqlite?

2）Retrieve nsdata from sqlite stored in Blob data type for iPhone App

要存儲的NSData SQLite中爲Base64則可以使用下面的Base64庫，它是非常容易使用。

https://github.com/nicklockwood/Base64

我們一個NSData的轉換爲Base64只使用下面的代碼：

NSString *aStrData = [theNSDataObject base64EncodedString]; 

然後你從數據庫讀取後的Base64編碼字符串轉換回NSData的象下面這樣：

NSData *theNSDataObject = [aStrData base64DecodedData]; 

我更喜歡使用Base64字符串是一種好方法，所以如果將來如果您想將圖像發送到任何Web服務，您也可以使用base64格式發送它。

Answer 2

//使用這個代碼插入

NSString *insertSQL = [NSString stringWithFormat:@"INSERT INTO <Table Name> (Image) VALUES (?)"]; 

     const char *insert_stmt = [insertSQL UTF8String]; 

     if(sqlite3_prepare_v2(contactDB, insert_stmt, -1, &statement, NULL)== SQLITE_OK) 
     { 

      sqlite3_bind_blob(statement, 1, [imageData bytes],(unsigned int) [imageData length], SQLITE_TRANSIENT); 
     } 

//使用此代碼從UIImagePicker檢索

if (sqlite3_open(dbpath, &contactDB) == SQLITE_OK) 
    { 

     NSString *querySQL = [NSString stringWithFormat: 
           @"SELECT * FROM <Table Name>" ]; 
     const char *query_stmt = [querySQL UTF8String]; 

     if (sqlite3_prepare_v2(contactDB, 
           query_stmt, -1, &statement, NULL) == SQLITE_OK) 
     { 
      while (sqlite3_step(statement) == SQLITE_ROW) 
      { 


       int blobBytesLength = sqlite3_column_bytes(statement, 1); 
       NSData *blobData = [[NSData alloc]initWithBytes:sqlite3_column_blob(statement, 1)length:blobBytesLength]; 

       UIImage *imagetest = [[UIImage alloc] initWithData:blobData];//this is your Image 
      } 
     }