blob

###数据库中提供了两种字段类型 Blob 和 Clob 用于存储大型字符串或二进制数据 Blob 采用单字节存储，适合保存二进制数据，如图片文件。 Clob 采用多字节存储，适合保存大型文本数据。 ###Oracle中处理BLOB/CLOB字段的方式比较特别，所以需要特别注意下面两点： 在Oracle JDBC中采用流机制对 BLOB/CLOB 进行读写操作，所以要注意不能在批处理中读写 BLOB/CLOB字段，否则将出现 Stream type cannot be used in batching 异常。 Oracle BLOB/CLOB 字段本身拥有一个游标（cursor），JDBC通过游标对Blob/Clob字段进行操作，在Blob/Clob字段创建之前，无法获取其游标句柄，会出现 Connection reset by peer: socket write error 异常。 正确的做法是：首先创建一个空 Blob/Clob 字段，再从这个空 Blob/Clob字段获取游标，例如下面的代码： PreparedStatement ps = conn.prepareStatement( " insert into PICTURE(image,resume) values(?,?) " ); // 通过oralce.sql.BLOB/CLOB.empty_lob(

We have an app using Phonegap 3.6.3 and built with Phonegap build . As part of this app, we need to download a file onto the device of the user. The file might be a .pdf, an image or any binary file. We hope to download the file with a blob:file link in the app, and not use a plugin such as file-transfer. The file is converted from Base64 data and a Blob object is created. An objectURL is generated through window.URL.createObjectURL() and this is added to the href attribute of an a element. The DOM contains the following <a href="blob:file%3A///cf2e336c-8c10-4e54-9e99-26f7d5a0115f" download="1

i am using html5 canvas to alter an image. i would like to be able to use the resulting canvas image data to send to the server using the same file upload field . (alternately, it could be by adding a new field to the existing form ). i have converted the image to a Blob, but it seems that the only way to send this type of data to the server is using FormData, which requires its own (separate) XMLHttpRequest. this is not desirable for me. ( context : i am trying to essentially hijack any arbitrary file input field in any arbitrary form on a page. consequently, i do not want to alter the method

Greetings I need to display images stored in BLOB database fields in a LISTVIEW or similar widget from Yii2 I have the actionCreate that saves the image in table named honra as a BLOB public function actionCreate() { $model = new Honra(); if ($model->load(Yii::$app->request->post()) && $model->save()) { $file = UploadedFile::getInstance($model,'binaryfile'); $model->binaryfile=$file; return $this->redirect(['view', 'id' => $model->id]); } else { return $this->render('create', [ 'model' => $model, ]); } } I also have the model named Honra class Honra extends \yii\db\ActiveRecord{ public static

I'm trying to convert a blob (created with zip.js ) to a base64 and persist it in the websql database. Then I would also like to do this process the other way around. Anyway, my test code (without the compression) looks something like: var blob = new Blob([data], { type : "text/plain" }); blobToBase64(blob, function(b64) { // convert BLOB to BASE64 var newBlob = base64ToBlob(b64) ; // convert BASE64 to BLOB console.log(blob.size + " != " + newBlob.size) ; }); see a working example: http://jsfiddle.net/jeanluca/4bn5G/ So, the strange thing is, that it works in Chrome, but not in Safari (als not