blob

问题 I have tried to create a Blob in Node.js. First just this: var b = new Blob(['hi', 'constructing', 'a', 'blob']); This fails with ReferenceError: Blob is not defined Then I tried with the blob module (the two lines of code is from the example for this module, see https://www.npmjs.com/package/blob): var Blob = require('blob'); var b = new Blob(['hi', 'constructing', 'a', 'blob']); This fails with TypeError: Blob is not a constructor How can I do it? 回答1: Node.js doesn't have Blob , it uses

问题 I am trying to play an audio file that has been stored in LocalForage of my Meteor Android App. LocalForage.getItem(track_id, (err, value)=>{ if(err) throw err; //the loaded value is an arraybuffer of an m4a file let blob = new Blob([value]); let url = (window.URL || window.webkitURL || window || {}).createObjectURL(blob); let testAudio = new Audio(url); testAudio.play().then(()=>{console.log("play successful")}).catch((err)=>{console.error(err)}); }); Before, I passed the url to an Instance

问题 I am trying to allow users to choose a file from local hard disk and to insert it with java in a Oracle Data base as BLOB value. The setBinaryStream did not allow big files. with the setBlob I have no way to convert the file to a blob. Is the import of a blob file from the DB then overwrite it the unique solution?. Regards, Haythem 回答1: This is a suggestion that I've used before In essence a file is an array of bytes, what you can do is to read the file data and use PreparedStatement.setBytes

问题 I wish to extract just the first 1024 bytes of a stored blob and not the whole file. The reason for this is I want to just extract the metadata from a file as quickly as possible without having to select the whole blob. I understand the following: select dbms_lob.substr(file_blob, 16,1) from file_upload where file_upload_id=504; which returns it as hex. How may I do this so it returns it in binary data without selecting the whole blob? Thanks in advance. 回答1: DBMS_LOB.SUBSTR will, for a BLOB,

问题 So, the gist is, I'm downloading uploaded files to the db to show them, at least most of them, inside a iframe This is the code: var ancho = $(window).width() * 0.90; var alto = $(window).height() * 0.90; $("#DialogoImagen").dialog({ show: { effect: 'blind' }, hide: { effect: 'blind' }, width: ancho, height: alto, resizable: true, draggable: true, title: '', modal: true, position: { my: "center", at: "top", of: window } }); $("#DialogoImagen").children().remove(); var iframe = $("<iframe

问题 How can we use substring, trim, length operations on some text of blob datatype. And how can we update a column of blob datatype using query? Thanks, 回答1: With difficulty! First of all, which of the 4 various types of blob are you discussing: BYTE TEXT BLOB CLOB These come in pairs (like Sith Lords): there is a binary version (BYTE, BLOB) and a text version (TEXT, CLOB). There's also another pairing: old (BYTE, TEXT) and newer (BLOB, CLOB). The BYTE and TEXT types were introduced with

问题 I have a simple (example) script to upload a file into the database (Oracle, if it matters): <cfscript> param string filename; if ( FileExists( filename ) ) { result = new StoredProc( datasource = "ds", procedure = "FILE_UPLOAD", result = "NA", parameters = [ { value = FileReadBinary( filename ), type = "in", cfsqltype = "CF_SQL_BLOB" } ] ).execute(); } </cfscript> However, the ColdFusion CFML Reference states for FileReadBinary( filepath ) : Note: This action reads the file into a variable

问题 I'm trying to create a file preview system. When the user click in a upload button and select files, I use the HTML5 FILE API to get all the file info and create a thumbnail for the file. The user can cancel the upload of some of thoose files and add more files too. What I have now is this: <p><input id="blob" name="blob" type="file" size="75" multiple /></p> <form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>"> <input id="blobtype" name="blobtype" type="text" size="20" /> <input

问题 I have created a table with Blob datatype but I do not know how to insert values into the table or view the table content using SQL*Plus. Please help me. 回答1: It depends on what kind of data you want put into a BLOB. Let's consider the table: create table b1(id number , b blob); If your data represented as hex-string you should use TO_BLOB function insert into b1 values(1,to_blob('FF3311121212EE3a')); SQLPLUS also shows BLOBs as hex-string select * from b1; ----- -----------------------------

问题 this http://jsfiddle.net/bCRm3/17/ (Kendo grid export to csv) works fine in firefox, chrome and IE11 in ie9 im getting blob = new Blob([csv], { type: 'text/csv;charset=utf-8' }); //Blob.js saveAs(blob, fileName); //FileSaver.js 'Blob' is undefined show, line 141 character 17 is there a way around this for ie9? (im not sure if this works on ie10) 回答1: Check Blob object browser compatibility: Browser compatibility Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit) 20 13.0 (13.0) 10