blob

Write file from BLOB mysql python

由 馋奶兔 提交于 2019-12-08 02:58:30
问题 I'm trying to get a file from a database and write it to disk. The file is stored as BLOB. Now I have the following code: #!/usr/bin/python import MySQLdb db2 = MySQLdb.connect(host="localhost", user="root", passwd="root", db="digit") cur = db2.cursor() #get the name of the file cur.execute("SELECT Name FROM ContentFiles WHERE ID=3") nombre = cur.fetchone() #open file and write into. with open(nombre[0],"wb") as output_file: cur.execute("SELECT File FROM ContentFiles WHERE ID=3") ablob = cur

Counting number of Blobs via MatLab

由 て烟熏妆下的殇ゞ 提交于 2019-12-08 02:51:16
问题 I am trying to experiment how MatLab image processing methods work when I came across this problem. Please refer to the 2 images below The images are actually the sides of books: The image on the right shows a failed effort to bound and count the number of object. The code is as follows: BW2=~BW2; imshow(BW2) B = bwboundaries(BW2); imshow(BW2) text(10,10,strcat('\color{green}Objects Found:',num2str(length(B)))) hold on for k = 1:length(B) boundary = B{k}; plot(boundary(:,2), boundary(:,1), 'g

Why does Git store (and hash) blob size in the blob file?

由 。_饼干妹妹 提交于 2019-12-08 02:23:43
问题 Git's blob object file format is blob <size string>\0<data> . The blob-identifying SHA-1 hash is calculated not from the blob contents alone, but from the header-augmented blob data (as described above). As a purist I do not like that architecture. It mixes the universal property of the data (its SHA1 hash) with some git-specific header. Another advantage of pure-data blob storage is that the files can be added to the index using "copy-on-write" instead of copying the whole file. The required

How to download a file generated with JavaScript, avoiding automatic opening of Chome?

由 六眼飞鱼酱① 提交于 2019-12-08 02:07:48
问题 I am developing a JavaScript little webmail. I receive from the server a Base64-encoded string, that represents a file (it could be whatever type). I decode the string, a map it to a Uint8Array , and with it, I generate a Blob object with I create a data URI with FileReader.readAsDataURL(blob) Until here is pretty straightforward, but I am having problem with the download part. I put the DataURI in window.open(dataURI) But chrome opens a new window and display my image, or my text. But I need

不依赖驱动更新blob字段

由 霸气de小男生 提交于 2019-12-07 22:10:00
不依赖驱动更新blob字段，场景如下： tomcat发布到weblogic上，使用weblogic的连接池，就抛错了，如下： java.lang.ClassCastException: weblogic.jdbc.wrapper.Blob_oracle_sql_BLOB 开发代码如下： oracle.sql.BLOB blob = (oracle.sql.BLOB) rs.getBlob("TRANSFERDATA"); BufferedOutputStream bos = new BufferedOutputStream(blob.getBinaryOutputStream()); bos.write(define.getBytes("GBK")); 后来查了一下，原因是通过weblogic连接池取出的连接取出的blob对象是weblogic封装过的OracleThinBlob，而不是oracle.sql.BLOB。然后又看了一下OracleThinBlob的方法与oracle.sql.BLOB类似，所以采用了下面的写法，避免异常： Object obj = rs.getBlob("TRANSFERDATA"); Class clazz = obj.getClass(); Method method = clazz.getMethod("getBinaryOutputStream

Create image serving URL for new Blob file

由 感情迁移 提交于 2019-12-07 20:35:27
问题 After using the ImagesService to transform an uploaded image, I would like to store it back into a new Blob file and make it available through getServingUrl() as provided by the ImagesService. Storing the image in a new AppEngineFile as described here works fine and I am able to open and view it locally using the dev server. However when passing the blobKey for the new AppEngineFile to ImagesService.getServingUrl() a java.lang.IllegalArgumentException: Could not read blob. exception is thrown

BLOB in MySQL view instead of the proper data

由 好久不见. 提交于 2019-12-07 20:17:07
问题 I created a MySQL view using UNION ALL from two tables so that I would get the same column names for the same data in those tables (i.e. tbl1.author2 AS translator ... tbl2.translator AS translator ) and so on, the problem is when I try to select something from that view, half of the data comes out as BLOB , instead of the original value. The view definition is: SELECT e.id AS prod_id, e.price_vat AS price_vat, e.product AS title, e.authors AS author, e.isbn AS isbn, e.ean AS ean, e.page

enable caching of images specifying a modified date

由 橙三吉。 提交于 2019-12-07 19:33:07
问题 I've a jsp page which loads many images. I'd like to cache the images for faster loading. I'll explain my idea, please correct it if it's wrong. I'm calling the picture loading servlet for each image and return as a BLOB. My idea is to add a modified date with the image and the other values like Last-Modified, expires, Cache-control and max age. And thereby make the browser understand if the image changes. But how can i append a modified date to a BLOB? Or is there some better ideas to make

JDBC--BLOB

由 ﹥＞﹥吖頭↗ 提交于 2019-12-07 19:27:00
一、BLOB（二进制数据） 1. MySQL中，BLOB是一个二进制大型对象，是一个可以存储大量数据的容器，它能容纳不同大小的数据。 2.BLOB字段适用于存储大量的二进制数据，如图像、视频、音频，文件等。 3. MySQL的四种BLOB类型(除了在存储的最大信息量上不同外，他们是等同的)： 4. 实际使用中根据需要存入的数据大小定义不同的BLOB类型。需要注意的是：如果存储的文件过大，数据库的性能会下降。 二、存储和读取BLOB文件 （1）向数据库存储BLOB文件 主要操作： InputStream inputStream = new FileInputStream("阿阮.jpg"); preparedStatement.setBlob(7,inputStream); 例： @Test public void test14() { Connection conn = null; PreparedStatement preparedStatement = null; try { //获取数据库连接 conn = JDBCTools.getConnection(); //设置 SQL语句 String sql = "INSERT INTO Student(Sno, Sname, Ssex, Sage, Sdept, S_entrance, S_picture) " +

Compress GAE Blob images using Python Base64?

由 ∥☆過路亽．° 提交于 2019-12-07 18:41:41
问题 I'm pulling a JSON request of 20 random thumbnails to an iPhone application. At the moment I'm simply including the image thumb URLs in the JSON array (see below), then the iPhone goes out to get each image. This is really slow. Original JSON Request: { "item_list": [ { "item_name": "Item One", "user_item_thumb": "http://localhost:8080/i/agpwaGluZ28tYXBwcg4LEghJdGVtVXNlchgPDA/67x67", }, { "item_name": "Item Two", "user_item_thumb": "http://localhost:8080/i
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