search

google-code-export / sqlite-manager

Automatically exported from code.google.com/p/sqlite-manager
1 stars 0 forks source link

BLOB suggestion - view images from db #48

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago 
First, congratulations for the excellent tool.

1. Can I add a blob in a column of another kind? I think I should have a
lock for this.
2. It would be an interesting tool for viewing images from DB.

Excuse my English, it was translated by Google. =P

Original issue reported on code.google.com by marciel....@gmail.com on 16 May 2008 at 11:12

GoogleCodeExporter commented 9 years ago 
Thanks for the encouragement.

1. The datatype for the column does not restrict what data may be put in that 
column.
In SQLite version 3, the type of a value is associated with the value itself, 
not
with the column or variable in which the value is stored. (This is sometimes 
called
manifest typing.) The type affinity of a column is the recommended type for data
stored in that column. The key here is that the type is recommended, not 
required.
Any column can still store any type of data, in theory. Read
http://sqlite.org/datatype3.html from where I have quoted the above.

But your suggestion, nevertheless, is worth considering.

2. Let me examine this.

No problem with your English at all.

Original comment by mrinal.k...@gmail.com on 17 May 2008 at 2:42

GoogleCodeExporter commented 9 years ago

Original comment by mrinal.k...@gmail.com on 25 May 2008 at 6:53

GoogleCodeExporter commented 9 years ago 
Would love to see the functionality to view images stored in BLOBs as well. 
Commercial products provide this. Would it possible to auto-detect file type 
based on magic bytes in the data?
Open a new tab with the image or show inside a popup window on hover? Not sure 
what would be the best from usability POV.

http://www.sqlmaestro.com/products/sqlite/maestro/help/06_05_00_blob_viewer/

Original comment by osm.tool...@gmail.com on 1 Jul 2012 at 10:31

GoogleCodeExporter commented 9 years ago 
Seems that images could be identified by examining BLOB type columns for file 
signatures, eg:

GIF image files have the ASCII code for "GIF89a" (47 49 46 38 39 61) or 
"GIF87a" (47 49 46 38 37 61)

JPEG image files begin with FF D8 and end with FF D9. JPEG/JFIF files contain 
the ASCII code for "JFIF" (4A 46 49 46) as a null terminated string. JPEG/Exif 
files contain the ASCII code for "Exif" (45 78 69 66) also as a null terminated 
string, followed by more metadata about the file.

PNG image files begin with an 8-byte signature which identifies the file as a 
PNG file and allows detection of common file transfer problems: \211 P N G \r 
\n \032 \n (89 50 4E 47 0D 0A 1A 0A). That signature contains various newline 
characters to permit detecting unwarranted automated newline conversions, such 
as transferring the file using FTP with the ASCII transfer mode instead of the 
binary mode.[5]

See https://en.wikipedia.org/wiki/Magic_number_(programming)

Once detected, we would need to determine how to render, eg:
Full Size, Full Size scaled to Thumbnail, actual Thumbnail, [filetype], [BLOB], 
etc.

This would be a very useful feature...

Original comment by linux.us...@gmail.com on 26 Sep 2012 at 7:56