There is a MySQL backup file which is a huge file - about 3 GB. There is one table that has a LONGBLOB column that stores JPEG image data.
The file imports successfully if done from MySQL Workbench - Data Import/Restore.
I need to open this file and extract the first few lines (about two rows of INSERTs of the table with the image data) so that I can test if another program can import this data into another MySQL database.
I tried opening the file with EmEditor (which is good at opening large files) and then copy/paste only upto one Insert statement of the script into a new file (upto about line 25, because the table in question is the first table in the backup script), and then Paste the selection into a new file.
Here comes the problem:
However this messes up the encoding (even though I save as utf8). I realize this when I try to import (restore) this new file (again using MySQL Workbench) into a MySQL database, the restore goes ahead without errors, but the JPEG images in the blob column are now destroyed/corrupted.
My guess is that the encoding is different between the original file and new file.
EmEditor does not show the encoding on the original file, there is an option to detect, and it detects it as 'UTF8 Unsigned'. But when saving I save it as UTF8. I tried also saving as ANSI, ISO8859 (windows default), etc, etc.. but everytime the same result.
Do you have any solution for this particular problem? ie I want to only cut the first few lines of the huge backup file and save to a new file keeping the encoding the same, so that the images (blobs) are not changed. Is there any way this can be done with EmEditor (ie do I have the wrong approach [ie Cut-Paste]?) Is there any specialized software that can do this? How can I diagnose what is going wrong here?
Thanks for any responses.
this messes up the encoding (even though I save as utf8)
UTF-8 is not a good choice for arbitrary binary data. There are many sequences of high-bytes which are not valid in UTF-8, so you will mangle them at some point during the load-alter-save process.
If you load the file using an encoding that maps every single byte to a unique character, and re-save the file using that same encoding, you should preserve the original content(*). ISO-8859-1 is the encoding usually chosen for this purpose, since it simply maps each byte 0..0xFF to the Unicode code point with the same number.
(*: assuming the editor is binary-safe with regard to other tricky points like nulls, \n/\r and other control characters... I believe EmEditor can be.)
When opening the original file in EmEditor, trying selecting the encoding as Binary (ASCII View). The Binary (ASCII View) will, as bobince said, map each byte to a unique character and preserve that when you save the file. I think this should fix your problem.
Related
I am trying to upload a .csv file into Workbench using the Table Data Import Wizard.
I receive the following error whenever attempting to load it:
Unhandled exception: 'ascii' codec can't decode byte 0xc3 in position 1253: ordinal not in range(128)
I have tried previous solutions that suggested I encode the .csv file as a MS-DOS csv and as a UTF-8 csv. Neither have worked for me.
Attempting to change the data in the file would not be feasible since its made up of thousands of cells, so it would quite impractical. Is there anything that can be done to resolve this?
What was after the C3? What should have been there?
C3, when interpreted as "latin1" is à -- an unlikely character.
More likely is a 2-byte UTF-8 code that starts with C3. This includes the accented letters of Western European languages. Example é, hex C3A9.
You tried "UTF-8 csv" -- Please provide the specifics of how you tried it. What settings in the Wizard, etc.
Probably you should state that the data is "UTF-8" or utf8mb4, depending on whether you are referring to outside or inside MySQL.
Meanwhile, if you are loading the data into an existing "table", let's see SHOW CREATE TABLE. It should probably not say "ascii" anywhere; instead, it should probably say "utf8mb4".
When I try to read a csv file in Octave I realize that the very first value from it is converted to zero. I tried both csvread and dlmread and I'm receiving no errors. I am able to open the file in a plain text editor and I can see the correct value there. From what I can tell, there are no funny hidden characters, spacings, or similar in the csv file. Files also contain only numbers. The only thing that I feel might be important is that I have five columns/groups that each have different number of values in them.
I went through the commands' documentation on Octave Forge and I do not know what may be causing this. Does anyone have an idea what I can troubleshoot?
To try to illustrate the issue, if I try to load a file with the contents:
1.1,2.1,3.1,4.1,5.1
,2.2,3.2,4.2,5.2
,2.3,3.3,4.3,
,,3.4,4.4
,,3.5,
Command window will return:
0.0,2.1,3.1,4.1,5.1
,2.2,3.2,4.2,5.2
,2.3,3.3,4.3,
,,3.4,4.4
,,3.5,
( with additional trailing zeros after the decimal point).
Command syntaxes I'm using are:
dt = csvread("FileName.csv")
and
dt = dlmread("FileName.csv",",")
and they both return the same.
Your csv file contains a Byte Order Mark right before the first number. You can confirm this if you open the file in a hex editor, you will see the sequence EF BB BF before the numbers start.
This causes the first entry to be interpreted as a 'string', and since strings are parsed based on whether there are numbers in 'front' of the string sequence, this is parsed as the number zero. (see also this answer for more details on how csv entries are parsed).
In my text editor, if I start at the top left of the file, and press the right arrow key once, you can tell that the cursor hasn't moved (meaning I've just gone over the invisible byte order mark, which takes no visible space). Pressing backspace at this point to delete the byte order mark allows the csv to be read properly. Alternatively, you may have to fix your file in a hex editor, or find some other way to convert it to a proper Ascii file (or UTF without the byte order mark).
Also, it may be worth checking how this file was produced; if you have any control in that process, perhaps you can find why this mark was placed in the first place and prevent it. E.g., if this was exported from Excel, you can choose plain 'csv' format instead of 'utf-8 csv'.
UPDATE
In fact, this issue seems to have already been submitted as a bug and fixed in the development branch of octave. See #58813 :)
When I am opening a csv file containing Chinese characters, using Microsoft Excel, TextWrangler and Sublime Text, there are some Chinese words, which cannot be displayed properly. I have no ideas why this is the case.
Specifically, the csv file can be found in the following link: https://www.hkex.com.hk/eng/plw/csv/List_of_Current_SEHK_EP.CSV
One of the word that cannot be displayed correctly is shown here:
As you can see a ? can be found.
Using mac file command as suggested by
http://osxdaily.com/2015/08/11/determine-file-type-encoding-command-line-mac-os-x/ tell me that the csv format is utf-16le.
I am wondering what's the problem, why I cannot read that specific text?
Is it related to encoding? Or is it related to my laptop setting? Trying to use Mac and windows 10 on Mac (via Parallel Desktop) cannot display the work correctly.
Thanks for the help. I really want to know why this specific text cannot be displayed properly.
The actual name of HSBC Broking Securities is:
滙豐金融證券(香港)有限公司
The first character, U+6ED9 滙, is one of the troublesome HKSCS characters: characters that weren't available in standard pre-Unicode Big-5, which were grafted on in incompatible ways later.
For a while there was an unfortunate convention of converting these characters into Private Use Area characters when converting to Unicode. This data was presumably converted back then and is now mangled, replacing 滙 with U+E05E Private Use Area Character.
For PUA cases that you're sure are the result of HKSCS-compatibility-bodge, you can convert back to proper Unicode using this table.
Currently working on a Data Mining project using my own dataset I had found using Weka. The only issue is that taking my file from csv format and converting it into arff format is causing issues.
java.io.IOException: wrong number of values. Read 2, expected 5, Read Token[EOL], line 3
This is the error I am getting. I have browsed around online looking for similar issues and have tried removing all quotes and special characters that throw this exception. Every place I looked told me to remove special characters and I believe there are none left. The link to my dataset is here : https://docs.google.com/spreadsheets/d/1xqEe7MZE9SdKB_yvFSgWeSVYuDrq0b31Eu5oECNbGH0/edit#gid=1736568367&vpid=A1
This is the first three lines of my file where the first is the attribute names, file is separated by commas in note
Inequality Adjusted HPI Rank,Sub Region,Inequality Adjusted Life Expectancy,Inquality Adjusted Well being,Footprint
,Inequality adjusted HPI
1,1,73.1,6.9,2.5,48.2
2,6,65.17333333,5.487667631,1.390974448,45.97489063
If you open your file with a text editor, you will see that Footprint has quotes around it. Delete the quotes and you are good to go!
Weka is normally not that good in reading CSV files that include special characters, and ARFF files are normally easier to use. Therefore, in such cases, the easiest way is to convert your CSV file to an ARFF file using R ("RWeka" and "foreign" libraries can handle this conversion).
There is also another possibility. I was creating my CSV file and the header had a different number of elements compared to the rest of the data. So, check the header as well...!
We have an MS Access .mdb file produced, I think, by an Access 2000 database. I am trying to export a table to SQL with mdbtools, using this command:
mdb-export -S -X \\ -I orig.mdb Reviewer > Reviewer.sql
That produces the file I expect, except one thing: Some of the characters are represented as question marks. This: "He wasn't ready" shows up like this: "He wasn?t ready", only in some cases (primarily single/double curly quotes), where maybe the content was pasted into the DB from MS Word. Otherwise, the data look great.
I have tried various values for "export MDB_ICONV=". I've tried using iconv on the resulting file, with ISO-8859-1 in the from/to, with UTF-8 in the from/to, with WINDOWS-1250 and WINDOWS-1252 and WINDOWS-1256 in the from, in various combinations. But I haven't succeeded in getting those curly quotes back.
Frankly, based on the way the resulting file looks, I suspect the issue is either in the original .mdb file, or in mdbtools. The malformed characters are all single question marks, but it is clear that they are not malformed versions of the same thing; so (my gut says) there's not enough data in the resulting file; so (my gut says) the issue can't be fixed in the resulting file.
Has anyone run into this one before? Any tips for moving forward? FWIW, I don't have and never have had MS Access -- the file is coming from a 3rd party -- so this could be as simple as changing something on the database, and I would be very glad to hear that.
Thanks.
Looks like "smart quotes" have claimed yet another victim.
MS word takes plain ascii quotes and translates them to the double-byte left-quote and right-quote characters and translates a single quote into the double byte apostrophe character. The double byte characters in question blelong to to an MS code page which is roughly compatable with unicode-16 except for the silly quote characters.
There is a perl script called 'demoroniser.pl' which undoes all this malarky and converts the quotes back to plain ASCII.
It's most likely due to the fact that the data in the Access file is UTF, and MDB Tools is trying to convert it to ascii/latin/is0-8859-1 or some other encoding. Since these encodings don't map all the UTF characters properly, you end up with question marks. The information here may help you fix your encoding issues by getting MDB Tools to use the correct encoding.