I tried to use UTF-8 and ran into trouble.
I have tried so many things; here are the results I have gotten:
???? instead of Asian characters. Even for European text, I got Se?or for Señor.
Strange gibberish (Mojibake?) such as Señor or 新浪新闻 for 新浪新闻.
Black diamonds, such as Se�or.
Finally, I got into a situation where the data was lost, or at least truncated: Se for Señor.
Even when I got text to look right, it did not sort correctly.
What am I doing wrong? How can I fix the code? Can I recover the data, if so, how?
This problem plagues the participants of this site, and many others.
You have listed the five main cases of CHARACTER SET troubles.
Best Practice
Going forward, it is best to use CHARACTER SET utf8mb4 and COLLATION utf8mb4_unicode_520_ci. (There is a newer version of the Unicode collation in the pipeline.)
utf8mb4 is a superset of utf8 in that it handles 4-byte utf8 codes, which are needed by Emoji and some of Chinese.
Outside of MySQL, "UTF-8" refers to all size encodings, hence effectively the same as MySQL's utf8mb4, not utf8.
I will try to use those spellings and capitalizations to distinguish inside versus outside MySQL in the following.
Overview of what you should do
Have your editor, etc. set to UTF-8.
HTML forms should start like <form accept-charset="UTF-8">.
Have your bytes encoded as UTF-8.
Establish UTF-8 as the encoding being used in the client.
Have the column/table declared CHARACTER SET utf8mb4 (Check with SHOW CREATE TABLE.)
<meta charset=UTF-8> at the beginning of HTML
Stored Routines acquire the current charset/collation. They may need rebuilding.
UTF-8 all the way through
More details for computer languages (and its following sections)
Test the data
Viewing the data with a tool or with SELECT cannot be trusted.
Too many such clients, especially browsers, try to compensate for incorrect encodings, and show you correct text even if the database is mangled.
So, pick a table and column that has some non-English text and do
SELECT col, HEX(col) FROM tbl WHERE ...
The HEX for correctly stored UTF-8 will be
For a blank space (in any language): 20
For English: 4x, 5x, 6x, or 7x
For most of Western Europe, accented letters should be Cxyy
Cyrillic, Hebrew, and Farsi/Arabic: Dxyy
Most of Asia: Exyyzz
Emoji and some of Chinese: F0yyzzww
More details
Specific causes and fixes of the problems seen
Truncated text (Se for Señor):
The bytes to be stored are not encoded as utf8mb4. Fix this.
Also, check that the connection during reading is UTF-8.
Black Diamonds with question marks (Se�or for Señor);
one of these cases exists:
Case 1 (original bytes were not UTF-8):
The bytes to be stored are not encoded as utf8. Fix this.
The connection (or SET NAMES) for the INSERT and the SELECT was not utf8/utf8mb4. Fix this.
Also, check that the column in the database is CHARACTER SET utf8 (or utf8mb4).
Case 2 (original bytes were UTF-8):
The connection (or SET NAMES) for the SELECT was not utf8/utf8mb4. Fix this.
Also, check that the column in the database is CHARACTER SET utf8 (or utf8mb4).
Black diamonds occur only when the browser is set to <meta charset=UTF-8>.
Question Marks (regular ones, not black diamonds) (Se?or for Señor):
The bytes to be stored are not encoded as utf8/utf8mb4. Fix this.
The column in the database is not CHARACTER SET utf8 (or utf8mb4). Fix this. (Use SHOW CREATE TABLE.)
Also, check that the connection during reading is UTF-8.
Mojibake (Señor for Señor):
(This discussion also applies to Double Encoding, which is not necessarily visible.)
The bytes to be stored need to be UTF-8-encoded. Fix this.
The connection when INSERTing and SELECTing text needs to specify utf8 or utf8mb4. Fix this.
The column needs to be declared CHARACTER SET utf8 (or utf8mb4). Fix this.
HTML should start with <meta charset=UTF-8>.
If the data looks correct, but won't sort correctly, then
either you have picked the wrong collation,
or there is no collation that suits your need,
or you have Double Encoding.
Double Encoding can be confirmed by doing the SELECT .. HEX .. described above.
é should come back C3A9, but instead shows C383C2A9
The Emoji 👽 should come back F09F91BD, but comes back C3B0C5B8E28098C2BD
That is, the hex is about twice as long as it should be.
This is caused by converting from latin1 (or whatever) to utf8, then treating those
bytes as if they were latin1 and repeating the conversion.
The sorting (and comparing) does not work correctly because it is, for example,
sorting as if the string were Señor.
Fixing the Data, where possible
For Truncation and Question Marks, the data is lost.
For Mojibake / Double Encoding, ...
For Black Diamonds, ...
The Fixes are listed here. (5 different fixes for 5 different situations; pick carefully): http://mysql.rjweb.org/doc.php/charcoll#fixes_for_various_cases
I had similar issues with two of my projects, after a server migration. After searching and trying a lot of solutions, I came across with this one:
mysqli_set_charset($con,"utf8mb4");
After adding this line to my configuration file, everything works fine!
I found this solution for MySQLi—PHP mysqli set_charset() Function—when I was looking to solve an insert from an HTML query.
I was also searching for the same issue. It took me nearly one month to find the appropriate solution.
First of all, you will have to update you database will all the recent CHARACTER and COLLATION to utf8mb4 or at least which support UTF-8 data.
For Java:
while making a JDBC connection, add this to the connection URL useUnicode=yes&characterEncoding=UTF-8 as parameters and it will work.
For Python:
Before querying into the database, try enforcing this over the cursor
cursor.execute('SET NAMES utf8mb4')
cursor.execute("SET CHARACTER SET utf8mb4")
cursor.execute("SET character_set_connection=utf8mb4")
If it does not work, happy hunting for the right solution.
Set your code IDE language to UTF-8
Add <meta charset="utf-8"> to your webpage header where you collect data form.
Check your MySQL table definition looks like this:
CREATE TABLE your_table (
...
) ENGINE=InnoDB DEFAULT CHARSET=utf8
If you are using PDO, make sure
$options = array(PDO::MYSQL_ATTR_INIT_COMMAND=>'SET NAMES utf8');
$dbL = new PDO($pdo, $user, $pass, $options);
If you already got a large database with above problem, you can try SIDU to export with correct charset, and import back with UTF-8.
Depending on how the server is setup, you have to change the encode accordingly. utf8 from what you said should work the best. However, if you're getting weird characters, it might help if you change the webpage encoding to ANSI.
This helped me when I was setting up a PHP MySQLi. This might help you understand more: ANSI to UTF-8 in Notepad++
SELECT * FROM `employee` WHERE `name` LIKE "%شريف%"
Above query works fine and find the element by phpmyAdmin query but using it inside JavaFX doesn't get it.
And get the english searchs, So what I need to add in java to permit me search by Arabic.
As per my above comments, I guess it to be a encoding - decoding issue of Java and has nothing specific to do with JavaFX and I also assume that you are not getting any exceptions. You have to use a proper standard while inserting as well as retrieving data. Helpful information is there at , How to store arabic text in mysql database using python?
Refer this article to work only on bytes so your application is always properly internationalized , Byte Encodings and Strings
Refer this one too as how to set encoding in Java , How can I insert arabic word to mysql database using java
Your console might be UTF8 enabled so you are able to match strings there and see Arabic characters.
Hope it helps.
I tried using Teradata fastload
Here is the sample file that they provide on the official website
L_INDEX,L_TIMESTAMP,L_TEXT
1,2010-08-11 13:19:05.1,some text
2,2010-08-11 13:19:05.1,
3,2010-08-11 13:19:05.1,more text
4,,text
5,,
It runs perfect with the above file
Then I modified ONLY the first row . So that some text became "some, text" . The following is a perfectly legit csv
L_INDEX,L_TIMESTAMP,L_TEXT
1,2010-08-11 13:19:05.1,"some, text" // this row was slightly modified
2,2010-08-11 13:19:05.1,
3,2010-08-11 13:19:05.1,more text
4,,text
5,,
However I got an error saying that the first column contains 4 values but only 3 values were expected
As far as I understand I must specify text qualifier " . How can I do this ?
I read documentation but nothing is mentioned about this .
According to the FastLoad Utility documentation pertaining to the selection of a delimiter for use with the SET RECORD command and a VARTEXT layout:
Any character sequence that appears in the data cannot be used as a
delimiter. No control character other than a tab character can be used
in a delimiter.
This would likely extend to the use of the FastLoad API mechanism leveraged within the Teradata JDBC driver.
EDIT
FastLoad has been around for 15+ years and does what it was intended to well -- load lots of data fast. Your other options would be to create a fixed length record where you do not have to rely on a delimiter or create an INMOD to parse the file as it is streamed into FastLoad.
Other alternatives include MultiLoad, Teradata Parallel Transport, TPUMP, or a proper ETL tool to load your data. Each have their own advantages and disadvantages that have to be considered with the format of the data which is being supplied to the environment.
I am reading a column from database using rs.getString() method , the column has some multibyte data.
When retrieved through rs.getString() , the data get garbled and all multibyte characters appear as ??????.
Please suggest what should be done.
I have tried using -Dfile.encoding=UTF8 , but that does not work out.
Do you have the language sets installed on the machine you are trying to decode? Can you get the data out correctly using any methods?
how to read unicode text from java resultset?
rs.getString() returns a Java String which is Unicode by definition.
If you get mangled characters, you have to configure your database driver to use the right encoding for the connection to the database.
Just read the strings. All strings in Java are unicode already. If you're having problems, then:
It could be a diagnostic problem - you may be reading the right data out of the ResultSet but displaying it so it looks like you haven't read it properly
It could be a configuration problem - there may be something you need to do when connecting to the database so that it determines the right encoding to use
It could be a database problem - the database may not be configured to store full Unicode data
It could be a database schema problem - the particular column you're using may be configured using a column type which doesn't support full Unicode
It could be a problem in the data, e.g. with another program incorrectly submitting data.
I've seen all of these before now. You should use detailed logging (e.g. of the individual characters, in hex) to work out whether you've got the data correctly or not - that will tell you where to look next.
If you are using DataSource (f.e. com.mysql.jdbc.jdbc2.optional.MysqlDataSource) you can directly set channel encoding to UTF8 like ds.setEncoding("UTF-8")