Related
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 (There is a newer version of the Unicode collation in the pipeline.)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++
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++
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++
I have a problem with sorting MYSQL result..
SELECT * FROM table WHERE something ORDER BY column ASC
column is set to utf8_unicode_ci..
As a result I first get rows which have column starting with Bosnian letters and then the others after that..
šablabl
šeblabla
čeblabla
aaaa
bbaa
bbb
ccc
MYSQL version is 5.1.61
Bgi is right. You need to use an appropriate collation. Unfortunately, MySQL doesn't have a Central European unicode collation yet. MariaDb, the MySQL fork being maintained by MySQL's creators, does.
So you can convert your text from utf8 to latin2 and then order with a Central European collating sequence. For example.
SELECT *
FROM tab
ORDER BY CONVERT(text USING latin2) COLLATE latin2_croatian_ci
See this fiddle: http://sqlfiddle.com/#!2/c8dd4/1/0
It is because the way of unicode is made. All the "normal" latin characters got back the same numerical correspondance they had in ASCII, and other characters from other cultures were added after. That means if your alphabet has other characters than the 26 regular ASCII ones, it wont appear in the correct order in Unicode.
I think you should try to change the collation on your column (maybe you'll have to change the charset also, but maybe not).
Use a Central European collation.
Good luck !!
If that's really what you see you have found a bug: utf8_unicode_ci is supposed to consider š equivalent to s and č equivalent to c!
In any case it's true that MySQL does not have great support of utf8 collations for Central European languages: you get only Czech, Slovak, and Slovenian. If none of those work for you, I guess you'll have to create your own utf8 collation, or use a non-Unicode character set and use the collations available there.
Older question and plenty of answers.
Maybe the way I deal with problems will help someone.
I use PDO. My DB is utf-8.
First - my db singleton code (relevant part of it). I set 'SET NAMES' to 'utf8' for all connections.
$attrib_array = array(PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES utf8');
if (DB_HANDLER)
$attrib_array[PDO::ATTR_ERRMODE] = PDO::ERRMODE_EXCEPTION;
self::$instance = new PDO(DB_TYPE.':host='.DB_HOST.';dbname='.DB_NAME, DB_USER, DB_PASS, $attrib_array);
Second - my sorting looks something like this - collation depends on language (sample shows polish):
ORDER BY some_column COLLATE utf8_polish_ci DESC
To make things more streamlined I use a constant, which I define in lang translation file, so when file is pulled, proper collation constant is set. Of course I have 'utf8_general_ci' as default. Example:
define('MY_LOCALIZED_COLLATE', 'COLLATE utf8_polish_ci');
Now, my (relevant part of) query looks like this:
" ... ORDER BY some_column " . MY_LOCALIZED_COLLATE . " DESC" ;
Above works in most cases.
If you are missing collation set, you may try to add one yourself.
More detailed info about creating such set - see here: http://dev.mysql.com/doc/refman/5.0/en/adding-collation.html
EDIT:
Just one more thing I noticed:
if you have list to sort in e.g. Polish
and you have to force proper collation for sorting (as described above)
and you use e.g. INT column as sorting vector
... then you better have collation set (e.g. to UTF8), or you will get SQL errors, e.g.:
"Syntax error or access violation: 1253 COLLATION 'utf8_polish_ci' is not valid for CHARACTER SET 'latin1'"
... strange, but true
Why won't mysql recognize é and a lot more characters including em dash (—) ?? This is driving me nuts. i keep getting such errors like Incorrect string value: '\xE9' for column
I am using mysql 5.5.6 , my tables are innodb and using collation utf8-default collation.
I don't know if this is important but I am doing bulk insert from a csv file which contains special characters and my fields are of type TEXT
I had a similar problem trying to SELECT ... WHERE table_col LIKE "%–%" (long dash) turned out it wasn't working because my .php file which was sending the query wasn't in UTF8 but instead in ANSI! Converting it to UTF8 did the trick!!
Your problem sounds like one I have dealt with in the past, and I concur with Synchro that the client connection settings may be where you need to look. You probably need to specify UTF8 character set when starting the connection.
I use PDO, and initiate the connection with this:
$this->dbConn = new PDO("mysql:host=$this->host;dbname=$this->dbname", $this->user, $this->pass, array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8"));
Before I started using PDO, I used this:
mysql_query("SET NAMES 'utf8'");
See http://dev.mysql.com/doc/refman/5.0/en/charset-connection.html
Just make sure the CSV file is in UTF8 and not the default ANSI. To do this open the csv file in notepad and using the save as option, ensure the encoding is in UTF8.
It's probably down to your PHP MySQL client's connection settings. Rob Allen's post can probably sort you out.
Rather than using a SET NAMES utf8 query, which the PHP docs explicitly warns against, there is a built-in function to do this for you in the mysqli extension: $mysqli->set_charset('utf8');.
An alternative explanation for bad characters if you're already doing this is that MySQL's utf8 charset isn't actually proper UTF-8... It only supports up to 3-byte characters and there are some increasingly common ones that use 4, specifically Emojis. Fortunately MySQL has a fix for this as of version 5.5.3: use the utf8mb4 charset instead.
On a related note, the sort order in the default utf8 charset (with the utf8_general_ci collation) has a number of problems that may affect you in, for example, German. The fix here is to use the utf8mb4_unicode_ci collation, which provides a more accurate, though slightly slower collation.