A solution to garbled pages in PHP and MySQL development

A solution to garbled pages in PHP and MySQL development_PHP Tutorial

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Release： 2016-07-21 15:54:39

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Generally speaking, there are two reasons for the appearance of garbled characters. First, it is due to an error in the encoding (charset) setting, which causes the browser to parse it with the wrong encoding, resulting in a messy "heavenly book" that fills the screen. Second, the file is read in the wrong format. Open the encoding and then save it. For example, a text file was originally encoded in GB2312, but it was opened in UTF-8 encoding and then saved. To solve the above garbled code problem, you first need to know which aspects of development involve encoding:

1. File encoding: refers to the encoding in which the page file (.html, .php, etc.) itself is saved. . Notepad and Dreamweaver will automatically recognize the file encoding when opening the page, so there will be less problems. However, ZendStudio does not automatically recognize the encoding. It will only open the file in a certain encoding according to the configuration of the preferences. If you accidentally open the file with the wrong encoding while working, and save it after making the modification, garbled characters will appear ( I feel it deeply).

2. Page declaration encoding: In the HTML code HEAD, you can use to tell the browser What encoding is used for the server web page? Currently, XXX mainly uses GB2312 and UTF-8 in Chinese website development.

3. Database connection encoding: refers to which encoding is used when performing database operations. When transmitting data from the database, you need to be careful not to confuse it with the encoding of the database itself. For example, the default encoding within MySQL is latin1 encoding, which means that Mysql stores data in latin1 encoding. Data transmitted to Mysql in other encodings will be converted into latin1. Encoding.

Knowing where encoding is involved in WEB development, you will also know the cause of garbled characters: the above three encoding settings are inconsistent. Since most of the various encodings are ASCII compatible, English symbols If it doesn't appear, Chinese is out of luck. Here are some common error situations and solutions:

1. The database uses UTF8 encoding, and the page declaration encoding is GB2312. This is the most common cause of garbled characters. When directly selecting data in a PHP script, the data will be garbled. You need to use it before querying:

mysql_query("SET NAMES GBK"); to set the MYSQL connection encoding and ensure that the page declaration encoding is consistent with the setting here The connection encoding is consistent (GBK is an extension of GB2312). If the page is UTF-8 encoded, you can use:
mysql_query("SET NAMES UTF8"); Note that it is UTF8 instead of the commonly used UTF-8. If the declared encoding is consistent with the internal encoding of the database, you do not need to set the connection encoding.
Note: In fact, the data input and output of MYSQL is more complicated than mentioned above. There are 2 default encodings defined in the MYSQL configuration file my.ini, respectively. It is the default-character-set in [client] and the default-character-set in [mysqld] to set the encoding used by the default client connection and the database internally. The encoding we specified above is actually the MYSQL client connection. The command line parameter character_set_client at the server time is used to tell the MYSQL server what encoding the client data received is used, instead of using the default encoding.

2. The page declaration encoding is inconsistent with the encoding of the file itself. This situation is very serious. It rarely happens, because if the encoding is inconsistent, what you see in the browser when you create the page is garbled code. More often, it is caused by fixing some small bugs after publishing, opening the page with the wrong encoding and then saving it. Or you use some FTP software to directly modify files online, such as CuteFTP. Due to incorrect software encoding configuration, the wrong encoding is converted.

3. Some friends who rent virtual hosts, even though the above three encodings are set correctly, there are still garbled characters. For example, if the web page is encoded in GB2312, it is always recognized as UTF-8 when opened by browsers such as IE. The HEAD of the web page has already stated that it is GB2312. After manually changing the browser encoding to GB2312, the page displays normally. The reason is that the server Apache sets the global default encoding of the server and adds AddDefaultCharset UTF-8 in httpd.conf. At this time, the server will first send the HTTP header to the browser, and its priority is higher than the encoding declared in the page. Naturally, the browser will recognize it incorrectly. There are two solutions. Administrators should add AddDefaultCharset GB2312 to the configuration file of their own virtual machine to override the global configuration, or configure it in .htaccess in their own directory.

Note after 2006.4.4: Thanks to JunChen for informing: In the HEAD area of the HTML page, This sentence must be written before XXX, otherwise the page will be blank (IE+PHP only)

The above is a summary of the problems I encountered at work some time ago. If there are any mistakes, please correct me