PHP connection to MySQL query results showing garbled Chinese characters solution_PHP tutorial

We first assume that the encoding used in the database is UTF-8
At this time, we should first add

, add

In short, the encoding type saved in the web page, the charset=utf-8 of the web page, and the encoding method of the set names utf8 statement executed should be consistent

The following is a good analysis

MySQL "SET NAMES x" character set problem analysis

Recently received training from BBT to build a voting system. The system code was not difficult, but my time was mainly spent studying character sets and encodings. The encoding (character set) issues of the MySQL and Apache systems made me rack my brains and suffer a lot. The solutions to these problems on the Internet are scattered and one-sided. Most of them provide solutions without explaining why. So I will summarize what I have gained in the past few days to avoid latecomers from taking detours again. This article is a little helpful for writing PHP (after reading it, you will know how to make your PHP program display normally on the servers of most space providers), but more help lies in the establishment and settings of the network server.

Let’s talk about MySQL’s character set first. Under Windows, you can modify the

1.# CLIENT SECTION
2.[mysql]
3.default-character-set=utf8
4.# SERVER SECTION
5.[mysqld]
6.default -character-set=utf8

These two fields are used to change the default character set of the database. The first is the client's default character set, and the second is the server's default character set. Suppose we set both to utf8, and then enter "show variebles like "character_set_%";" in the MySQL Command Line Client, you can see the following characters:

character_set_client latin1
character_set_connection latin1
character_set_database utf8
character_set_results latin1
character_set_server utf8
character_set_system utf8

The utf8 in it changes with our settings above. At this time, if we read data from the database through a PHP program using UTF-8, it is likely to be a string of "?????" or other garbled characters. After searching online for a long time, the solution is simple. After connecting to the database and before reading the data, first execute a query "SET NAMES UTF8", which is

1.mysql_query("SET NAMES UTF8");

will display normally (as long as the characters of the information in the database are normal). Why is this happening? What exactly does the query "SET NAMES UTF8" do?

Enter "SET NAMES UTF8;" on the MySQL command line, and then execute "show variebles like "character_set_%";" and find that the values ​​of the variables "character_set_client", "character_set_connection", and "character_set_results" that were originally latin1 have all changed. It's utf8. It turns out that these three variables are causing trouble. Check the manual, the above sentence is equal to:

1.SET character_set_client = utf8;
2.SET character_set_results = utf8;
3.SET character_set_connection = utf8;

Look at the functions of these three variables:

Information input path: client→connection→server;
Information output path: server→connection→results.

In other words, each path needs to change the character set encoding 3 times. Take the garbled output as an example. For the utf8 data in the server, the incoming connection is converted to latin1, the incoming results are converted to latin1, and the utf-8 page converts the results again. If the two character sets are incompatible, such as latin1 and utf8, the conversion process is irreversible and destructive. So it can't be turned back.

But it should be stated here that the effect of "SET NAMES UTF8" is only temporary, and MySQL will return to the default after restarting.

The next step is to talk about the configuration of MySQL on the server. Don't we have to add "SET NAMES UTF8" every time we read and write to the database to ensure that the encoding of data transmission is consistent? Can I configure MySQL so that the three variables default to the character set we want? The manual doesn't say it, and I couldn't find the answer online. Therefore, from a server configuration perspective, there is no way to omit that line of code.

Summary: In order to allow your webpage to be displayed normally on more servers, add "SET NAMES UTF8", even if you have not added it now Sentences can also be accessed normally.