In the process of using MySQL database, we often encounter garbled code problems. For this problem, we can solve it by setting the default character set when connecting to mysql. This article will introduce how to set the connection character set of MySQL to avoid garbled characters when using the database.
1. Introduction to character sets
Character set is a very important concept when using MySQL database. The so-called character set (Charset) refers to the encoding scheme used to represent characters. In computers, characters are stored in binary form. In order to display and process characters correctly, we need to specify a scheme that matches characters with binary codes. This is the role of character sets.
The default character set of MySQL is latin1, and the character set we generally use is utf8. latin1 only supports single-byte characters, while utf8 supports multi-byte characters, including non-ASCII characters such as Chinese. Therefore, if we need to store non-ASCII characters such as Chinese in the MySQL database, we need to use the utf8 character set.
2. Connection character set setting
In MySQL, there are two connection character sets that need to be set: client connection character set and server connection character set:
1. Client connection character set
The client connection character set is used to tell the MySQL client what encoding method it should use to connect to the server. Before connecting to the server, the MySQL client needs to encode the input characters according to this character set before communicating with the server.
We can set the client connection character set by adding the following content to the configuration file my.cnf:
[client]
default-character-set=utf8
After this setting, the utf8 character set will be used every time you use the command line tool to connect to the MySQL server.
In addition, if you don’t want to set it in my.cnf, you can also specify the character set when connecting:
mysql -uusername -p -hhostname --default-character-set=utf8
2. Server connection character set
The server connection character set is the character set when the server receives the client request, which determines the character set type input by the server when executing the statement. We can set the server connection character set by adding the following to the my.cnf configuration file:
[mysqld]
character-set-server=utf8
or in Add the following content to the MySQL configuration file:
[client]
default-character-set=utf8
[mysqld]
default-character-set =utf8
After setting this, the utf8 character set will be used by default every time the database is started.
After modifying the my.cnf file, you need to restart the database server for the configuration to take effect.
3. Other matters needing attention
1. The character set must be specified consistently
It should be noted that during the use of the MySQL database, whether on the client or On the server side, you need to specify the same character set encoding. Otherwise, garbled characters will appear when reading and writing data.
2. Data table character set setting
After the character sets of the client and server connections are both set to utf8, you want the data in the database to correctly store Chinese and other non-ASCII characters. , you also need to set the character set of each table. You can set the character set of the table through the following statement:
ALTER TABLE tablename CONVERT TO CHARACTER SET utf8;
Or specify the character set when creating the table:
create table tablename(
columnname datatype character set utf8
);
In short, no matter what stage of setting, you need to ensure that the settings of all character sets are consistent in order to be correct to perform data operations.
4. Summary
In order to avoid garbled characters when using MySQL, we need to set the correct character set encoding when connecting to MySQL. When setting up, you need to pay attention to setting the character set of the client and server connections, and ensure that all tables use the same character set. By correctly setting the character set, we can avoid many garbled characters and better use the MySQL database.
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