MySQL Several FAQs summary

MySQL Several FAQs summary

One.

1. command to clear the screen under MySQL

\! Clear;ctrl+shift+l;ctrl+l

Commands for clear screen under Linux

Clear; Ctrl+l; Shift+ctrl+l

Two. Four ways to view MySQL version

1: Under the terminal: Mysql-v. Here is the code snippet:

[Email protected] ~]$ mysql-v
MySQL Ver 14.7 distrib 4.1.10a, for Redhat-linux-gnu (i686)

2::mysql> status in MySQL;
Here is the code snippet:
mysql> status;
--------------
MySQL Ver 14.7 distrib 4.1.10a, for Redhat-linux-gnu (i686)
Connection id:416
Ssl:not in use
Current Pager:stdout
Using outfile: '
Using delimiter:;
Server Version:3.23.56-log
Protocol version:10
Connection:localhost via UNIX socket
Client characterset:latin1
Server characterset:latin1
UNIX Sockets:/tmp/mysql_3311.sock
Uptime:62 Days Hours min sec
Threads:1 questions:584402560 Slow queries:424 opens:59664208 Flush tables:1 Open tables:64 queries per second avg: 107.551

3: Find in Help
Here is the code snippet:
[[email protected] ~]$ MySQL--help | grep distrib
MySQL Ver 14.7 distrib 4.1.10a, for Redhat-linux-gnu (i686)

4: Using MySQL's functions
Here is the code snippet:
Mysql> select version ();
+-------------+
| Version () |
+-------------+
| 3.23.56-log |
+-------------+
1 row in Set (0.00 sec)

Three.

MySQL Character set

a). Display Character Set
Mysqladmin-uroot-proot Variables | grep character or

Show variables like '%char% ' in MySQL command mode;

| character_set_client | Latin1 |
| character_set_connection | Latin1 |
| Character_set_database | Latin1 |
| Character_set_results | Latin1 |
| Character_set_server | Latin1 |
| Character_set_system | UTF8 |
| Character_sets_dir | /usr/local/share/mysql/charsets/|

Database default using Latin1 (ISO-8859)


II). Configuring the Character Set

1. Configuring the character set when building the library

Create DATABASE testxxx default Charset=utf8

3. Configuring the character set when building a table

CREATE TABLE ' t_agent ' (
' ID ' smallint (5) Not NULL
) DEFAULT Charset=utf8;

4. Modifying the character Set

Windows platform
The MySQL configuration file under Windows is My.ini, generally in C:\windows\my.ini or c:\winnt\my.ini can be added directly in this file
DEFAULT-CHARACTER-SET=GBK #或gb2312, Big5,utf8
Then restart MySQL
Service MySQL Restart
Or
/etc/init.d/mysql restart
or restart it in another way, it takes effect.

Edit UNIX Platform
The MySQL configuration file under Linux is my.cnf, generally/etc/my.cnf, if not found can be found with the Find command:
Find/-iname MY.CNF
In this file, add
DEFAULT-CHARACTER-SET=GBK #或gb2312, Big5,utf8

Then restart MySQL

Note: If the startup error is as follows:

/usr/libexec/mysqld:unknown variable ' Default_character_set=utf8 '

You can replace Default-character-set=utf8 with Character_set_server=utf8 to solve this problem,

Another way to modify the default character set:

(2) Another way to modify the MySQL default character set is to use the MySQL command

mysql> SET character_set_client = UTF8;
mysql> SET character_set_connection = UTF8;
mysql> SET character_set_database = UTF8;
mysql> SET character_set_results = UTF8;
mysql> SET character_set_server = UTF8;

mysql> SET collation_connection = UTF8;
mysql> SET collation_database = UTF8;
mysql> SET collation_server = UTF8;

In general, even if you set the table MySQL default character set is UTF8 and send the query through UTF-8 encoding, you will find that the database is still garbled. The problem is on the connection connection layer. The workaround is to execute the following sentence before sending the query:

SET NAMES ' UTF8 ';

It is equivalent to the following three-sentence instruction:

SET character_set_client = UTF8;
SET character_set_results = UTF8;
SET character_set_connection = UTF8;

This article is from the "Technical Achievement Dream" blog, please be sure to keep this source http://pizibaidu.blog.51cto.com/1361909/1618728

MySQL Several FAQs summary