Basic mysql operations,
I. Basic operations
After connecting to Mysql, add a semicolon (;) to the end of an SQL statement.
# When creating data, you can add a back quotation mark (a key on the TAB key) before and after the database name so that you can create a database with a keyword. Otherwise, an error is returned.
Mysql> create database customer; Query OK, 1 row affected (0.00 sec)
mysql> select version();+-----------+| version() |+-----------+| 5.6.38 |+-----------+1 row in set (0.00 sec)
mysql> select database();+------------+| database() |+------------+| NULL |+------------+1 row in set (0.00 sec)
- View the current logon Username
mysql> select user();+----------------+| user() |+----------------+| root@localhost |+----------------+1 row in set (0.00 sec)
- View the current logon Username
mysql> select current_user();+----------------+| current_user() |+----------------+| root@localhost |+----------------+1 row in set (0.00 sec)
- View current date and time
mysql> select curtime(),curdate(),now();+-----------+------------+---------------------+| curtime() | curdate() | now() |+-----------+------------+---------------------+| 15:43:50 | 2018-01-15 | 2018-01-15 15:43:50 |+-----------+------------+---------------------+1 row in set (0.00 sec)
- View the number of databases
mysql> show databases;+--------------------+| Database |+--------------------+| information_schema || mysql || performance_schema || test |+--------------------+4 rows in set (0.01 sec)
- Deletes a specified database.
Drop database Name
- Switch a database to the current database
Use Database Name
mysql> use testDatabase changedmysql> select database();+------------+| database() |+------------+| test |+------------+1 row in set (0.00 sec)
mysql> show variables like 'char%';+--------------------------+--------------------------+| Variable_name | Value |+--------------------------+--------------------------+| character_set_client | gbk || character_set_connection | gbk || character_set_database | latin1 || character_set_filesystem | binary || character_set_results | gbk || character_set_server | latin1 || character_set_system | utf8 || character_sets_dir | c:\mysql\share\charsets\ |+--------------------------+--------------------------+8 rows in set (0.00 sec)
- Set the character set of the connection server and the current client
mysql> set names utf8;Query OK, 0 rows affected (0.00 sec)
- View the character sets supported by the current service
mysql> show charset;+----------+-----------------------------+---------------------+--------+| Charset | Description | Default collation | Maxlen |+----------+-----------------------------+---------------------+--------+| big5 | Big5 Traditional Chinese | big5_chinese_ci | 2 || dec8 | DEC West European | dec8_swedish_ci | 1 || cp850 | DOS West European | cp850_general_ci | 1 || hp8 | HP West European | hp8_english_ci | 1 || koi8r | KOI8-R Relcom Russian | koi8r_general_ci | 1 || latin1 | cp1252 West European | latin1_swedish_ci | 1 || latin2 | ISO 8859-2 Central European | latin2_general_ci | 1 || swe7 | 7bit Swedish | swe7_swedish_ci | 1 || ascii | US ASCII | ascii_general_ci | 1 || ujis | EUC-JP Japanese | ujis_japanese_ci | 3 || sjis | Shift-JIS Japanese | sjis_japanese_ci | 2 || hebrew | ISO 8859-8 Hebrew | hebrew_general_ci | 1 || tis620 | TIS620 Thai | tis620_thai_ci | 1 || euckr | EUC-KR Korean | euckr_korean_ci | 2 || koi8u | KOI8-U Ukrainian | koi8u_general_ci | 1 || gb2312 | GB2312 Simplified Chinese | gb2312_chinese_ci | 2 || greek | ISO 8859-7 Greek | greek_general_ci | 1 || cp1250 | Windows Central European | cp1250_general_ci | 1 || gbk | GBK Simplified Chinese | gbk_chinese_ci | 2 || latin5 | ISO 8859-9 Turkish | latin5_turkish_ci | 1 || armscii8 | ARMSCII-8 Armenian | armscii8_general_ci | 1 || utf8 | UTF-8 Unicode | utf8_general_ci | 3 || ucs2 | UCS-2 Unicode | ucs2_general_ci | 2 || cp866 | DOS Russian | cp866_general_ci | 1 || keybcs2 | DOS Kamenicky Czech-Slovak | keybcs2_general_ci | 1 || macce | Mac Central European | macce_general_ci | 1 || macroman | Mac West European | macroman_general_ci | 1 || cp852 | DOS Central European | cp852_general_ci | 1 || latin7 | ISO 8859-13 Baltic | latin7_general_ci | 1 || utf8mb4 | UTF-8 Unicode | utf8mb4_general_ci | 4 || cp1251 | Windows Cyrillic | cp1251_general_ci | 1 || utf16 | UTF-16 Unicode | utf16_general_ci | 4 || utf16le | UTF-16LE Unicode | utf16le_general_ci | 4 || cp1256 | Windows Arabic | cp1256_general_ci | 1 || cp1257 | Windows Baltic | cp1257_general_ci | 1 || utf32 | UTF-32 Unicode | utf32_general_ci | 4 || binary | Binary pseudo charset | binary | 1 || geostd8 | GEOSTD8 Georgian | geostd8_general_ci | 1 || cp932 | SJIS for Windows Japanese | cp932_japanese_ci | 2 || eucjpms | UJIS for Windows Japanese | eucjpms_japanese_ci | 3 |+----------+-----------------------------+---------------------+--------+40 rows in set (0.02 sec)
mysql> show engines;+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+| Engine | Support | Comment | Transactions | XA | Savepoints |+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+| FEDERATED | NO | Federated MySQL storage engine | NULL | NULL | NULL || MRG_MYISAM | YES | Collection of identical MyISAM tables | NO | NO | NO || MyISAM | YES | MyISAM storage engine | NO | NO | NO || BLACKHOLE | YES | /dev/null storage engine (anything you write to it disappears) | NO | NO | NO || CSV | YES | CSV storage engine | NO | NO | NO || MEMORY | YES | Hash based, stored in memory, useful for temporary tables | NO | NO | NO || ARCHIVE | YES | Archive storage engine | NO | NO | NO || InnoDB | DEFAULT | Supports transactions, row-level locking, and foreign keys | YES | YES | YES || PERFORMANCE_SCHEMA | YES | Performance Schema | NO | NO | NO |+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+9 rows in set (0.01 sec)
- Modify the character set of a Database
mysql> alter database `db` character set utf8;Query OK, 1 row affected (0.00 sec)