Shulou(Shulou.com)06/01 Report--

1.select count () from mysql.user;// finds the number of rows in the user table of the mysql library

Mysql > select count () from mysql.user;//count () will be fast in myisam, innoDB engine will be very slow (will not count rows, very time-consuming), and all operations will be reduced as much as possible

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| | count (*) |

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| | 8 |

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2.select from mysql.db

Mysql > select from mysql.db\ G; / / find all the contents of the db table of the mysql library

1. Row

Host:%

Db: test

User:

Select_priv: Y

Insert_priv: Y

Update_priv: Y

3.select db from mysql.db

Select db from mysql.db; / / find fields whose db table of the mysql library is db

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| | db |

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| | test |

| | test_% |

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4.select db,user from mysql.db

Select db,user from mysql.db; / / can query two fields

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| | db | user |

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| | test |

| | test_% |

| | db1 | user2 |

| | discuz | discuz |

| | db1 | user1 |

| | db1 | user3 |

| | discuz | discuz |

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7 rows in set (0.00 sec)

5.select from mysql.db where host like '192.168% matching; / / like fuzzy matching

Mysql > select from mysql.db where host like '192.168%'\ G

2. Row

Host: 192.168.211.1%

Db: discuz

User: discuz

Select_priv: Y

Insert_priv: Y

Update_priv: Y

Delete_priv: Y

6.insert into db1.t1 values (1, 'abc'); / / insert

Mysql > insert db1.t1 values (1)

Query OK, 1 row affected (0.11 sec)

Mysql > select * from db1.t1

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| | id | name |

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| | 1 | abc |

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1 row in set (0.01 sec)

Desc db1.t1; / / View the structure of the table

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| | Field | Type | Null | Key | Default | Extra | |

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| | id | int (4) | YES | | NULL |

| | name | char (40) | YES | | NULL |

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2 rows in set (0.00 sec)

Mysql > insert into db1.t1 values (1); / / insert statements. You can also make some restrictions, the same value, different id, the same number is reported to conflict

Query OK, 1 row affected (0.21 sec)

Select * from db1.t1

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| | id | name |

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| | 1 | abc |

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7.update db1.t1 set name='aaa' where id=1;// changed the name of the T1 table id of the db1 library to aaa

Mysql > select from db1.t1

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| | id | name |

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| | 1 | abc |

| | 1 | lsx |

| | 3 | lshx |

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3 rows in set (0.01sec)

Mysql > update db1.t1 set name='lsx01' where id=1

Query OK, 2 rows affected (0.55 sec)

Rows matched: 2 Changed: 2 Warnings: 0

Mysql > select from db1.t1

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| | id | name |

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| | 1 | lsx01 |

| | 1 | lsx01 |

8.delete from db1.t1 where id=6;// deletes the row with id 6 in the T1 table of the db library

Mysql > select from db1.t1

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| | id | name |

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| | 1 | abc |

| | 111 | lsx |

| | 111 | lshx |

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3 rows in set (0.00 sec)

Mysql > delete from db1.t1 where id=111

Query OK, 2 rows affected (0.28 sec)

Mysql > select from db1.t1

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| | id | name |

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| | 1 | abc |

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1 row in set (0.00 sec)

9.truncate table db1.t1;// clears the contents of the T1 table. Keep the table structure

The structure and contents of the 10.drop table db1.t1;// library are all emptied.

11.drop database db1.t1;// deletes the content and structure of the T1 table

12.drop database db1;// deletes the database

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