MySQL SQL Tutorial

MySQL -
SQL tutorial
Frank Shen
申建忠

MySQL Architecture
Connection Thread Pool
Query Cache
Parser Optimizer
client 1 client 2 client n
Cache&Buffer
Memory
Storage
Engines
MySQL Server
InnoDB MyISAM
File System
Memory
Data Node2
NDB
Data Node
Data Node
Data Node
Network
Data Node
Authentication

MySQL Clients
mysql-執⾏行行Query/DML/DDL的操作介⾯面
mysqladmin-管理理MySQL Server的操作介⾯面
mysqlcheck-檢查MySQL Table的完整性
mysqldump-產⽣生MySQL Table邏輯備份的⼯工具
mysqlimport-匯入⽂文字檔案內容到MySQL Table的⼯工具
mysqlshow-顯⽰示資料庫/表格/欄欄位資訊的⼯工具
mysqlslap-模擬客⼾戶端⼯工作負擔的⼯工具

Connection Layer
Connection Thread Pool
Authentication
Query Cache

Communication
Protocol
Protocol Connection Type Supported OS
TCP/IP Local/Remote ALL
UNIX Socket File Local UNIX
Shared Memory Local Windows
Named Pipes Local Windos

SQL Layer
Parser
Syntax Check
Semantic Check
Query Transformation
Optimizer
Statistics
Optimal Execution Plan

Storage Engines
Disk Base
InnoDB(Default)
MyISAM
Memory
Memory
Network
NDB

Installation Type
http://www.mysql.com/downloads
Binary
RPM
TarBall
Source Compile

RPM Installation
[root@MySQL1 ~]# rpm -i MySQL-client-5.5.30-1.rhel5.x86_64.rpm
[root@MySQL1 ~]# rpm -i MySQL-devel-5.5.30-1.rhel5.x86_64.rpm
[root@MySQL1 ~]# rpm -i MySQL-shared-5.5.30-1.rhel5.x86_64.rpm
[root@MySQL1 ~]# rpm -i MySQL-test-5.5.30-1.rhel5.x86_64.rpm
[root@MySQL1 ~]# /etc/init.d/mysql start
[root@MySQL1 ~]# /usr/bin/mysql_secure_installation

[root@MySQL1 ~}# groupadd mysql
[root@MySQL1 ~}# useradd -g mysql mysql
[root@MySQL1 ~}# passwd mysql
[root@MySQL1 ~]# mv /stage/mysql-5.5.8-linux2.6-x86_64.tar.gz /usr/local
[root@MySQL1 ~]# cd /usr/local
[root@MySQL1 local]# tar -zxvf mysql-5.5.8-linux2.6-x86_64.tar.gz
[root@MySQL1 local]# ln -s /usr/local/mysql-5.5.8-linux2.6-x86_64 mysql
[root@MySQL1 local]# cd mysql
[root@MySQL1 mysql]# chown -R mysql .
[root@MySQL1 mysql]# chgrp -R mysql .
[root@MySQL1 mysql]# scripts/mysql_install_db —user=mysql
[root@MySQL1 mysql]# chown -R root .
[root@MySQL1 mysql]# chown -R mysql data
[root@MySQL1 mysql]# cp support-files/my-medium.cnf /etc/my.cnf
[root@MySQL1 mysql]# bin/mysqld_safe --user=mysql &
[root@MySQL1 mysql]# cp support-files/mysql.server /etc/init.d/mysql

Database/Table
and
Directory/datafile

Create Database
[root@MySQL1 ~]# mysql -uroot -poracle
mysql> show variables like 'datadir';
+---------------+------------------------+
| Variable_name | Value |
+---------------+------------------------+
| datadir | /usr/local/mysql/data/ |
+---------------+------------------------+
1 row in set (0.00 sec)
mysql> create database world_innodb;
Query OK, 1 row affected (0.00 sec)
mysql> use world_innodb;
Database changed
mysql> show tables;
Empty set (0.00 sec)
[root@MySQL1 ~]# ll /usr/local/mysql/data/
drwx------. 2 mysql mysql 4096 2014-06-29 21:49 world_innodb

Database and
Directory
+---------------+------------------------+
+---------------+------------------------+
| datadir | /usr/local/mysql/data/ |
+---------------+------------------------+
mysql> use world_innodb;
Database changed
mysql> show tables;
Empty set (0.00 sec)
[root@MySQL1 ~]# ll /usr/local/mysql/data/
drwx------. 2 mysql mysql 4096 2014-06-29 21:49 world_innodb

Create Table
mysql> show tables;
+------------------------+
| Tables_in_world_innodb |
+------------------------+
| City |
| Country |
| CountryLanguage |
+------------------------+
3 rows in set (0.01 sec)
mysql> show create table City;
+-------+-----------------------------------------------------------------+
| City | CREATE TABLE `City` (
`ID` int(11) NOT NULL AUTO_INCREMENT,
`Name` char(35) NOT NULL DEFAULT '',
`CountryCode` char(3) NOT NULL DEFAULT '',
`District` char(20) NOT NULL DEFAULT '',
`Population` int(11) NOT NULL DEFAULT '0',
PRIMARY KEY (`ID`),
KEY `CountryCode` (`CountryCode`),
CONSTRAINT `city_ibfk_1` FOREIGN KEY (`CountryCode`) REFERENCES `Country`
(`Code`)
) ENGINE=InnoDB AUTO_INCREMENT=4080 DEFAULT CHARSET=latin1 |

mysql> select count(*) from City;
+----------+
| count(*) |
+----------+
| 4079 |
+----------+
mysql> select count(*) from city;
ERROR 1146 (42S02): Table 'world_innodb.city' doesn't exist
mysql> select count(id) from City;
+-----------+
| count(id) |
+-----------+
| 4079 |
+-----------+

Table and Files
[root@MySQL1 ~]# ll /usr/local/mysql/data/world_innodb/
總計 888
-rw-rw----. 1 mysql mysql 8710 2014-06-29 21:49 City.frm
-rw-rw----. 1 mysql mysql 589824 2014-06-29 21:50 City.ibd
-rw-rw----. 1 mysql mysql 9172 2014-06-29 21:49 Country.frm
-rw-rw----. 1 mysql mysql 163840 2014-06-29 21:50 Country.ibd
-rw-rw----. 1 mysql mysql 8702 2014-06-29 21:49 CountryLanguage.frm
-rw-rw----. 1 mysql mysql 114688 2014-06-29 21:50 CountryLanguage.ibd
-rw-rw----. 1 mysql mysql 65 2014-06-29 21:48 db.opt

mysql> select * from t1;
+------+------------+
| id | first_name |
+------+------------+
| 1 | ABC |
| -1 | DEF |
+------+------------+
+------+------------+
| id | first_name |
+------+------------+
| 1 | ABC |
| 0 | DEF |
+------+------------+

INT
Type Storage
Min
(Singed/UnSigned)
Max
(Singed/UnSigned)
TinyINT 1
-128/
0
127/
255
SmallINT 2
-32768/
0
3277/
65535
MediumINT 3
-8388608/
0
8388607/
16777215
INT 4
-214783648/
0
2147483647/
4294967295
BigINT 8
-9223372036854775808/
0
9223372036854775807/
18446744073709551615

DECIMAL
Precision: The number of significant digits
Scale: The number of digits to the right of the
decimal point
DECIMAL(5,2) -> 5=Precision 2=Scale
digit=0,1,2,3,4,5,6,7,8,9
DECIMAL(5,2)的最⼤大值為999.99,最⼩小值為-999.99
DECIMAL(5)=DECIMAL(5,0)
DECIMAL=DECIMAL(10,0)

mysql> create table t3 (id1 int,id2 decimal(5,2));
Query OK, 0 rows affected (0.01 sec)
mysql> insert into t3 values(1234.5,1234.5);
+------+--------+
| id1 | id2 |
+------+--------+
| 1235 | 999.99 | --INT⾃自動4捨5入,DECIMAL超過最⼤大值時,將以最⼤大值儲存
+------+--------+

+------+--------+
| id1 | id2 |
+------+--------+
| 1235 | 999.99 |
| 123 |123.45 |
+------+--------+
+------+--------+
| id1 | id2 |
+------+--------+
| 1235 | 999.99 |
| 123 | 123.45 |
| 12 |12.35 | --DECIMAL也對超過scale限制部分進⾏行行4捨5入
+------+--------+

CHARACTER
CharacterSet-字符集
ascii
latin-1
utf-8
big5
Collation-⼤大⼩小順序
CI(Case InSensitive)

字符集
character-set-
default
預設值
character-set-
client
客⼾端請求字符集
character-set-
results
請求結果字符集
character-set-
server
character-set-
database
character-set-
table

mysql> show collation like 'big5%';
+-----------------+---------+----+---------+----------+---------+
| Collation | Charset | Id | Default | Compiled | Sortlen |
+-----------------+---------+----+---------+----------+---------+
| big5_chinese_ci | big5 | 1 | Yes | Yes | 1 |
| big5_bin | big5 | 84 | | Yes | 1 |
mysql> show collation like 'ascii%';
+------------------+---------+----+---------+----------+---------+
+------------------+---------+----+---------+----------+---------+
| ascii_general_ci | ascii | 11 | Yes | Yes | 1 |
| ascii_bin | ascii | 65 | | Yes | 1 |
+------------------+---------+----+---------+----------+---------+
mysql> show collation like 'utf32%';
+---------------------+---------+-----+---------+----------+---------+
+---------------------+---------+-----+---------+----------+---------+
| utf32_general_ci | utf32 | 60 | Yes | Yes | 1 |
| utf32_bin | utf32 | 61 | | Yes | 1 |
| utf32_unicode_ci | utf32 | 160 | | Yes | 8 |

CHAR
Value CHAR(4)
Storage
Required
VARCHAR(4)
Storage
Required
‘ ’ ‘ ‘ 4 bytes ‘ ‘ 1 bytes
‘ab’ ‘ab ‘ 4 bytes ‘ab’ 3 bytes
‘abcd’ ‘abcd’ 4 bytes ‘abcd’ 5 bytes
‘abcdefgh’ ‘abcd’ 4 bytes ‘abcd’ 5 bytes

DATE
DATE(YYYY-MM-DD)
1000-01-01~9999-12-31
DATETIME(YYYY-MM-DD HH:MI:SS)
1000-01-01 00:00:00~9999-12-31 23:59:59
TIMESTAMP(YYYY-MM-DD HH:MI:SS)
1970-01-01 00:00:01~2038-01-19 03:14:07 UTC
MySQL interprets two-digit year values using these rules:
Year values in the range 00-69 are converted to 2000-2069.
Year values in the range 70-99 are converted to 1970-1999.

MyISAM Features
Storage limits 256TB Transactions No
Locking
Granularrity
Table
MVCC No
Geosptial data
type support
Yes
Geosptial
indexing
support
Yes
B-tree indexes Yes T-tree indexes No Hash indexes No
Full-text
search indexes
Yes
Clustered
indexes
No Data cache No
Index caches Yes Compressed data Yes Encrypted data Yes
Cluster
database
support
No
Replication
support
Yes
Foreign key
support
No
Backup/Point-
in-time
recovery
Yes
Query cache
Support
Yes
Update
statistics for
data dictionary
Yes

+---------------+-----------------------+
+---------------+-----------------------+
| datadir | /usr/local/mysql/data/|
+---------------+-----------------------+
--在datadir⽬目錄下,將⾃自動產⽣生⼀一個⼦子⽬目錄myisam_db
mysql> create database myisam_db;
--建立⼀一個新myisam表格,在相對的資料庫⽬目錄下,⾃自動產⽣生3個file(*.MYD,*.MYI,*.frm)
mysql> create table myisam_db.t1(id int,name char(10))
> engine=myisam; --明確要求此表格為MyISAM形態
mysql> insert into myisam_db.t1
> select id,substr(name,1,10) from world_innodb.City;
Records: 4079 Duplicates: 0 Warnings: 0
[root@MySQL1 ~]# ls -l /usr/local/mysql/data/myisam_db --資料庫
total 84
-rw-rw---- 1 mysql mysql 65 Mar 20 15:48 db.opt
-rw-rw---- 1 mysql mysql 8586 Mar 20 15:48 t1.frm --表格定義
-rw-rw---- 1 mysql mysql 61185 Mar 20 15:48 t1.MYD --表格資料
-rw-rw---- 1 mysql mysql 1024 Mar 20 15:48 t1.MYI --資料索引

InnoDB Features
Storage limits 64TB Transactions Yes Locking
Granularrity
Row
MVCC Yes
Geosptial data
type support
Yes
Geosptial
indexing
support
No
B-tree indexes Yes T-tree indexes Yes Adaptive Hash
indexes
No
Full-text
search indexes
Yes
Clustered
indexes
No Data cache Yes
Index caches Yes Compressed data Yes Encrypted data Yes
Cluster
database
support
No
Replication
support
Yes
Foreign key
support
Yes
Backup/Point-
in-time
recovery
Yes
Query cache
Support
Yes
Update
statistics for
data dictionary
Yes
Multiple buffer
pools
Yes
Performance
Schema
Yes
Automatic Crash
Recovery
Yes

儲存⽅方式
類似Oracle的Index Organized Table
MSSQL的Clustered Table
每個InnoDB的table都需要⼀一個Primary Key,當作索引欄欄位
如何選擇Primary Key
明確指定Primary Key
Unique Constraint+NOT NULL限制的欄欄位
⾃自動產⽣生⼀一個隱藏欄欄位(6 Bytes)當作Primary Key

+---------------+-----------------------+
+---------------+-----------------------+
| datadir | /usr/local/mysql/data/|
+---------------+-----------------------+
--在datadir⽬目錄下,將⾃自動產⽣生⼀一個⼦子⽬目錄innodb_db
mysql> create database innodb_db;
--建立⼀一個新InnoDB表格,在相對的資料庫⽬目錄下,⾃自動產⽣生1個file(*.frm)
--除非設定innodb_file_per_table=TRUE,不然所有Innodb表格的資料都集中儲存在ibdata1
mysql> create table innodb_db.t1(id int,name char(10))
> engine=InnoDB; --明確要求此表格為InnoDB形態
mysql> insert into innodb_db.t1
> select id,substr(name,1,10) from world_innodb.City;
[root@MySQL1 ~]# ls -l /usr/local/mysql/data/innodb_db --資料庫
total 84
-rw-rw---- 1 mysql mysql 65 Mar 20 15:48 db.opt
-rw-rw---- 1 mysql mysql 8586 Mar 20 15:48 t1.frm --表格定義
[root@MySQL1 ~]# ls -l /usr/local/mysql/data/ibdata1
-rw-rw---- 1 mysql mysql 18874368 Mar 20 15:48 /var/lib/mysql/ibdata1 --表格資料

mysql> set @@global.innodb_file_per_table=on;
mysql> create table innodb_db.t2(id int primary key,name varchar(10)) engine=innodb;
mysql> insert into innodb_db.t2 values(1,'A'),(2,'B'),(3,'C');
mysql> select * from innodb_db.t2;
+----+------+
| id | name |
+----+------+
| 1 | A |
| 2 | B |
| 3 | C |
+----+------+
[root@MySQL1 ~]# ls -l /usr/local/mysql/data/ib*
-rw-rw---- 1 mysql mysql 18874368 Mar 20 14:16 /usr/local/mysql/data/ibdata1
-rw-rw---- 1 mysql mysql 5242880 Mar 20 14:16 /usr/local/mysql/data/ib_logfile0
-rw-rw---- 1 mysql mysql 5242880 Mar 18 14:35 /usr/local/mysql/data/ib_logfile1
[root@MySQL1 ~]# ls -l /usr/local/mysql/data/innodb_db/t2.*
-rw-rw---- 1 mysql mysql 8586 Mar 20 14:16 /usr/local/mysql/data/innodb_db/t2.frm
--雖然t2的table data/index獨立儲存在t2.idb裡.但是其使⽤用的undo data還是在共⽤用tablespace裡　
-rw-rw---- 1 mysql mysql 98304 Mar 20 14:16 /usr/local/mysql/data/innodb_db/t2.ibd

Transaction
Atomicity
A transaction’s changes to the state are atomic: either all
happen or none happen. These changes include database
changes, messages, and actions on transducers.
Consistency
A transaction is a correct transformation of the state. The
actions taken as a group do not violate any of the integrity
constraints associated with the state.
Isolation
Even though transactions execute concurrently, it appears to
each transaction T, that others executed either before T or
after T, but not both.
Durability
Once a transaction completes successfully (commits), its
changes to the state survive failures.
source:http://en.wikipedia.org/wiki/Transaction_processing#ACID_criteria

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 |
| MEMORY | YES | Hash based, stored in memory, useful for temporary tables | NO | NO | NO |
| BLACKHOLE | YES | /dev/null storage engine (anything you write to it disappears) | NO | NO | NO |
| MyISAM | YES | MyISAM storage engine | NO | NO | NO |
| CSV | YES | CSV storage engine | 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 |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
mysql> select engine,support
> from information_schema.engines
> where transactions='YES';
+--------+---------+
| engine | support |
+--------+---------+
| InnoDB | DEFAULT |
+--------+---------+
Storage Engines
and Transaction

Transaction Control Language
START TRANSACTION
COMMIT
ROLLBACK
SAVEPOINT savepoint_name
ROLLBACK TO savepoint_name
RELEASE SAVEPOINT savepoint_name

mysql> show variables like 'autocommit';
+---------------+-------+
+---------------+-------+
| autocommit | ON |
+---------------+-------+
mysql> create table world_innodb.t1(a int primary key) engine=innodb;
mysql> create table world_innodb.t2(a int primary key) engine=myisam;
mysql> insert into world_innodb.t1 values(10);
mysql> insert into world_innodb.t2 values(10);
mysql> rollback;
mysql> select * from world_innodb.t1;
+----+
| a |
+----+
| 10 |
+----+
+----+
| a |
+----+
| 10 |
+----+

mysql> set autocommit=0;
mysql> insert into t1 values(20);
mysql> rollback;
Query OK, 0 rows affected, 1 warning (0.01 sec)
mysql> show warnings;
+---------+------+---------------------------------------------------------------+
| Level | Code | Message |
+---------+------+---------------------------------------------------------------+
| Warning | 1196 | Some non-transactional changed tables couldn't be rolled back |
+---------+------+---------------------------------------------------------------+
+----+
| a |
+----+
| 10 |
+----+
+----+
| a |
+----+
| 10 |
| 20 |
+----+

mysql> set autocommit=1;
mysql> start transaction;
+----+
| a |
+----+
| 10 |
| 20 |
| 30 |
+----+
mysql> rollback;
+----+
| a |
+----+
| 10 |
+----+

Isolation Problems
Dirty read
A dirty read (aka uncommitted dependency) occurs when a
transaction is allowed to read data from a row that has been
modified by another running transaction and not yet
committed.
Non-Repeatable read
A non-repeatable read occurs, when during the course of a
transaction, a row is retrieved twice and the values within
the row differ between reads.
Phantom read
A phantom read occurs when, in the course of a transaction,
two identical queries are executed, and the collection of
rows returned by the second query is different from the
first.
source:http://en.wikipedia.org/wiki/Isolation_(database_systems)

Isolation Mode
Read UnCommitted
Dirty Read
Read Committed
Non-Repeatable Read/Phantom Read
Repeatable Read
Non-Repeatable Read/Phantom Read(InnoDB沒問題)
Serializable
Non-Repeatable Read/Phantom Read

mysql> select @@global.tx_isolation,@@session.tx_isolation;
+-----------------------+------------------------+
| @@global.tx_isolation | @@session.tx_isolation |
+-----------------------+------------------------+
| REPEATABLE-READ | REPEATABLE-READ |
+-----------------------+------------------------+
mysql> set session transaction isolation level read committed;
mysql> select @@global.tx_isolation,@@session.tx_isolation;
+-----------------------+------------------------+
| @@global.tx_isolation | @@session.tx_isolation |
+-----------------------+------------------------+
| REPEATABLE-READ | READ-COMMITTED |
+-----------------------+------------------------+

Lock
Get Lock
Explicit
TABLE Level
mysql> LOCK TABLES t1 READ;
mysql> LOCK TABLES t2 WRITE;
ROW Level
mysql> SELECT * FROM City WHERE id=123 LOCK IN SHARE MODE;
mysql> SELECT * FROM City WHERE id=123 FOR UPDATE;
Implicit
Lock table or row(InnoDB) based on the SQL commands issued and
Storage Engine being used.
MODE
Shared
Exclusive

Implicit Locks
InnoDB MyISAM
SELECT No Lock
Table-level
Shared Lock
UPDAT/DELETE
Row-level
Exclusive Lock
Table-level
Exclusive lock
ALTER TABLE
Table-level
Shared lock
Table-level
Shared lock

Interaction of Table
Locking and
Transactions
LOCK TABLES
is not transaction-safe and implicitly commits any
active transaction before attempting to lock the tables.
UNLOCK TABLES
implicitly commits any active transaction, but only if
LOCK TABLES has been used to acquire table locks.
FLUSH TABLES WITH READ LOCK
acquires a global read lock and not table locks, so it
is not subject to the same behavior as LOCK TABLES and
UNLOCK TABLES with respect to table locking and implicit
commits.

mysql> LOCK TABLES t1 READ;
+----+
| a |
+----+
| 10 |
+----+
ERROR 1100 (HY000): Table 't2' was not locked with LOCK TABLES
mysql> LOCK TABLES t2 WRITE;
+----+
| a |
+----+
| 10 |
| 20 |
| 30 |
+----+
mysql> UNLOCK TABLES;

mysql> flush table t2,t1 with read lock;
+----+
| a |
+----+
| 10 |
+----+
+----+
| a |
+----+
| 10 |
| 20 |
| 30 |
+----+
mysql> unlock tables;
mysql> flush tables t2 with read lock;
ERROR 1100 (HY000): Table 't1' was not locked with LOCK TABLES
mysql> flush tables t1 with read lock;
ERROR 1192 (HY000): Can't execute the given command because you have active
locked tables or an active transaction
mysql> lock tables t1 read;
+----+
| a |
+----+
| 10 |
+----+

3A
Authentication
Who are you ?
Access Control,Stage 1
implement on Connection Layer
Authorization
What can you do ?
Access Control,Stage 2
implement on Connection Layer
Audit
What was you done ?

mysql> desc mysql.user;
+------------------------+-----------------------------------+------+-----+---------+-------+
+------------------------+-----------------------------------+------+-----+---------+-------+
| Host | char(60) | NO | PRI | | |
| User | char(16) | NO | PRI | | |
| Password | char(41) | NO | | | |
| Select_priv | enum('N','Y') | NO | | N | |
| Insert_priv | enum('N','Y') | NO | | N | |
| Update_priv | enum('N','Y') | NO | | N | |
| Delete_priv | enum('N','Y') | NO | | N | |
| Create_priv | enum('N','Y') | NO | | N | |
| Drop_priv | enum('N','Y') | NO | | N | |
| Reload_priv | enum('N','Y') | NO | | N | |
| Shutdown_priv | enum('N','Y') | NO | | N | |
| Process_priv | enum('N','Y') | NO | | N | |
| File_priv | enum('N','Y') | NO | | N | |
| Grant_priv | enum('N','Y') | NO | | N | |
| References_priv | enum('N','Y') | NO | | N | |
| Index_priv | enum('N','Y') | NO | | N | |
| Alter_priv | enum('N','Y') | NO | | N | |
| Show_db_priv | enum('N','Y') | NO | | N | |
| Super_priv | enum('N','Y') | NO | | N | |
| Create_tmp_table_priv | enum('N','Y') | NO | | N | |
| Lock_tables_priv | enum('N','Y') | NO | | N | |
| Execute_priv | enum('N','Y') | NO | | N | |
| Repl_slave_priv | enum('N','Y') | NO | | N | |
| Repl_client_priv | enum('N','Y') | NO | | N | |
| Create_view_priv | enum('N','Y') | NO | | N | |
| Show_view_priv | enum('N','Y') | NO | | N | |
| Create_routine_priv | enum('N','Y') | NO | | N | |
| Alter_routine_priv | enum('N','Y') | NO | | N | |
| Create_user_priv | enum('N','Y') | NO | | N | |
| Event_priv | enum('N','Y') | NO | | N | |
| Trigger_priv | enum('N','Y') | NO | | N | |
| Create_tablespace_priv | enum('N','Y') | NO | | N | |
| ssl_type | enum('','ANY','X509','SPECIFIED') | NO | | | |
| ssl_cipher | blob | NO | | NULL | |
| x509_issuer | blob | NO | | NULL | |
| x509_subject | blob | NO | | NULL | |
| max_questions | int(11) unsigned | NO | | 0 | |
| max_updates | int(11) unsigned | NO | | 0 | |
| max_connections | int(11) unsigned | NO | | 0 | |
| max_user_connections | int(11) unsigned | NO | | 0 | |
| plugin | char(64) | YES | | | |
| authentication_string | text | YES | | NULL | |
+------------------------+-----------------------------------+------+-----+---------+-------+

mysql> create user 'linda'@'192.168.56.1' identified by 'mysql';
+-------+--------------+-------------------------------------------+
+-------+--------------+-------------------------------------------+
| frank | % | |
| linda | 192.168.56.1 | *E74858DB86EBA20BC33D0AECAE8A8108C56B17FA |
+-------+--------------+-------------------------------------------+
--linda只能由主機位置192.168.56.1使⽤用密碼myql登入此MySQL

With InnoDB tables, OPTIMIZE TABLE re-creates the table.
CHECK TABLE options that are applicable to MyISAM only:
QUICK: Do not scan the rows to check for incorrect links.
FAST: Check only tables that were not closed properly.
CHANGED: Check only tables that changed since the last check or
were not closed properly.
MEDIUM: Scan rows to verify that deleted links are valid.
EXTENDED: Do a full key lookup for all keys for each row.
Some mysqlcheck maintenance options:
--analyze: Perform an ANALYZE TABLE.
--check: Perform a CHECK TABLE (default).
--optimize: Perform an OPTIMIZE TABLE.
--repair: Perform a REPAIR TABLE

mysql> check table world_innodb.City;
+-------------------+-------+----------+----------+
| Table | Op | Msg_type | Msg_text |
+-------------------+-------+----------+----------+
| world_innodb.City | check | status | OK |
+-------------------+-------+----------+----------+
mysql> check table world_myisam.City;
+-------------------+-------+----------+----------+
+-------------------+-------+----------+----------+
| world_myisam.City | check | status | OK |
+-------------------+-------+----------+----------+
mysql> analyze table world_myisam.City; --此動作將被記錄在Binary Log裡
+-------------------+---------+----------+-----------------------------+
+-------------------+---------+----------+-----------------------------+
| world_myisam.City | analyze | status | Table is already up to date |
+-------------------+---------+----------+-----------------------------+
ANALYZE TABLE requires SELECT and INSERT privileges, only (LOCK TABLES is not
needed).

mysql> analyze no_write_to_binlog table world_myisam.City;
+-------------------+---------+----------+-----------------------------+
+-------------------+---------+----------+-----------------------------+
| world_myisam.City | analyze | status | Table is already up to date |
+-------------------+---------+----------+-----------------------------+
mysql> analyze local table world_innodb.City;
+-------------------+---------+----------+----------+
+-------------------+---------+----------+----------+
| world_innodb.City | analyze | status | OK |
+-------------------+---------+----------+----------+
analyze [local|no_write_to_binlog] table xxx.xx
--可以不要將analyze操作紀錄在binary log,所以不會導致slave database也進⾏行行相同的操作
mysql> checksum table world_myisam.City;
+-------------------+------------+
| Table | Checksum |
+-------------------+------------+
| world_myisam.City | 2011482258 |
+-------------------+------------+

mysql> repair table world_myisam.City;
+-------------------+--------+----------+----------+
+-------------------+--------+----------+----------+
| world_myisam.City | repair | status | OK |
+-------------------+--------+----------+----------+
mysql> repair table world_innodb.City;
+-------------------+--------+----------+---------------------------------------------------------+
+-------------------+--------+----------+---------------------------------------------------------+
| world_innodb.City | repair | note | The storage engine for the table doesn't support repair |
+-------------------+--------+----------+---------------------------------------------------------+
mysql> optimize table world_myisam.City;
+-------------------+----------+----------+----------+
+-------------------+----------+----------+----------+
| world_myisam.City | optimize | status | OK |
+-------------------+----------+----------+----------+
mysql> optimize table world_innodb.City;
+-------------------+----------+----------+-------------------------------------------------------------------+
+-------------------+----------+----------+-------------------------------------------------------------------+
| world_innodb.City | optimize | note | Table does not support optimize, doing recreate + analyze instead |
| world_innodb.City | optimize | status | OK |
+-------------------+----------+----------+-------------------------------------------------------------------+

Exportmysql> create database demodb;
mysql> use demodb;
Database changed
mysql> create table t1(a int primary key,b varchar(10));
mysql> insert into t1 values (1,'A'),(2,'B'),(3,'C'),(4,'D');
+---+------+
| a | b |
+---+------+
| 1 | A |
| 2 | B |
| 3 | C |
| 4 | D |
+---+------+
mysql> flush tables with read lock; --只允許讀取,不允許異異動
[root@MySQL1 ~]# mysqldump --master-data demodb -uroot -poracle > demodb.sql
mysql> unlock tables;

Import
[root@MySQL ~]# mysql -uroot -poracle
mysql> create database new_demodb;
mysql> use new_demodb;
Database changed
mysql> source /root/demodb.sql
mysql> select * from new_demodb.t1;
+---+------+
| a | b |
+---+------+
| 1 | A |
| 2 | B |
| 3 | C |
| 4 | D |
+---+------+

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