Data classes and MySQL models

Show Engient;

Show table status like ' user ' \g

Client: Mysql,mysqladmin, mysqldump, Mysqlimport, Mysqlcheck

Servers: mysqld, Mysqld_safe, Mysqld_multi

My.cnf

/ETC/MY.CNF--/ETC/MYSQL/MY.CNF-$MYSQL _home/my.cnf----default-extra-file=/path/to/somefile--~/ . my.cnf

[[email protected] ~]# mysqld--help--verbose View information about various MySQL commands

DataDir =/mydata/data

Hostname.err: Error Log

1. Previous server not shutdown

2. Data initialization failed

3. Data Directory Location error

4. Data Catalog Permissions Issues

Data type:
Numeric type

Exact values

Int

Decimal

Approximate values

Float

Double

Real

Character type

Fixed length: CHAR (#), BINARY

Variable length: VARCHAR (#), VARBINARY

Text,blob

ENUM SET

Date-Time Type

Date, time, datetime, timestamp

Domain properties, modifier:

Data type:

1. Type of value deposited

2. Occupy the storage space

3. Fixed length or length of change

4. How to compare and sort

5. Is it possible to index

Numeric type:

Plastic:

TINYINT 1 bytes

SMALLINT 2 bytes

Mediumint 3 bytes

INT 4 bytes

BIGINT 8 bytes

Fixed-point number decimal

Single-precision float float 4 bytes

Double-precision floating-point dowble 8 bytes

Bitwise STORAGE Bit

String type:

CHAR fixed length

VARCHAR variable length case insensitive

BINARY fixed length

VARBINARY variable length case insensitive

Tinyblob Case Sensitive

BLOB Standard

Mediumblob Intermediate

Longblob Long

Tinytext Case insensitive

TEXT

Mediumtext

Longtext

enum Enum type

Set Set

This article from "Operation and maintenance Growth Road" blog, declined reprint!

Data classes and MySQL models