PHP Mobile Internet Development Notes (6)--mysql Database Basics Review [1]

First, the data type

1. Integral type

Data type	Storage space	Description	Range of values
TINYINT	1 bytes	A very small integer	Signed Value: -128~127 Unsigned value: 0~255
SMALLINT	2 bytes	A smaller integer	Signed Value: -32768~32767 Unsigned value: 0~65535
Mediumnt	3 bytes	A medium-sized integer	Signed Value: -8388608~8388607 Unsigned value: 0~16777215
Int	4 bytes	Standard integer	Signed Value: -2147483648~2147483647 Unsigned value: 0~4294967295
BIGINT	8 bytes	Large integer

2, floating-point type

Data type	Storage space	Description	Range of values
FLOAT	4 bytes	But precision floating-point numbers
DOUBLE	8 bytes	Double-precision floating-point number
DECIMAL (M,D)	Custom	represented as a string

3. String type

td>2^24 bytes

type	storage	description	most Large length
char[(M)]	M byte	fixed length string	M byte
Varc har[(M)]	l+1 byte	variable-length string	M-byte
tinyblog,tingtext	l+1 byte	very small blob and text string	2^8 characters
blog,text	l+2 byte	small blob and text string	2^16-1 bytes
mediumblob,mediumtext	l+3 byte	medium blob and text string
longblob,longtext	l+4 byte	large blob and text string	2^32-1 byte
enum (' Value ', ' value ')	1 or 2 bytes	enumeration: Can be assigned to an enumeration member	65,535 members
Set (' Value ', ' value ')	1,2,3,4 or 8-byte	collection: Can be assigned to multiple collection members	64 members

4. Date and Time type data

Type	Storage space	Description	Maximum length
Date	3 bytes	YYYY-MM-DD format representation	1000-01-01~9999-12-31
Time	3 bytes	HH:MM:SS format represents time values	-838:59:59~838:59:59
Datetime	8 bytes	YYYY-MM-DD HH:MM:SS Format
TIMESTAMP	4 bytes	YYYYMMDDHHMMSS format represents timestamps
Year	1 bytes	Year value in YYYY format	1901~2155

Second, the MySQL database operation

1. Login Database

MySQL parameters

-D,--database=name Open the specified database

--delimiter=name specifying delimiters

-E,--Vertical Vertical display Results

-H,--host=name server name

-H,--HTML provides HTML output

-X,--XML provides XML output

-P,--password[=name] Password

-P,--port=# port number

--prompt=name Setup Prompt

-u,--user=name user name

-v,--version output version information and exit

Mysql-h Server host address-u user name-P user Password

2. Log Out

Exit

Quit

\q

3. Change the password

4. Create selection and view database

Create a database

Select Database

Delete content from the database

PHP Mobile Internet Development Notes (6)--mysql Database Basics Review [1]