Basic types of MySQL

Recently depressed, the conversion between the underlying type and Java type is unclear, and by the way the information on the Internet lists some types to remind

Mysql

1, integers:

MySQL data type	Meaning (Signed)
tinyint (m)	1 byte range ( -128~127)
smallint (m)	2 byte range ( -32768~32767)
Mediumint (M)	3 byte range ( -8388608~8388607)
Int (m)	4 byte range ( -2147483648~2147483647)
BigInt (M)	8 byte Range (18 +-9.22*10 of the X-square)

2, floating-point type:

MySQL data type	Meaning
Float (m,d)	Single-precision floating-point 8-bit precision (4 bytes) m total number, D decimal place
Double (m,d)	Double-precision floating-point 16-bit precision (8 bytes) m total number, D decimal place

3, fixed point: Decimal (m,d) parameter m represents the total number of digits but less than 65,d less than 30. It is worth noting that floating-point type is the approximate value, fixed-point type actual value

4. Character Type:

MySQL data type	Meaning
CHAR (n)	Fixed length, up to 255 characters
VARCHAR (n)	Fixed length, up to 65,535 characters
Tinytext	Variable length, up to 255 characters
Text	Variable length, up to 65,535 characters
Mediumtext	Variable length, up to 2 of 24 square-1 characters
Longtext	Variable length, up to 2 of 32 square-1 characters

5. Time Type:

MySQL data type	Meaning
CHAR (n)	Fixed length, up to 255 characters
VARCHAR (n)	Fixed length, up to 65,535 characters
Tinytext	Variable length, up to 255 characters
Text	Variable length, up to 65,535 characters
Mediumtext	Variable length, up to 2 of 24 square-1 characters
Longtext	Variable length, up to 2 of 32 square-1 characters

It is important to note that timestamp is updated with other Automatic updates to this data and can be used as an update time

6, binary number: Blob is stored in binary mode, no case, the data can only be read as a whole, blo do not specify a character set.

Basic types of MySQL