MySQL data type

mysql Data types mainly include ：

• value type
• Date and time type
• String type
• value type

value type

Numeric types mainly include integer 、 Floating point and fixed point types .

Integer types

TINYINT、SMALLINT、MEDIUMINT and INT(INTEGER) and BIGINT.

The specified length of integer type is independent of data value , If the specified length exceeds the value range , It can still be inserted correctly

attribute ：

• ZEROFILL Appoint , Use characters when the number of digits displayed is not enough 0 fill
• UNSIGNED Integer is an unsigned type
• AUTO_INCREMENT Automatic growth , The default from the 1 Began to increase

Floating point type

float 4 Bytes
double 8 Bytes
Size range (M,D) M Represents the number of decimal and integer digits ,D Represents the number of decimal places

Fixed point number type

DECINAL Fixed-point number , Same as floating point numbers (M,D) , But in the mysql In memory, it is represented by characters , So you can save high-precision numbers .

Date time type

Text string type

varchar and char：char It's a fixed length , Insufficient length , Automatic space filling on the right ,varchar It's getting longer .
enum： enumeration , The definition is as follows

create table t(
 e enum('a','b','c')
);

Binary string type

bit、bitary、varbinary、tinyblob、tinyblob、blob、mediumblob、longblob