Database data types

Data types include integer, floating-point and fixed-point type type, date and time, strings and binary type.

First, the integer type

MySQL's integer types are divided into five kinds: TINYINT, SMALLINT, MEDIUMINT, INT, BIGINT .

Of different integer number of bytes occupied by the type and value ranges are different. As shown below:

 

 

Second, floating-point and fixed-point type

In MySQL, it is stored using decimal floating-point and fixed-point represented.
There are two types of float: single precision floating point type ( FLOAT ), double precision floating point type ( DOUBLE ).

Only one kind of fixed-point type: DECIMAL type.

And the number of bytes occupied FIG following ranges:

Note: the same type of value ranges --DECIMAL DOUBLE type.
   　　- Note that the effective range of DECIMAL type is determined by M and D.
  　　 - where, M is the length of the data, D represents the length after the decimal point.

 

 

Third, the time and date type

The date and time stored in the database, MySQL provides a data type represents dates and times: YEAR, DATE, the TIME, DATETIME, TIMESTAMP

Below lists the number of bytes in the MySQL date and time data corresponding to the type, range, date formats, and a zero value.

Note: If the inserted value is not valid, the system will automatically zero value into the corresponding database.

 

 

Three, string and binary type

To store strings, sound, pictures and data, MySQL binary type and a string is shown below:

Types of	The number of bytes (size)	use
CHAR	0-255 bytes	Fixed length byte character
VARCHAR	0-65535 bytes	Variable length byte character
BLOB	0-65535 bytes	Long text data in binary form
TINYBLOB	0-255 bytes	No more than 255 characters in binary string
MEDIUMBLOB	0-16777215 bytes	Binary text data in the form of medium length
LONGBLOB	0-4294967295 bytes	Great text data in binary form
TEXT	0-65535 bytes	Long text data
TINYTEXT	0-255 bytes	Short text strings
MEDIUMTEXT	0-16777215 bytes	Medium length text data
LONGTEXT	0-4294967295 bytes	Great text data

  Note: similar to CHAR and VARCHAR type, but they save and retrieve different way. Their maximum length and whether trailing spaces are retained, it is also different. In the case conversion is not performed during the storage or retrieval.
   BINARY and VARBINARY type is similar to CHAR and VARCHAR, except that they contain binary strings rather than non-binary strings. That is, they contain byte strings rather than character strings.
   A BLOB is a binary large object, can hold a variable amount of data. There are four BLOB types: TINYBLOB, BLOB, MEDIUMBLOB and LONGBLOB. They differ only in length can accommodate the maximum values.
   TEXT There are four types: TINYTEXT, TEXT, MEDIUMTEXT and LONGTEXT. These types correspond to four kinds of BLOB, the maximum length and have the same storage requirements.