MySQL Value Type

The MySQL Manual provides a review of the MySQL numeric data types, which are summarized as follows:

MySQL supports all standard SQL numeric data types. These types include strict data types: integer, smallint, decimal, numeric, and approximate numeric data types: float, real, and double precision. The keyword Int Is the synonym of integer, and DEC is the synonym of decimal.

1 byte = 8 bits). Each user can only be 0 or 1

1B = 8b

1kb = 1024b

1 MB = 1024kb

1G = 1024 MB

1 TB = 1024 GB

1 Pb = 1024 TB

Type	Bytes	Minimum value	Maximum Value
		(Signed/unsigned)	(Signed/unsigned)
Tinyint	1	-128 (-2 ^ 7)	127 (+ 2 ^ 7)
		0	255 (2 ^ 8)
Smallint	2	-32768 (-2 ^ 15)	32767 (+ 2 ^ 15)
		0	65535 (2 ^ 16)
Mediumint	3	-8388608 (-2 ^ 23)	8388607 (+ 2 ^ 23)
		0	16777215 (2 ^ 24)
Int	4	-2147483648 (-2 ^ 31)	2147483647 (+ 2 ^ 31)
		0	4294967295 (2 ^ 32)
Bigint	8	-9223372036854775808 (-2 ^ 63)	9223372036854775807 (+ 63)
		0	18446744073709551615 (2 ^ 64)

 

Another problem is that when defining a value type, we will specify a width value: int (5), which indicates a realistic width, however, the stored value is not only saved to five digits. This has nothing to do with the length of the value that can be saved. For example: int (5), you can actually store 12345678 without any problems.