Shulou(Shulou.com)06/03 Report--

This article introduces the relevant knowledge of "what is the plastic surgery range of 32-bit and 64-bit in PHP and MySql". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

A byte has 8 bits, so the 32-bit int type occupies 32 bits / 8 bits = 4 bytes, and the 64-bit int type occupies 64 bits / 8 bits = 8 bytes.

32-bit, 64-bit unsigned integer maximum:

2 ^ 64-1 = 18446744073709551615

2 ^ 32-1 = 4294967295

32-bit, 64-bit signed integer maximum:

(2 ^ 32) / 2-1 = 2147483647

(2 ^ 64) / 2-1 = 9223372036854775807

Minus 1 is because the integer includes 0.

The value of 64-bit Ubuntu 14.04 PowerPoint inscribed Max is 9223372036854775807, which is the same as the maximum value of signed bigint in MySQL.

The value of 32-bit Ubuntu 14.04 is 2147483647, which is the same as the maximum value of signed int in MySQL.

Echo date ('Y-m-d echo date, PHP_INT_MAX); return 2038-01-19 11:14:07

Echo strtotime ('2038-01-19 1111 14 07'); return 2147483647

Echo strtotime ('2038-01-19 11 / 11 / 14 / 14 / 08'); null is returned under 32 bits

That is, the maximum time () of PHP on 32-bit systems can only return a timestamp of 2038-01-19 11:14:07.

Field type: `posted` int (10) unsigned NOT NULL DEFAULT'0'

On 32-bit MySQL (as well as 64-bit MySQL), inserting a number larger than the maximum of 32-bit unsigned int type 2 ^ 32-1 = 4294967295 will cause an error:

UPDATE `punbb`.`pb _ topics`SET `posted` = '4294967296' WHERE `pb_ topics`.`id` = 1

Warning: # 1264 Out of range value for column 'posted' at row 1

However, MySQL can store 64-bit integers with an 8-byte bigint type.

Data type

LP64

ILP64

LLP64

ILP32

LP32

Char

eight

eight

eight

eight

eight

Short

sixteen

sixteen

sixteen

sixteen

sixteen

_ int32

N/A

thirty-two

N/A

N/A

N/A

Int

thirty-two

sixty-four

thirty-two

thirty-two

sixteen

Long

sixty-four

sixty-four

thirty-two

thirty-two

thirty-two

Long long

N/A

N/A

sixty-four

N/A

N/A

Pointer

sixty-four

sixty-four

sixty-four

thirty-two

thirty-two

This is the end of the content of "what is the plastic surgery range of 32-bit and 64-bit in PHP and MySql". Thank you for reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.