32-bit and 64-bit integer ranges in PHP and MySQL

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

32-bit, 64-bit unsigned integer maximum value:

2^64-1 = 18446744073709551615

2^32-1 = 4294967295

32-bit, 64-bit signed integer maximum value:

(2^32)/2-1 = 2147483647

(2^64)/2-1 = 9223372036854775807

Minus 1 because the integral type includes 0.

The value of 64-bit Ubuntu 14.04,php_int_max is 9223372036854775807, the same as the maximum value of the signed bigint type in MySQL.

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

echo Date (' y-m-d h:i:s ', Php_int_max); return 2038-01-19 11:14:07

echo strtotime (' 2038-01-19 11:14:07 '); Returns 2147483647

echo strtotime (' 2038-01-19 11:14:08 '); Returns null under 32 bits

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

Field type: ' Posted ' int (ten) unsigned not NULL DEFAULT ' 0 '

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

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 a 8-byte bigint type.

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