INET_ATON(expr)

MySQL :: MySQL 8.0 Reference Manual :: 12.24 Miscellaneous Functions https://dev.mysql.com/doc/refman/8.0/en/miscellaneous-functions.html#function_inet-aton

• INET_ATON(expr)

  Given the dotted-quad representation of an IPv4 network address as a string, returns an integer that represents the numeric value of the address in network byte order (big endian). INET_ATON() returns NULL if it does not understand its argument.

  mysql> SELECT INET_ATON('10.0.5.9');
          -> 167773449

  For this example, the return value is calculated as 10×256³ + 0×256² + 5×256 + 9.

  INET_ATON() may or may not return a non-NULL result for short-form IP addresses (such as '127.1' as a representation of '127.0.0.1'). Because of this, INET_ATON()a should not be used for such addresses.

  Note

  To store values generated by INET_ATON(), use an INT UNSIGNED column rather than INT, which is signed. If you use a signed column, values corresponding to IP addresses for which the first octet is greater than 127 cannot be stored correctly. See Section 11.1.7, “Out-of-Range and Overflow Handling”.

• INET_NTOA(expr)

  Given a numeric IPv4 network address in network byte order, returns the dotted-quad string representation of the address as a string in the connection character set. INET_NTOA() returns NULL if it does not understand its argument.

  mysql> SELECT INET_NTOA(167773449);
          -> '10.0.5.9'

• INET_ATON(expr)

  Given the dotted-quad representation of an IPv4 network address as a string, returns an integer that represents the numeric value of the address in network byte order (big endian). INET_ATON() returns NULL if it does not understand its argument.

  mysql> SELECT INET_ATON('10.0.5.9');
          -> 167773449

  For this example, the return value is calculated as 10×256³ + 0×256² + 5×256 + 9.

  INET_ATON() may or may not return a non-NULL result for short-form IP addresses (such as '127.1' as a representation of '127.0.0.1'). Because of this, INET_ATON()a should not be used for such addresses.

  Note

  To store values generated by INET_ATON(), use an INT UNSIGNED column rather than INT, which is signed. If you use a signed column, values corresponding to IP addresses for which the first octet is greater than 127 cannot be stored correctly. See Section 11.1.7, “Out-of-Range and Overflow Handling”.

• INET_NTOA(expr)

  Given a numeric IPv4 network address in network byte order, returns the dotted-quad string representation of the address as a string in the connection character set. INET_NTOA() returns NULL if it does not understand its argument.

  mysql> SELECT INET_NTOA(167773449);
          -> '10.0.5.9'

标签：network,expr,returns,ATON,address,INET,addresses
来源： https://www.cnblogs.com/rsapaper/p/15402642.html