PostgreSQL 8.1.23 Documentation | ||||
---|---|---|---|---|
Prev | Fast Backward | Chapter 9. Functions and Operators | Fast Forward | Next |
Table 9-31 shows the operators available for the cidr and inet types. The operators <<, <<=, >>, and >>= test for subnet inclusion. They consider only the network parts of the two addresses, ignoring any host part, and determine whether one network part is identical to or a subnet of the other.
Table 9-31. cidr and inet Operators
Operator | Description | Example |
---|---|---|
< | is less than | inet '192.168.1.5' < inet '192.168.1.6' |
<= | is less than or equal | inet '192.168.1.5' <= inet '192.168.1.5' |
= | equals | inet '192.168.1.5' = inet '192.168.1.5' |
>= | is greater or equal | inet '192.168.1.5' >= inet '192.168.1.5' |
> | is greater than | inet '192.168.1.5' > inet '192.168.1.4' |
<> | is not equal | inet '192.168.1.5' <> inet '192.168.1.4' |
<< | is contained within | inet '192.168.1.5' << inet '192.168.1/24' |
<<= | is contained within or equals | inet '192.168.1/24' <<= inet '192.168.1/24' |
>> | contains | inet '192.168.1/24' >> inet '192.168.1.5' |
>>= | contains or equals | inet '192.168.1/24' >>= inet '192.168.1/24' |
Table
9-32 shows the functions available for use with the
cidr and inet types.
The host
, text
, and abbrev
functions are primarily intended to offer alternative display
formats. You can cast a text value to inet
using normal casting syntax: inet(expression) or colname::inet.
Table 9-32. cidr and inet Functions
Function | Return Type | Description | Example | Result |
---|---|---|---|---|
broadcast (inet) |
inet | broadcast address for network | broadcast('192.168.1.5/24') | 192.168.1.255/24 |
host (inet) |
text | extract IP address as text | host('192.168.1.5/24') | 192.168.1.5 |
masklen (inet) |
int | extract netmask length | masklen('192.168.1.5/24') | 24 |
set_masklen (inet,
int) |
inet | set netmask length for inet value | set_masklen('192.168.1.5/24', 16) | 192.168.1.5/16 |
netmask (inet) |
inet | construct netmask for network | netmask('192.168.1.5/24') | 255.255.255.0 |
hostmask (inet) |
inet | construct host mask for network | hostmask('192.168.23.20/30') | 0.0.0.3 |
network (inet) |
cidr | extract network part of address | network('192.168.1.5/24') | 192.168.1.0/24 |
text (inet) |
text | extract IP address and netmask length as text | text(inet '192.168.1.5') | 192.168.1.5/32 |
abbrev (inet) |
text | abbreviated display format as text | abbrev(cidr '10.1.0.0/16') | 10.1/16 |
family (inet) |
int | extract family of address; 4 for IPv4, 6 for IPv6 | family('::1') | 6 |
Table
9-33 shows the functions available for use with the
macaddr type. The function trunc
(macaddr) returns a MAC address with the last 3
bytes set to zero. This can be used to associate the remaining
prefix with a manufacturer. The directory contrib/mac in the source distribution contains
some utilities to create and maintain such an association
table.
Table 9-33. macaddr Functions
Function | Return Type | Description | Example | Result |
---|---|---|---|---|
trunc (macaddr) |
macaddr | set last 3 bytes to zero | trunc(macaddr '12:34:56:78:90:ab') | 12:34:56:00:00:00 |
The macaddr type also supports the standard relational operators (>, <=, etc.) for lexicographical ordering.