| PostgreSQL 7.4.22 Documentation | ||||
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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) | integer | extract netmask length | masklen('192.168.1.5/24') | 24 | 
| set_masklen(inet, integer) | 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 | 
   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.