Qualified and Unqualified Paths

PQL supports both qualified and unqualified pathes. A qualified path is a path that is restricted with the conditions, such as:
interface[name='eth0']. An unqualified path, or simple path, contains no conditions, such as: interface/name.

Example 1: Simple Paths

This query fetches all known information about the interface named eth0 that has the MAC address of 12:10:D8:99:2B:C2:

SELECT interface
FROM /network/device
WHERE interface/name = 'eth0' 
AND interface/mac_address = '12:10:D8:99:2B:C2'

When run against the sample database, this query displays all the information about the specified interface:

row
  interface
    interface
      name eth0
      mac_address 12:10:D8:99:2B:C2
      in_octets 1385354750
      out_octets 1451321493
      oper_status 1
    interface
      name eth1
      mac_address 13:10:D8:99:2B:C1
      in_octets 3312952833
      out_octets 3239791359
      oper_status 1

Example 2: Conditional path

This example query finds the operating status of a specific interface:

SELECT interface[name = 'eth0']/oper_status
FROM /network/device
WHERE interface[name = 'eth0']/mac_address = 
   '12:10:D8:99:2B:C2'

When run against the sample database, this query displays the operating status of the specified interface:

row
  interface/oper_status
    oper_status 1

Example 3: Broader conditional path

A more useful query might be one that returns all the data that's known about the interface node, like this:

SELECT interface 
FROM /network/device 
WHERE interface[name = 'eth0']/mac_address = 
   '12:10:D8:99:2B:C2'

This query lists all the data about the specified interface, including the oeprating status:

row
  interface
    interface
      name eth0
      mac_address 12:10:D8:99:2B:C2
      in_octets 1385354750
      out_octets 1451321493
      oper_status 1
    interface
      name eth1
      mac_address 13:10:D8:99:2B:C1
      in_octets 3312952833
      out_octets 3239791359
      oper_status 1

Note how this query returned both interfaces from the device, even though the WHERE clause used a specific interface to find the device. The next example is probably more useful.

Example 4: Narrower conditional path

You can narrow the query so that it returns nothing but the name of a single interface, like this:

SELECT interface[mac_address='12:10:D8:99:2B:C2']/name              
FROM /network/device 
WHERE interface/mac_address='12:10:D8:99:2B:C2'

This query returns only the name of the one interface that has a matching MAC address of '01:01:02:03:04:05':

row
   interface[mac_address = 12:10:D8:99:2B:C2]/name eth0

Example 5: All devices in a given subnet

This query uses a qualified path that limits the results to a specific subnet. To use this against your own Paglo account, adjust the IP addresses.

SELECT nvl(system/name, system/dns_name) as "Name", 
  nvl(system/model, system/class, 
  wmi/win32_computersystem/domainrole) as "Type",
  interface[inet/ip_address like '1.1.1.']/inet/ip_address 
  as "IP Address", last_seen from /network/device 
WHERE system is not null 
AND interface/inet/ip_address like '1.1.1.'

Depending on the database, this query returns results that work well in a table, like this:

row
   Name cannes-server.acme.local
   Type null
   IP Address 1.1.1.1
   last_seen 2008-04-17T00:02:01.0000000Z
row
   Name HP ProCurve
   Type HP J4093A ProCurve Switch 2424M, 
        revision C.09.19, ROM C.06.01 
        (/sw/code/build/vgro(c09))
   IP Address
     ip_address 1.1.1.2
     ip_address 1.1.1.2
   last_seen 2008-04-17T01:06:25.0000000Z
row
   Name amsterdam.acme.local hq.acme.com
   Type null
   IP Address 1.1.1.3
   last_seen 2008-04-15T17:31:32.0000000Z
row
   Name berne-server.acme.local
   Type 1 Member Workstation
   IP Address 1.1.1.4
   last_seen 2008-04-17T00:04:37.0000000Z
   . . .