Undocumented encoded JOIN query syntax?

[treycarroll]

All,

I have found a strange piece of code in in the OOTB Script Include "ChangeCollisionHelper":

/**
 * Get all the CI GlideRecords that depend on the given CI
 *
 * return GlideRecord
 */
ChangeCollisionHelper.getCIDependants = function (ciSysId) {
  var dependentsGR = new GlideRecord("cmdb_ci");
  dependentsGR.addQuery(
    "JOINcmdb_ci.sys_id=cmdb_rel_ci.parent!child=" + ciSysId
  );
  dependentsGR.query();
  return dependentsGR;
};

I don't recognize this Syntax.   

#1 It looks like an encoded query, but it just uses addQuery.

#2  The comment says that it gets all the cis that depend on the given CI, so that would seem to say that we were looking for its parents.  Fascinatingly, "!child=" + ciSysId acts like a Where clause.

This actually works.  It's baked into the Script Includes that run the Change module.  Is there some documentation that I am just not seeing?

Try this in your PDI if you want to see it work:

var r = getCIDependants('27e52cc8c0a8000b0067d0b66b8a66de');
while(r.next()){
	for(var k in r){
		gs.print(k + '::' + r[k])
	}	
}


function getCIDependants (ciSysId) {
  var dependentsGR = new GlideRecord("cmdb_ci");
  dependentsGR.addQuery(
    "JOINcmdb_ci.sys_id=cmdb_rel_ci.parent!child=" + ciSysId
  );
  dependentsGR.query();	
  return dependentsGR;
}

Link to the CI parameter record: 

https://dev<your instance #>.service-now.com/nav_to.do?uri=cmdb_ci_server.do?sys_id=27e52cc8c0a8000b0067d0b66b8a66de

Regards,

Trey Carroll

[DrewW]

addJoinQuery can help you along

https://developer.servicenow.com/dev.do#!/reference/api/orlando/server_legacy/c_GlideRecordAPI#r_Gli...

[treycarroll]

The entire crux of my question is regarding the use by ServiceNow in core modules of a strange but powerful, undocumented query string syntax for performing a Where and a JOIN.  (Something that we feature requested and were refused ~6 years ago.) The addJoinQuery method is something else.  I think that this new functionality it actually an incredible tool.

[DrewW]

This is not new functionality, its been part of the system for a long time.  The addJoinQuery allows you to do the same thing as the encoded query you found just not as an encoded query.  If you setup a test case and use a addJoinQuery and then use a getEncodedQuery you will see the same syntax. I do agree that the encoded query syntax is not documented but they also left out documentation for related list queries and those have been available for at least 4 years.