Filtering by the ID of the Source

The most basic source filter is used to limit the sources supplied to a query by providing the Source Id or the External Id of each source that you wish to include in the filtered result set.

By External Id

The ExternalIdFilter includes those sources whose external Ids are listed in a %List structure. Any element in this list that is not a valid External Id, or is a duplicate external Id is silently passed over.

The following example filters sources by external Id. The external Id for Aviation.Event sources includes either the word “Accident” or “Incident”; this filter include only the sources whose external Id includes the word “Incident”. It then lists the details of the filtered sources:

DomainCreateOrOpen
  SET dname="mydomain"
  IF (##class(%iKnow.Domain).NameIndexExists(dname))
      { SET domoref=##class(%iKnow.Domain).NameIndexOpen(dname)
        GOTO DeleteOldData }
  ELSE { SET domoref=##class(%iKnow.Domain).%New(dname)
         DO domoref.%Save()
         GOTO SetEnvironment }
DeleteOldData
  SET stat=domoref.DropData()
  IF stat { GOTO SetEnvironment }
  ELSE    { WRITE "DropData error ",$System.Status.DisplayError(stat)
            QUIT}
SetEnvironment
  SET domId=domoref.Id
  IF ##class(%iKnow.Configuration).Exists("myconfig") {
         SET cfg=##class(%iKnow.Configuration).Open("myconfig") }
  ELSE { SET cfg=##class(%iKnow.Configuration).%New("myconfig",0,$LISTBUILD("en"),"",1)
         DO cfg.%Save() }
ListerAndLoader
  SET domId=domoref.Id
  SET flister=##class(%iKnow.Source.SQL.Lister).%New(domId)
  SET myloader=##class(%iKnow.Source.Loader).%New(domId)
QueryBuild
   SET myquery="SELECT TOP 100 ID AS UniqueVal,Type,NarrativeFull FROM Aviation.Event"
   SET idfld="UniqueVal"
   SET grpfld="Type"
   SET dataflds=$LB("NarrativeFull")
UseListerAndLoader
  SET stat=flister.AddListToBatch(myquery,idfld,grpfld,dataflds)
      IF stat '= 1 {WRITE "The lister failed: ",$System.Status.DisplayError(stat) QUIT }
  SET stat=myloader.ProcessBatch()
      IF stat '= 1 {WRITE "The loader failed: ",$System.Status.DisplayError(stat) QUIT }
DefineExtIdFilter
  DO ##class(%iKnow.Queries.SourceAPI).GetByDomain(.result,domId,1,100)
  SET i=1
  SET extlist=$LB("")
  WHILE $DATA(result(i)) {
        SET extId = $LISTGET(result(i),2)
        IF $PIECE(extId,":",3)="Incident" {
        SET extlist=extlist_$LB(extId) }
        SET i=i+1
  }
  SET filt=##class(%iKnow.Filters.ExternalIdFilter).%New(domId,extlist) 
SourceCountQuery
  SET numSrcD=##class(%iKnow.Queries.SourceAPI).GetCountByDomain(domId)
  WRITE "The ",dname," domain contains ",numSrcD," sources",!
ApplyExtIdFilter
  SET numSrcFD=##class(%iKnow.Queries.SourceAPI).GetCountByDomain(domId,filt)
  WRITE "The Id filter includes ",numSrcFD," sources:",!
  DO ##class(%iKnow.Queries.SourceAPI).GetByDomain(.result,domId,1,100,filt)
       SET j=1
       WHILE $DATA(result(j)) {
         SET intId = $LISTGET(result(j),1)
         SET extId = $LISTGET(result(j),2)
         WRITE intId," ",extId,!
         SET j=j+1
      }
      WRITE "End of list"

By Source Id

The SourceIdFilter includes those sources whose source Ids are listed in a %List structure. Source Ids are integers. They can be listed in any order. Any element in this list that is not a valid source Id, or is a duplicate source Id is silently passed over.

The following example takes SQL records as sources and filters in several sources by Source Id. Source Ids in this data set are numbered 1 through 100. The SourceIdFilter specifies five source Ids for inclusion, but only three of these source Ids correspond to records in the table. Therefore, the total filtered source count is 3:

DefineAFilter
  SET srclist=$LB(10,14,74,110,2799)
  SET filt=##class(%iKnow.Filters.SourceIdFilter).%New(domId,srclist)
SourceCounts
  SET numsrc = ##class(%iKnow.Queries.SourceAPI).GetCountByDomain(domId)
     WRITE "The ",dname," domain contains ",numsrc," sources",!
 SET numfsrc = ##class(%iKnow.Queries.SourceAPI).GetCountByDomain(domId,filt)
     WRITE "Source count after source Id filtering: ",numfsrc

The iKnow.Filters.Filter class includes the %iKnow.Filters.SourceIdRangeFilter subclass. The following example filters a range of sources by source Id. It returns sources with source Ids 5 through 10, inclusive:

  SET filt=##class(%iKnow.Filters.SourceIdRangeFilter).%New(domId,5,10)

Filtering a Random Selection of Sources

Supported Filters