The screenshot on the right shows the configuration for a Singular attribute join that controls multiple access to the singular attribute 'PositionXyz' (PositionXyz):

• No Attribute owner path is required to access the attributes of the main entity of the CSV search.
  
  

• 'PositionXyz' (PositionXyz) is selected as the Attribute.
  
  

• The name pos is randomly assigned as the Join alias.

• For Join type and Optional, the default (Left/Optional) is retained so that 'Points of Interest' without position information are also considered matches.
  
  

• It is not necessary to define a On condition.

The detailed data from the PositionXyz attribute can be addressed via the Join alias pos for the Singular attribute join with multiple instances of the Property projection in Projections for output columns:

• The first Property projection names the 'point of interest' based on a property of the main entity.
  
  

• The following three Property projection instances first refer to the Join alias pos and then retrieve a specific detail (x, y, z) from its value property.
  
  ► NOTE◄ The use of descriptive column names (such as LATITUDE, LONGITUDE, ELEVATION) has only been omitted here so that the paths can be read when collapsed.

As shown on the right, the CSV search may also return output lines for which no position information is available.

►NOTE◄ The same result could be achieved if the Singular attribute join were omitted and three instances of the Singular attribute projection were used instead.

POI_NAME,pos.value.x,pos.value.y,pos.value.z
================================================
GREENWICH_PRIME_MERIDIAN,51.47781,-0.00148,223.0
TAJ_MAHAL,27.175,78.04194,240.0
PLANET_EARTH,,,
TOUR_EIFFEL,48.85822,2.2945,108.0

The Singular attribute join can be adjusted as shown on the right to exclude 'point of interest' instances without any position information:

• The Join type has been changed to 'Inner'.
  
  

• The Optional option can remain checked.
  
  

• A Field restriction has been introduced as an On condition, which checks whether the value property of any attribute found is not (!=) empty.

►IMPORTANT◄ If the On condition was omitted, the case would not be covered if a 'point of interest' was saved at least once with a position specification whose detail fields (x, y, z) have since been deleted. An empty shell then remains for the attribute, unless this is removed by an explicitly configured event handling when saving.

The On condition shown on the right does not evaluate data from the Singular attribute join as an exception, but refers to the context of the session in a Field restriction with a trick:

• A Literal projection provides the static Boolean value true as the check value (left).
  
  

• The compare value (right) is also a static boolean value from the perspective of the search, which is obtained as the return value of a Role rule via a Rule value resolver before the search is executed. The Role rule checks whether a specific Role of session (here: 'Querificus') is registered, or whether the Role of session is directly or indirectly subordinate to this role.

►IMPORTANT◄ Based on the variant (above), the Join type must be changed to 'Left'. With the Join type 'Inner', not only would the output columns for the position remain empty, but all result rows would be excluded.