Get power lines to maintain

In the provided GridStructure table, the fields that describe the connection between lines (EquipmentID,EquipmentID_To,EquipmentID_From) and the characteristics of the lines (e.g. Description, ConditionAssessment, VoltageLevel) are already defined.

Now, your task is to find the connected lines of the line with EquipmentID = 3 that have bad or repair as ConditionAssessment and have a VoltageLevel equal to HV. By doing this, you can answer the following question:

Which lines have to be replaced or repaired according to their description and their current condition?

You have to create a CTE to find the connected lines and finally, to filter on the desired characteristics.

Diese Übung ist Teil des Kurses

Hierarchical and Recursive Queries in SQL Server

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Anleitung zur Übung

Define the CTE maintenance_List.
Start the evaluation for line 3.
Join GridStructure with maintenance_List on the corresponding endpoints.
Use LIKE to filter the power lines with ConditionAssessment of either exchange or repair, and a VoltageLevel of HV.

Interaktive Übung

Vervollständige den Beispielcode, um diese Übung erfolgreich abzuschließen.

-- Define the table CTE
___ ___ (Line, Destination, Source, Description, ConditionAssessment, VoltageLevel) ___ (
	SELECT 
  		EquipmentID,
  		EquipmentID_To,
  		EquipmentID_From,
  		Description,
  		ConditionAssessment,
  		VoltageLevel
  	FROM GridStructure
 	-- Start the evaluation for line 3
	___ EquipmentID = ___
	UNION ALL
	SELECT 
		Child.EquipmentID, 
  		Child.EquipmentID_To,
  		Child.EquipmentID_FROM,
  		Child.Description,
  		Child.ConditionAssessment,
  		Child.VoltageLevel
	FROM GridStructure Child
  		-- Join GridStructure with CTE on the corresponding endpoints
  		___ maintenance_List 
    	ON maintenance_List.Line = Child.___)
SELECT Line, Description, ConditionAssessment 
FROM maintenance_List
-- Filter the lines based on ConditionAssessment and VoltageLevel
WHERE 
    (ConditionAssessment ___ '%exchange%' ___ ConditionAssessment ___ '%repair%') ___ 
     VoltageLevel LIKE '%HV%'

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