The SQL repository query system also lets you create a query against a parent item descriptor that returns items of a child item descriptor. For example, suppose you have the following item descriptors and properties:
productsitem descriptor (parent item type)
Properties:pricenameshoesitem descriptor (super-type = “products”)
Properties:sizewaterproofRatingelectronicsitem descriptor (super-type = “products”)
Properties:powerRequirementswaterproofRatingradiositem descriptor (super-type=“electronics”)
Properties:channelCount
You can then create queries like these, even though the products item descriptor does not include waterproofRating, size, or channelCount properties:
products whose waterproofRating is 'JIS-4'
products whose channelCount = 7
products whose waterproofRating is 'JIS-4' OR whose size > 7
