@ judges whether the current node/edge belongs to a given schema, and is often overlaid with property call.

• Expression: @<schema>
• Operand: string constant

Schema checker exists only in Ultipa filter, and cannot appear as an expression in a UQL clause.

Node

Example: find and return 10 Cards with their properties

find().nodes({@card}) as n
limit 10
return n{*} 

Analysis: we can also use another expression {@ == "card"}, see Conditional Operators ==.

Edge

Example: find and return 10 @transfer edges with their properties

find().edges({@transfer}) as e
limit 10
return e{*} 

Schema & Property

Example: find Cards whose balance is over 500000, return 10 cards with all properties.

find().nodes({@card.balance > 500000}) as n
limit 10
return n{*} 

Analysis: this filter can be extended as {@card && balance > 500000}, see Conditional Operators &&.