Access shortcut key

[slowlearner2014]

I remember there is shortcut keys for input field name when creating a queries. For example, when we try to create a query to combine field [firstname] and field [lastname] from customer table and we use: fullname:[firstname]+" "+[lastname]; instead of input this expression {fullname:[firstname]+" "+[lastname]} key by key, is there shortcut key that can input [firstname] into expression? Thanks.

[June7]

Am not aware of shortcut key for that.

BTW, & is the preferred concatenation operator instead of +.