visual studio lightswitch - Using the PreprocessQuery method in a Local Query -

i've master/detail relationship 1 shown in picture below

i need filter data shown in orderheaders table i've edited local query (by clicking edit query link in screen) part of filter based on computed property need use preprocessquery method because computed properties doesn't appear in query's "filter" section.

but i've problem, in local query "write code" combobox not available in global query shown in picture below

so don't know how create preprocessquery method in local query.

can tell me how create it?

if it's not available local queries there way filter computed property?

ok first create subquery table. such productswithoudescription , sortedproducts right clicking table , "adding query". (country supposed equivalent of "headers" table)

name query, add parameter query of whatever type need.

now write code it: (here country table i'm using)

note newparameter "parameter" method. filter query display records countryname equal parameter. can have many parameters need.

now add data item screen.

then add new property of type need well.(its under add data item well)

i recommend uncheck is required.

here basic query layout screen. used table locations example every location has country in data model. locations supposed equivalent of customer table. if expand locations(you customers) table notice can't add newly created query directly. notice property created displayed.

if expand new query on left youll see parameter @ bottom.

click on it, properties (f4) , map parameter newly created property.

now filtering parameter set property created.

now have set property before query can display anything. heres how it:

select customer(mine locations) table , @ top left click down arrow next write code , select `selectionchanged' method:

now write code:

here display string computed field of locations. every time select in locations grid, use "displaystring" filter "mynewfavoritequery".

some things note:

it make parameter subquery optional query display without filtering long property null. (actually im not sure 1 since im using little bit differently, can play around , see get)

if set property required cause validation erros on screen if property set null.

you may have fine tune property initialized null when screen created. can edit "screecreated" method under general in write code set value property when screen first generated.

let me know if have questions.