Due to the association issue not able to bind the dropdowns and datagrids based on hierarchy :

I'm having three Entities 1.Tables(Attributes table name) 2.Region(Attributes Region name) 3.Test_Center(Attributes,  Name,code,Active) i)In table entity one of the attribute is Table_name (For displaying the table name,I need a drop down) ii)In the second drop down I need to display the region values ((If the table name is equal to "Location" means I need to display the second drop down otherwise it should be invisible ) iii) When I'm selecting the region(from second dropdown) based on the values I need to display the test center values in the Data grid.(For this I'm having (1 - *) association with Test_center from region) For this requirement I'm trying to connect Tables entity and Region entity with (1 –  *) association from Tables entity.When I'm trying to do that The association is automatically taken ( * - 1) from table to region . means here multiple table having one region (So the association wrong here) So I have taken the association from Region to table config (* - 1) and make  both entities are owners .(Now one table name having multiple region this will be correct) How I tried for this thing :  I took One dataview the source is Region  i)For displaying the table names took reference selector  ii)For displaying Region name I took Auto complete (there I'm having the constrain issue because the association is wrong here and tried with microflow . In that microflow The parameter is Table and I'm retrieving the region as list and  I passed that list to that Auto complete but the Auto complete is blank now ) . Now I’m  stuck here . Can anyone help me to do this flow of binding . Thanks in advance   
1 answers

to achieve your task 

make a SerachHelperEntity in Your Domain Model with attribute Visible boolean type by default make (/leave) it false

make   SerachHelperEntity and Region many to one [*-1] association and associate it with Test_center and Tables Entity with one to one [1-1] associations

see in screenshot

 then then go to page where you want to show your data and in dataview select datasouce to SearchHelperEntity 

then inside data view take layout grid of 6,6

then in first column put a refrence selector and select attribut to TableName by association 


then in second column of layout grid put another refrence selector and select attribute to RegionName By association

Now Select Visiblity COndion of second Refrence Selector 

After Click edit choose based on attribute Value choose visible attribute on true 

Then again go to First Refrence Selector and edit its onchnage event and call a microflow

and make your microflow in which 


firstly add a string parameter 

and in its value TableName like below (make sure association name may be vary so path will be change according to association Name)


after add parameter add a decision and check Table_name attribute value is Location or Not 

in Expression of decision 


on true condition take and change object  Activity and  and in SerachHelperEntity Set Visible to true 

and Make Sure Commit yes and Refrence in client should be yes 

same on false condition change object of SearchHelperEntity and make Visible member to false 

after it go back to your page where you are showing your data and put a list or data grid after both refrence selectors and select data souce a microflow and Create New Microflow for example OCH_Region_ListGet , and make sure refresh in data grid should be on in seconds 

in data grid 


now go to your newly created microflow and write OQL to fetch your test_center data 

i hope you know how to use OQL (for OQL download OQl and community commons from marketplace  and if any error occurs  remove pages from atlas view pages that giving errors) in mendix if you are not new in mendix 

so in microflow 

firstly add a string parameter

and put value to RegionName ( in value of parameter ) = $SearchHelperEntity/MyFirstModule.SearchHelperEntity_Region/MyFirstModule.Region/RegionName

then Execute OQL 

'SELECT test.Name as Name ,test.Code as Code,test.Active as Active
FROM MyFirstModule.Region as region
INNER JOIN region/MyFirstModule.Test_Center_Region/MyFirstModule.Test_Center as test
WHERE region/RegionName =$RegionName'


and set another parameter according to picture 

and in end Event return that list 

now go to your data grid and click on a colum and by drag and drop from connector tab set all column attributes 

now your all configuration done 

i hope it will help you