fetch Data from a db column to drop down component

Question

Hi All, 
 
 I'm trying to fetch data form one of the column of database to the drop down component on UI. 
 Column has redundant data e.g india,india,india, in 100 rows let say. 
 I'm using index(local!variable,"columnname" {}) function, but it is throwing error.. Duplicate items are not allowed in the choice Values array. 
 Please guide on this .. 
 
 TIA, 
 Nalini

sureshg57 · Answer

nalinib0001 
 
If you are fetching the initial data using a query entity or even calling an Stored Procedure, we can use groupby using the column which is required. This will get unique data for the column and no need to doing extra manipulation of data in Appian side. 
 
for ex: 
 
local!mydropdownlaluves: a!queryEntity( 
 entity: cons!MY_DATASTORE, 
 query: a!query( 
 aggregation: { 
 a!queryAggregation( 
 aggregationColumns: a!queryAggregationColumn( 
 field: "MY_VALUE_COLUMN", 
 isGrouping: true() 
 ) 
 ) 
 }, 
 pagingInfo: rule!APN_pagingInfoAll() 
 ) 
) 
 
Regards 
Suresh