fetch Data from a db column to drop down component

Hi Nalini ,

For choice values it won't allow duplicate values for ignoring that
can you try the bellow

load(

local!data:index(local!variable,"columnname" {})
-------
-------
------..etc,
a!dropdownField(

label: " ",
placeholderLabel: "--select --",
choiceLabels: union(
local!data,
local!data
),
choiceValues: union(
local!data,
local!data
),
value: {},
saveInto:{}
)

may it helps you.....

Thanks

The values must be unique. As mentioned in the response, union will remove duplicates. However, the better approach may be to create a lookup table of values. That table should have and ID (pk) and text. The ID can be a number (sequence) for normalization or the text value.
If you are querying a table that just continues to grow and have more and more records, the union will start to slow and may degrade performance.

Thanks will try this..

Thanks will try it!!

Hi Nalini,

I am guessing the table which you are using the populate the data in your drop down component is not lookup table. So use look up table from where these data (india,india,india,......) is coming then your drop down will work, no need to use any functions.

But still you are facing the issue then use code suggested by Prakash with slightly change,it will give you better performance :

load(

local!data:index(local!variable,"columnname" {})
local!dropDownOptions: union(
local!data,
local!data
),
-------
-------
------..etc,
a!dropdownField(

label: " ",
placeholderLabel: "--select --",
choiceLabels: local!dropDownOptions,
choiceValues:local!dropDownOptions,
value: {},
saveInto:{}
)

Regards
Abhay

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

Yes, you don't want to waste bandwidth pulling more data than you need only to remove duplicates after you've pulled.

Another option would be to create a constant with all the unique values, along with a Stored Procedure you can call when needed or on a schedule to update the constant to match the lookup table. This way, you run the query say every 2 weeks instead of every single time any user goes to the form that uses the dropdown. You need to look at how frequently this list of unique values changes. If it's not that frequent you might consider this option. If it doesn't change (every new row uses a value that has already been used before), I would do only the constant and no SP or query at all.

Thanks for the code..

ok Got it ,Thanks

Hi,
Follow these steps:
1. write query entity to fetch that column
2. save only that column data in a local variable, let's suppose local!a
3. give local!finalData: union(local!a,local!a)
4. use local!finalData in choiceValues and choiceLabels

Note: 3rd step might give error saying can't perform union on local!a, in this scenario write below line:
local!finalData: union(touniformString(local!a),touniformString(local!a))