How to retrieve two columns data (both are Text type) from a Table in Appian DB in chronological order/ascending order?

Question

Scenario: Trying to retrieve data from two Text columns as a single array of items in chronological order/ascending order. A Query rule can order by only one column. But need to retrieve a combined list that is sorted. 
 Currently when tried something like {rule!GetSourceList, rule!GetRecipientList}, the data is in order for each of the query rules standalone but when combined with that {,} i am getting something as follows: 
 Alisha; Akhil; Daniel; Alexa; Beatle; 
 As you can see names with A are repeated instead of in chronologial order, because Alexa; Beatle; belong to different column retrieved with separate query rule. 
 Please advise on how to do it with single query rule or by any other way? 
 Please advise.

Dan Lluhi · Answer

Hi, I would recommend running a single query with no sorting to pull back both columns. Then you can append() the values from column 1 to the values from column 2 and save it to a simple text array variable. From here, convert the list of text to an array of CDTs and set one of the fields to your text values (to do this you can use a!forEach over the list of text, and set the expression to be type!My_CDT(fieldName:fv!item)). Once you have a list of CDTs that have all of values you want to sort, you can use the function described in this post: community.appian.com/.../sort-a-cdt-array-based-on-a-field to sort your list. 
 
Thanks, 
Dan

jonathan.guillen · Answer

Hello, 
 You can create a query entity within an expression rule. 
 
 inside of your paging info, you can create a list of sort info elements. 
 i.e: 
 pagingInfo: a!pagingInfo(
 startIndex: 1,
 batchSize: - 1,
 sort: {
 a!sortInfo(
 field: "column_A",
 ascending: true
 ),
 a!sortInfo(
 field: "column_B",
 ascending: true
 )
 }
) 
 
 Another option is creating a query inside of your database with the information required and then that query can be called using a smart service. 
 Basically depends on the complexity of your problem. 
 regards.