Can i access database table value using a constant?

Question

Hi, 
 
 I have a table where username and password is stored , now in an interface i want to access password based on the username, can it be possible to access data from dB using a constant in the interface?

Furman · Answer

I would rather use Appian expression and a!queryEntity function.

Swetha Pokuri · Answer

. a!queryEntity(
 entity: cons!TTC_USERDETAILS,
 query: a!query(
 logicalExpression: a!queryLogicalExpression(
 operator: "AND",
 filters: {
 a!queryFilter(
 field: "userName",
 operator: "=",
 value: ri!userName
 )
 },
 ignoreFiltersWithEmptyValues: true
 ),
 pagingInfo: a!pagingInfo(
 startIndex: 1,
 batchSize: 50,
 sort: a!sortInfo(
 field: "userId",
 ascending: true
 )
 )
 ),
 fetchTotalCount: false
) 
 
 By using a!queryentity we will fetch the data from the back end tables and directly we can use this expressions in the interface. for better understanding 
 please go through the above code .