Use of SELECT statement in esql

                      Using ESQL SELECT statement

The SELECT function combines, filters, and transforms complex message and database data.

SELECT function in esql

Input xml:

-------------

<Person>

 <Details>

  <ID>1</ID>

  <Name>Arun</Name>

 </Details>

 <Details>

  <ID>5</ID>

  <Name>Shyam</Name>

 </Details>

 <Details>

  <ID>1</ID>

  <Name>Arun</Name>

 </Details>

 <Details>

  <ID>3</ID>

  <Name>Priyesh</Name>

 </Details>

</Person>

Scenario :

------------

From above input we need name when ID=5.

To get this, the best approach in esql is bellow -

Solution :

------------

--Declare a reference to the root.

DECLARE InRef REFERENCE TO InputRoot.XMLNSC.Person;

--Now assign the value to output using select function 

SET OutputRoot.XMLNSC.Data.Person.Name = THE(select item fieldvalue(r.Name) from InRef.Details[] as r where r.ID = 5);