N/query Module
Column.fieldId
Property Description: The name of the query result column. This property is set during the execution of Query.createColumn(options) or Component.createColumn(options). This property and the Column.formula property cannot be set at the same time.
Type: string (read-only)
Module: N/query Module
Parent Object: query.Column
Sibling Object Members: Column Object Members
Since: 2018.1
Search NetSuite - https://system.netsuite.com/app/help/helpcenter.nl?search=Column.fieldId

// Code Example 1

// Add additional code

//...

var myTransactionQuery = query.create({

    type: query.Type.TRANSACTION

});



var myAmountColumn = myTransactionQuery.createColumn({

    fieldId: 'amount'

});



var theFieldId = myAmountColumn.fieldId;

//...

// Add additional code



//SOURCE: https://system.netsuite.com/app/help/helpcenter.nl?fid=section_1510788976.html