Lightning Datatable using Fieldset

1. Create a util class (FieldSetExample) which is responsible to return list of fields (label, api and       type) available under field set of an object passed as parameters by a method.

public class FieldSetExample {
    /**
     * This method is responsible to return list of fields (label, api and type) avaliable
     * under field set of an object passed as parameters.
     * */
    public static List<FieldSetProperties> getFieldFromFieldSet(String objApi, String fieldSetName){
        List<FieldSetProperties> lstOfWrapper = new List<FieldSetProperties>();
        
        Schema.SObjectType sObjType = Schema.getGlobalDescribe().get(objApi);
        Schema.DescribeSObjectResult desSObjRslt = sObjType.getDescribe();            
        Schema.FieldSet fieldSetIns = desSObjRslt.FieldSets.getMap().get(fieldSetName);
        
        for( Schema.FieldSetMember fieldSetMember : fieldSetIns.getFields() ){
            FieldSetProperties wrapperIns = new FieldSetProperties();
            
            wrapperIns.label = String.valueOf(fieldSetMember.getLabel()); 
            wrapperIns.fieldName = String.valueOf(fieldSetMember.getFieldPath()); 
            wrapperIns.type = String.valueOf(fieldSetMember.getType()).toLowerCase();
            
            lstOfWrapper.add(wrapperIns);
        }        
        
        return lstOfWrapper;
    }
    
    /**
     * Wrapper class to hold fieds properties like label, field api and field type.
     * */
    public class FieldSetProperties{
        @AuraEnabled
        public String label;
        @AuraEnabled
        public String fieldName;
        @AuraEnabled
        public String type;
    }
}

2. Create a server side controller class (DataTableExampleController) for the lightning component (dataTableExample) used to display records using data table.

public class DataTableExampleController {
    
    @AuraEnabled
    public static DataTableDetails getDataTableDetails(String objApi, String fieldSetName){
        DataTableDetails dataTableDtls = new DataTableDetails();
        List<FieldSetExample.FieldSetProperties> lstOfFieldSetProperties = FieldSetExample.getFieldFromFieldSet(objApi, fieldSetName);
        
        if(lstOfFieldSetProperties != null && lstOfFieldSetProperties.size() > 0){
            String strQuery = 'SELECT ';
            for(FieldSetExample.FieldSetProperties inst : lstOfFieldSetProperties){
                dataTableDtls.lstOfFieldLabels.add(inst);
                
                strQuery = strQuery + inst.fieldName + ',';
            }
            if(!strQuery.equalsIgnoreCase('SELECT '))
                strQuery = strQuery + 'Id FROM ' + objApi;
            
            dataTableDtls.lstOfSObjs = Database.query(strQuery);
        }
        
     return dataTableDtls;
    }
    
    
    public class DataTableDetails{
        @AuraEnabled
        public List<sObject> lstOfSObjs = new List<sObject>();
        @AuraEnabled
        public List<FieldSetExample.FieldSetProperties> lstOfFieldLabels = new List<FieldSetExample.FieldSetProperties>();
    }
}

3. Create the lightning component (dataTableExample.cmp).

<aura:component controller="DataTableExampleController">
    <aura:attribute name="lstOfRecords" type="Object"/>
    <aura:attribute name="columnsHeader" type="List"/>
    <aura:handler name="init" value="{!this}" action="{!c.doInit}"/>
        
    <lightning:datatable data="{!v.lstOfRecords}"
                         columns="{!v.columnsHeader}"
                         keyField="Id"
                         hideCheckboxColumn="true"/>
</aura:component>

4. dataTableExampleController.js

({
    doInit : function(component, event, helper) {
         helper.getDataTableRespone(component, event);
    }
})

5. dataTableExampleHelper.js

({
 getDataTableRespone : function(component, event) {
        var action = component.get("c.getDataTableDetails");
        action.setParams({
            objApi : 'YOUR OBJECT API',
            fieldSetName : 'YOUR FIELD SET NAME'
        });
        action.setCallback(this, function(response){
            var state = response.getState();
            if(state === 'SUCCESS'){
                //console.log('::::::::::::: SUCCESS :::::::::::::'+JSON.stringify(response.getReturnValue().lstOfFieldLabels));
                component.set("v.columnsHeader", response.getReturnValue().lstOfFieldLabels);
                
                component.set("v.lstOfRecords", response.getReturnValue().lstOfSObjs);    
            }else if (state === 'ERROR'){
                console.log('::::::::::::: ERROR :::::::::::::');
            }
        });
        $A.enqueueAction(action);
 }
})

6. Call the above component from an application (dataTableExampleApp.app)

<aura:application extends="force:slds">
 <c:dataTableExample />
</aura:application>