<apex:page controller="QueryController" >
  <apex:form >
      <apex:pageBlock >
          <apex:inputText value="{!query}" style="width: 1000px; margin: 10px"/>
          <apex:commandButton action="{!execute}" value="Execute" style="width: 200px; height: 30px; background:#fc0000 "/>
          <apex:pageMessage summary="Query error." severity="warning" strength="3" rendered="{!flag}" />

           <apex:pageBlockTable id="table" var="object" value="{!objects}">
                <apex:repeat var="field" value="{!object.objFields}">
                    <apex:column headerValue="No matter how this is defined, it results in an empty cell">
                    <apex:outputText value="{!field.value}" />
                    </apex:column>
                    </apex:repeat>
                    <!--Define the headers here and hide the empty cells that are created -->
                    <apex:repeat var="fieldH" value="{!object.objFields}">
                    <apex:column headerValue="{!fieldH.label}" styleClass="empty-column-content" />
               </apex:repeat>
    </apex:pageBlockTable>

      </apex:pageBlock>
  </apex:form>
</apex:page>