Hi,

I'm trying to create an update  function for a custom object. In my Visualforce code, there's a commandLink to perform the work. When pressing the link I call a method in my controller that updated the record which ID is passed as a parameter. However, it doesn't work and I get the following error:

System.LimitException: DML currently not allowed

Class.MyRequestsController.approveRequest: line 135, column 3 External entry point

here is part of my code:

<apex:pageBlockTable value="{!currentQueryBatch}" var="query" columns="7" styleClass="query-table">
		            <apex:column headerValue="Request Number"><a href="requestTicket/RequestDetailsView?id={!query.id}"><apex:outputText value="{!query.Name}"/></a></apex:column>
		            <apex:column headerValue="Subject" value="{!query.Subject__c}"/>
		            <apex:column headerValue="Status" value="{!query.Status__c}"/>
		            <apex:column headerValue="Team" value="{!query.Team_Name__c}"/>
		            <apex:column headerValue="Date" value="{!query.CreatedDate}"/>
		            <apex:column headerValue="OwnerId" value="{!query.OwnerId}"/>
		            <apex:column headerValue="Approval Status" value="{!query.Approval_Status__c}" rendered="{!OR(openQueriesDisplayed,closedQueriesDisplayed)}"/>
		            <apex:column rendered="{!approvalQueriesDisplayed}">
                		<apex:facet name="header">Action</apex:facet>
                        	<apex:commandLink value=" Approve " action="{!approveRequest}">
                        	<apex:param name="queryId" assignTo="{!queryId}" value="{!query.Id}" />
                        	</apex:commandLink>
            	            </apex:column>
</apex:pageBlockTable>

 please, help