FIrst look at Dynamic APEX

Kyle
Roche

I opened a case in my Dev org a few days ago to request that Dynamic APEX be enabled. I took my first look at it today. The first step required to take a look at Dynamic APEX is to open a case in your development org. It took about 48 hours to get the setting enabled. The rest of this post and the follow up posts assume that step has been completed.

Start by creating a new Visualforce page. I'm using a page called /apex/dynamicApex. I created a custom controller called dynamicApexController by changing the <apex:page> component as follows:

<apex:page controller="dynamicApexController">

Let's start with the controller. Switch your editor to the controller view and add the following APEX Property. As in my previous posts, I'm using APEX Properties in place of the old getters / setters. For more information on APEX Properties see the Summer 08 Developer's Guide.

public List<Account> DynamicAccountList
{
get
{
if (DynamicAccountList == null)
{
string myDynamicQuery = 'select id,name from Account limit 10';
DynamicAccountList = Database.Query(myDynamicQuery);
}
return DynamicAccountList;
}
set;
}

Now, this is obviously a basic example. I'll extend this using some more complicated situations in the coming posts. Since we have Dynamic APEX enabled we can now use Dynamic SOQL, SOQL and DML. We're creating a string to hold our Dynamic SOQL query. We can then pass the string to be evaluated at runtime to the Database.Query() method. The possibilities for customization are endless.

To display the results on the Visualforce Page add a quick dataTable component.

<apex:dataTable value="{!DynamicAccountList}" var="acct">
<apex:column value="{!acct.id}"></apex:column>
<apex:column value="{!acct.name}"></apex:column>
</apex:dataTable>

We'll look at some examples of dynamic queries built on user input in the following posts in this series.