Example from server.xml:
<Resource
name="jdbc/myresource"
type="javax.sql.DataSource"
password="mypassword"
driverClassName="com.ibm.as400.access.AS400JDBCDriver"
maxIdle="5"
maxWait="5000"
username="xxxxxxxxxx" 
url="jdbc:as400:www.xxxxxxxxxxxx.com;libraries=lib1 lib2 lib3;prompt=false"
maxActive="10"/>

And from context.xml:
<ResourceLink global="jdbc/myresource" name="jdbc/myresource" type="javax.sql.DataSource"/> 

package com.dandarnell.client;

// ^ This package is JavaScript generation only.

import org.eclipse.edt.rui.widgets.*;
import com.dandarnell.common.*;
import com.dandarnell.server.HelloDatabaseService;

handler HelloDatabase type RUIhandler{initialUI =[ui], onConstructionFunction = start, cssFile = "css/HelloDatabase.css", title = ""}

    ui GridLayout{columns = 3, rows = 4, cellPadding = 4, children = [ l1, t1, l2, l3, b1 ]};
    b1 Button{ layoutData = new GridLayoutData{ row = 4, column = 1 }, text = "Say Hello", onClick ::= b1_onClick };
    t1 TextField{ layoutData = new GridLayoutData{ row = 1, column = 2 }};
    l1 TextLabel{ layoutData = new GridLayoutData{ row = 1, column = 1 }, text = "ID:" };
    l2 TextLabel{ layoutData = new GridLayoutData{ row = 2, column = 2 }, text="" };
    l3 TextLabel{ layoutData = new GridLayoutData{ row = 3, column = 2 }, text="" };

    function start()
    end
    
    function b1_onClick(event Event in)
    	
    	call HelloDatabaseService.getCustomerWithStatus(t1.text as int)
    		returning to myCallBackFunction
			onException myExceptionHandler;
    end
    
    function myCallBackFunction(retResult CustomerWithStatus in)
		
		if(retResult.status.succeeded)
    		l2.text = "Hello, " + retResult.data.firstname;
    	end
    	
    	l3.text = "DB Status: " + retResult.status.message;
    end
    
    function myExceptionHandler(exp AnyException in)
		SysLib.writeStdOut(exp.messageID + " " + exp.message);
 
		if(exp isa ServiceInvocationException)
			SysLib.writeStdOut((exp as ServiceInvocationException).detail1);
			SysLib.writeStdOut((exp as ServiceInvocationException).detail2);
			SysLib.writeStdOut((exp as ServiceInvocationException).detail3);
		end

	end

end

package com.dandarnell.common;

// ^ This package is Java and JavaScript generation.

Record Status
	succeeded boolean;
	message string?;
end
record Customer type Entity { @table { name="CUSTOMER" } }
	id int{ @id };
	firstname string(40);
end
Record CustomerWithStatus
	status Status;
	data Customer?;
end

package com.dandarnell.server;

// ^ This package is Java generation only.

import com.dandarnell.common.*;

service HelloDatabaseService

	dataSource SQLDataSource? { @Resource{uri = "binding:dbbinding"}};  

	function getCustomerWithStatus(id int in) returns (CustomerWithStatus)

		ret CustomerWithStatus{};
		rec Customer?;
		ret.status.succeeded = false;
		ret.status.message = "Unknown error";
		
		try
			get rec from dataSource using(id);
 			
			if(rec == null)
				ret.status.message = "Record not found";
			else
				ret.status.succeeded = true;
		                ret.status.message = "Ok";
				ret.data = rec;
			end

		onException (exception SQLException)
			ret.status.message = exception.message;
		end
		
		return (ret);
	end
	
end

CREATE TABLE DDARNELLDT/CUSTOMER (
  ID INT NOT NULL WITH DEFAULT,    
  FIRSTNAME VARCHAR ( 40) NOT NULL WITH DEFAULT,
  CONSTRAINT ID_KEY   
  PRIMARY KEY (ID))                                                  

INSERT INTO DDARNELLDT/CUSTOMER VALUES(1, 'Dan')    
INSERT INTO DDARNELLDT/CUSTOMER VALUES(2, 'Joe')