import java.util.ArrayList;
import java.util.Collection;
import org.joget.commons.util.LogUtil;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.sql.DataSource;
import org.joget.apps.app.service.AppUtil;

//list down all approvers
Collection assignees = new ArrayList();

assignees.add("cat");
assignees.add("jack");
assignees.add("mike");

//find out who has already approved and remove them from assignees

Connection con = null;
try {
    // retrieve connection from the default datasource
    DataSource ds = (DataSource)AppUtil.getApplicationContext().getBean("setupDataSource");
    con = ds.getConnection();
    
    // execute SQL query
    if(!con.isClosed()) {
        PreparedStatement stmt = con.prepareStatement("SELECT createdBy from app_fd_#appDef.appId#_pd where c_status = 'Approved'");
        ResultSet rs = stmt.executeQuery();
        while (rs.next()) {
            String user = rs.getObject("createdBy");
            assignees.remove(user);
        }
    }
} catch(Exception e) {
    LogUtil.error("Participant Mapping", e, "Error loading user data in participant mapping");
} finally {
    //always close the connection after used
    try {
        if(con != null) {
            con.close();
        }
    } catch(SQLException e) {/* ignored */}
}

return assignees;