Nested While Loops

I am building an xml file busing java/jsp.  The data is pulled from a database.  The database has two tables with a standard foriegn key relationship.  

Table A
PK id
data column1
data column2

Table B
PK id2
PK id  (FK) to table A  (this is not unique in this table, of course)
data column3
data column4

So the id column from Table A can have multilpe values from table B.

I want my xml document to have something along the lines of this structure, excluding xml tags.

<tag1 ...   <%=result.getString(data column1)%> />
<tag2...   <%=result.getString(data column 2)%> />
<tag3... <%=result.getString(data column 3)%> />
<tag4... <%=result.getString(data column 4)%> />
<tag3... <%=result.getString(data column 3)%> />
<tag4... <%=result.getString(data column 4)%> />

how do I set this up? In my current code, it repeats tags for data column1 and 2 for every column3 and 4.  Is there any way to do a nested while loop or something similar

<%@page contentType="text/xml" language="java" import="java.sql.*, java.io.*, java.util.*"%>
<?xml version="1.0" encoding="UTF-8" ?>
<batch>
    <controls>
<%
.......
    Connection conn = DriverManager.getConnection(url, user, password);
    java.sql.Statement stmt = conn.createStatement();
ResultSet result = stmt.executeQuery("SELECT * FROM Table_A ");
    
    while (result.next())
    {
%>
               <control local_id= "<%=result.getString("data_column1")%>">
                <link type= "in" ref= "<%=result.getString("data_column2")%>" />
<%
        String controlid = result.getString("data_column1");
        ResultSet result2 = stmt.executeQuery("SELECT * FROM psc_atpid_evidence WHERE CONTROL_ID = '" + controlid +"'");
        while (result2.next())
        {
%>
                <attr name= "mref" value = "<%=result2.getString("data_column3")%>"  />
                <attr name= "Method" value = "<%=result2.getString("data_column4")%>" />
           
<%
}
%>
 </control>
<%
}
conn.close();
%>
    </controls>
</batch>

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