Nested queries using wpdb - mysql

Question

Im trying to display a few rows of data for each <h3><?php echo $name; ?></h3> item that appears in the loop.
With the current code it only shows one row for each item <h3><?php echo $name; ?></h3>
I have this in my functions.php file
$newdb = new wpdb('login', 'pass', 'db', 'host');
<?php $result=$newdb->get_results('select tbl1.name, tbl2.col1, tbl2.col2, tbl2.col3 from tbl1, tbl2 where tbl1.name=tbl2.tbl1_name');
$names=array();
foreach($result as $row): ?>
<?php $names[$row->name][]=$row;
endforeach; ?>
<?php foreach($names as $name=>$info): ?>
<h3><?php echo $name; ?></h3>
<table>
<tr><th>col1</th><th>col2</th><th>col3</th></tr>
<?php foreach($info as $n):?>
<tr>
<td><?php echo $n->col1; ?></td>
<td><?php echo $n->col2; ?></td>
<td><?php echo $n->col3; ?></td>
</tr>
<?php endforeach; ?>
</table>
<?php endforeach; ?>
So the loop displays the heading followed by a few rows of records, not just one.
<h2>Name</h2>
<table>
<tr><th>col1</th><th>col2</th><th>col3</th></tr>
col1-value1 col2-value1 col3-value1
col1-value2 col1-value2 col1-value2
etc.
</table>
<h2>Name</h2>
<table>
<tr><th>col1</th><th>col2</th><th>col3</th></tr>
col1-value1 col2-value1 col3-value1
col1-value2 col1-value2 col1-value2
etc.
</table>
<h2>Name</h2>
<table>
<tr><th>col1</th><th>col2</th><th>col3</th></tr>
col1-value1 col2-value1 col3-value1
col1-value2 col2-value2 col3-value2
etc.
</table>
.....`

Answer 1

It's possible using your idea but you can do it using one query like
global $wpdb;
$result=$wpdb->get_results('select a.col, b.col1, b.col2, b.col3 from a,b where a.col=b.col5');
Assume that you have tbl1 table and it has a name field and tbl2 table and it has a field for example tbl1_name which has the name value of tbl1 name field and other fields, (with no duplicates) so you can join both tables like
$result=$wpdb->get_results('select tbl1.name, tbl2.col1, tbl2.col2, tbl2.col3 from tbl1, tbl2 where tbl1.name=tbl2.tbl1_name');
$names=array();
foreach($result as $row): ?>
$names[$row->name][]=$row;
<?php endforeach; ?>
foreach($names as $name=>$info):
echo $name;
?><table><?php
foreach($info as $n):
?>
<tr>
<td><?php echo $n->col1; ?></td>
<td><?php echo $n->col2; ?></td>
<td><?php echo $n->col3; ?></td>
</tr>
<?php
<?php endforeach; ?>
?></table><?php
<?php endforeach; ?>
Also remember $wpdb is a global object and available through the template files so you dont need to use new to make an instanse, just use global keyword as I wrote in my answer.
Class Reference/wpdb and sql join and this one.