PHP optimizes SQL queries in foreach

describe
The data to be queried needs to be associated 3 Tables , First use the first two tables left join After querying, use foreach Query the contents of the third table . But in foreach There is too much data in it , It will be very slow and sometimes collapse

An optimization method
stay foreach Find out all the data in the third table

Code ：

# 1. Joint query of two tables 
$list = Db::query("select a.id,a.organ_name,b.basctype,b.bascidno,b.bascname,b.bascaddress from tablea a left join tableb b on a.id=b.aid where a.createtime >= '2022-06-01' ");

if($list){
    
	$new_table3_list = [];
	$table3_list = Db::query("select aid,name,tel from tablec where name is null");
	if($table3_list){
    
		foreach($table3_list as $v){
    
                    $new_table3_list[$v['aid']] = [
                        'name'=>$v['name'],
                        'tel'=>$v['tel'],
                    ];
                }
	}
	foreach($list as $key=>$val){
    
		if(!empty($new_table3_list[$val['id']])){
    
			$val['name']=$new_table3_list[$val['id']]['name'];
			$val['tel']=$new_table3_list[$val['id']]['tel'];
		}
	}
}