Tutorial: Using SQL DATABASE action in CF7

This is a sql_data_1 of #__users:
sql_data_1
SELECT username FROM #__users LIMIT 2;

This is a read_data_2 of #__users from sql_data_1:
read_data_2, Where Condition
WHERE CONDITION username = {var:sql_data_1.[n].username}

This is a sql_data_3 of #__users from sql_data_1:
sql_data_3
SELECT username, name FROM #__users WHERE username IN ('{var.join[', ']:sql_data_1.[n].username}');

How to add a model in sql_data_1 to use in a table list (or other):
sql_data_4
SELECT username FROM #__users LIMIT 20;
php_5
$tmp=$this->get("sql_data_4",[]); foreach ($tmp as $key => $value) {$tmp[$key]=array('my_model'=>$value);};
$this->set("sql_data_4",$tmp);
Table_list
Data source : {var:sql_data_4}
Path: my_model.username

Enjoy!