Nested OR and AND condition with db_select [duplicate]

Question

How can I convert the following query with db_select

SELECT *
FROM 'my_table'
WHERE
(condition1 < "value1" AND ((conidition2 > "value2") OR (condition3 < "value3")))
  OR
(condition4 < "value5" AND ((condition6 < "value6") OR (condition7 < "value7")))

I am trying with

$query = db_select('mytable');

$query->condition(
          db_and()->condition("condition1","value1")
                 ->condition(
                             db_or()->condition("condition2","value2")->condition("condition3","value3")
                             ));
$query->condition(
          db_and()->condition("condition4","value4")
                 ->condition(
                             db_or()->condition("condition5","value5")->condition("condition6","value6")
                             ));

  $query_debugg = $query->__toString();
dpm($query_debugg);

issue is with the "AND" in between where is should be "OR", it is expected I know.how can I change it

Output String

SELECT 
FROM 
{mytable} mytable
WHERE ( (condition1 = :db_condition_placeholder_0) AND( (condition2 = :db_condition_placeholder_1) OR (condition3 = :db_condition_placeholder_2) ))AND( (condition4 = :db_condition_placeholder_3) AND( (condition5 = :db_condition_placeholder_4) OR (condition6 = :db_condition_placeholder_5) ))

Answer 1

In Drupal, conditions are AND by default. It's easier to use objects directly, in my opinion:

$left_condition = new DatabaseCondition('AND');
$left_condition->condition( ... ); // add what you need

$right_condition = new DatabaseCondition('AND');
$right_condition->condition( ... ); // add what you need

$condition = new DatabaseCondition('OR');
$condition->condition($left_condition);
$condition->condition($right_condition);

But you can use db_and() and db_or() if you prefer.

Answer 2

with help of question pointed by @molot I could make it work, here is the code

$query = db_select('mytable');
$db_or = db_or();
$db_or->condition(
  db_and()
    ->condition("condition1","value1")
    ->condition(
      db_or()
        ->condition("condition2","value2")
        ->condition("condition3","value3")
));
$db_or->condition(
  db_and()
    ->condition("condition4","value4")
    ->condition(
      db_or()
        ->condition("condition5","value5")
        ->condition("condition6","value6")
));
$query->condition($db_or);

$src = $query->__toString();
dpm($src);

and here is the output

SELECT 
FROM 
{mytable} mytable
WHERE (( (condition1 = :db_condition_placeholder_0) AND( (condition2 = :db_condition_placeholder_1) OR (condition3 = :db_condition_placeholder_2) ))OR( (condition4 = :db_condition_placeholder_3) AND( (condition5 = :db_condition_placeholder_4) OR (condition6 = :db_condition_placeholder_5) )))