How can I group WHERE clauses in CodeIgniter for complex queries?

Active Record WHERE Clauses in Codeigniter: Grouping for Complex Queries

When using Active Records in Codeigniter, you may encounter a situation where you need to group WHERE clauses for complex queries. This can be particularly useful when generating dynamic SQL queries based on input parameters.

To solve this problem in Codeigniter versions 3 and 4, you can utilize the group_start() and group_end() methods.

Codeigniter 3

$this->db->select()
  ->from('users')
  ->where('name !=', 'Joe')
  ->group_start() // Open bracket
    ->where('age <', 69)
    ->or_where('id <', $id)
  ->group_end(); // Close bracket

Codeigniter 4

$builder->select('*')
  ->from('users')
  ->where('name !=', 'Joe')
  ->groupStart()
    ->where('age <', 69)
    ->orWhere('id <', $id)
  ->groupEnd();

By using these methods, you can effectively group WHERE clauses and ensure the correct operator precedence, even when using multiple OR clauses.

As an example, consider the following scenario where you want to dynamically generate a query based on price ranges:

if ($price_range) {
  $price_array = explode('.', $price_range);
  for ($i = 0; $i < count($price_array); $i++) {
    if ($i == 0) {
      $this->db->where('places.price_range', $price_array[$i]);
    } else {
      $this->db->or_where('places.price_range', $price_array[$i]);
    }
  }
}

In this example, the problem lies with the use of or_where(), which could lead to unexpected results due to operator precedence. By using group_start() and group_end(), you can group the OR clauses and ensure they are evaluated correctly.

The above is the detailed content of How can I group WHERE clauses in CodeIgniter for complex queries?. For more information, please follow other related articles on the PHP Chinese website!