使用CodeIgniter在MySQL中区分大小写的LIKE和WHERE子句匹配

Question

My database/table/column collation is set to *_ci mean case insensitive. What I want is to write case sensitive query on run time using CodeIgniter for LIKE and WHERE clause. I tried an approach something like this

$this->db->where("fieldname LIKE BINARY 'value'", NULL, true);

But this approach is not working with LIKE clause

$this->db->like("fieldname LIKE BINARY 'value'", NULL);

Any type of help will greatly appreciated!

Answer 1

How about this

$value = "abdulla";
$query = $this->db->query("SELECT * FROM table WHERE fieldname1 Like '%$value%' OR fieldname2 Like '%$value%'");
$result = $query->result_array();

actually $this->db->like(); act as WHERE ??? LIKE '???' WHERE ??? LIKE '???'

For example

$this->db->like('name', 'abdulla');     
// Produces: WHERE name LIKE '%abdulla%'

Answer 2

You can do it with get() method like:

$result = $this->db
    ->where('fieldname like binary "value"', NULL, FALSE)
    ->get('table')
    ->result();

Answer 3

So you can try it like as

$this->db->like('fieldname', 'value');

You can control the wildcard (%) as per your needs you can use 'before' , 'after' and 'both' . If you don't need the wildcard then you can simply pass the third parameter as none .

Check the DOCS

Answer 4

Well well well ...

After searching around and hammering my head I finally solved this issue! First of all I have to set the collation of table/column to *_cs, after that if I need case sensitive matching I have to run simple

$this->db->where('field', 'value');

or

$this->db->like('field', 'value');

But if you want case insensitive matching than use

$this->db->where("LOWER('field')", strtolower('value'), false);

$this->db->where() accepts an optional third parameter. If you set it to FALSE, CodeIgniter will not try to protect your field or table names with backticks.

or

$this->db->like("LOWER('field')", strtolower('value'));

Remember CodeIgniter follows the standard collation of your MySQL database, there is no built in function is available in CI 2.x to over write default database collation. So if your column/table collation is set to *_ci (case insensitive) CI will consider abc = aBc but if your collation is set as *_cs it will consider abc != aBc