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cakephp-3.0cakephp-3.4

How to implement CASE WHEN under ORDER BY using CakePHP 3


The SQL:

SELECT Students.name AS `Students__name`, Students.role AS 
`Students__role` FROM students Students
WHERE id IN 
  (1053,1056,733,734,735,736,737,739,748) 
  AND name LIKE '%v%' ORDER BY 
CASE 
  WHEN name LIKE '%v' THEN 1
  WHEN name LIKE 'v%' THEN 2
  WHEN name LIKE '%v%' THEN 3
  ELSE 4
END

So far:

$SInfo = TableRegistry::get('Students')->find()
->where(function($ex) use ($sArray, $sName) {
    $ex->in('id', $sArray);
    $ex->like('name', '%'.$sName.'%');
    return $ex;
});
->select(['name', 'role']);

order() function does not take ExpressionQuery. I have tried using $ex->addCase() under order but that didn't work either.


Solution

  • If you want to use a CASE statement in the order() method, you can write it like this:

    $SInfo = TableRegistry::get('Students')->find()
        ->select(['name', 'role'])
        ->where(function($ex) use ($sArray, $sName) {
            $ex->in('id', $sArray);
            $ex->like('name', '%' . $sName . '%');
            return $ex; 
        })
        ->order('(CASE WHEN name LIKE \'%v\' then 1 when name LIKE \'v%\' then 2 when name LIKE \'%v%\' then 3 else 4 END)');
    

    Edit: As suggested in the comment of this answer (thanks @ndm) you should use corresponding CASE expressions instead:

    $SInfo = TableRegistry::get('Students')->find()
    ->select(['name', 'role'])
    ->where(function($ex) use ($sArray, $sName) {
        $ex->in('id', $sArray);
        $ex->like('name', '%' . $sName . '%');
        return $ex; 
    })
    ->order(function ($exp, $q) {
        return $exp->addCase(
            [
                $q->newExpr()->like('name', '%v'),
                $q->newExpr()->like('name', 'v%'),
                $q->newExpr()->like('name', '%v%'),
            ],
            [1,  2, 3, 4], # values matching conditions
            ['integer', 'integer', 'integer', 'integer'] # type of each value
        );
    });