Allow resetting offset and limit

[bpolaszek]

Hello @shadowhand,

I hope you're doing well.

I've figured out the current SelectQuery does not allow to reset limit() and offset() (their definitions do not allow null values). The only way to reset them is to set them to 0, but here's what it does with an example use case:

require_once __DIR__ . '/vendor/autoload.php';

use Latitude\QueryBuilder\SelectQuery;
use Latitude\QueryBuilder\Expression as e;
use Latitude\QueryBuilder\Conditions as c;

$query = SelectQuery::make();
$query->from('my_table');
$query->orderBy(['id', 'desc']);
$query->where(
    c::make('foo = bar')
);
$query->offset(50);
$query->limit(10);

$count = clone $query; // Create a COUNT(*) query for pagination, with the same WHERE conditions
$count->columns(e::make('COUNT(*)'));
$count->limit(0); // Reset limit to count all rows
$count->offset(0); // Reset offset to count all rows

print $query->sql();
print PHP_EOL;
print $count->sql();

Here's what it currently produces:

SELECT * FROM my_table WHERE foo = bar ORDER BY id DESC LIMIT 10 OFFSET 50
SELECT COUNT(*) FROM my_table WHERE foo = bar ORDER BY id DESC OFFSET 0

The 2nd statement is not valid SQL (at least, MySQL kicks me out) because the intended behaviour was not to set the limit and offset to 0 but to remove these parts from the query.

The solution

With this PR null values will be allowed:

$count->limit(null);
$count->offset(null);

Now outputs:

SELECT * FROM my_table WHERE foo = bar ORDER BY id DESC LIMIT 10 OFFSET 50
SELECT COUNT(*) FROM my_table WHERE foo = bar ORDER BY id DESC

BC breaks

$count->limit(0);
$count->offset(0);

Will now output:

SELECT * FROM my_table WHERE date_added BETWEEN ? and ? ORDER BY id DESC LIMIT 10 OFFSET 50
SELECT COUNT(*) FROM my_table WHERE date_added BETWEEN ? and ? ORDER BY  LIMIT 0 OFFSET 0

But at least this is now valid SQL.

[shadowhand]

Works for me, thanks!

[bpolaszek]

Thanks @shadowhand !

[shadowhand]

Released in version 2.2.0