问题

im trying to build a location based event search in PHP + MySQL (Using Laravel and its Eloquent ORM)

This is the query I am using:

select 
    events.*, 
    ( 3959 * acos( cos( radians(50.5) ) * cos( radians( addresses.latitude ) ) * cos( radians( addresses.longitude ) - radians(9.50) ) + sin( radians(50.5) ) * sin( radians( addresses.latitude ) ) ) ) AS distance

 from 
    `events` inner join `addresses` on `events`.`address_id` = `addresses`.`id`
 having 
    `distance` <= 10 
 order by 
    `id` desc limit 15 offset 0

Im wondering why this error pops up, even though the distance column is in the "select statement".

"SQLSTATE[42S22]: Column not found: 1054 Unknown column 'distance' in 'having clause' (SQL: select count(*) as aggregate from `events` inner join `addresses` on `events`.`address_id` = `addresses`.`id` having `distance` <= 10 order by `id` desc)"

This is the PHP Code I use to add the scope to the base query:

    $selectDistance =
        '( 3959 * acos( cos( radians(' . $latitude . ') ) ' .
        '* cos( radians( addresses.latitude ) ) ' .
        '* cos( radians( addresses.longitude ) - radians(' . $longitude . ') ) ' .
        '+ sin( radians(' . $latitude . ') ) ' .
        '* sin( radians( addresses.latitude ) ) ) ) AS distance';

    $query->select(DB::raw('events.*, ' . $selectDistance));
    $query->join('addresses', 'events.address_id', '=', 'addresses.id');
    $query->having('distance', '<=', $km);

Thank you very much :)

回答1:

From the error message:

"SQLSTATE[42S22]: Column not found: 1054 Unknown column 'distance' in 'having clause' (SQL: select count(*) as aggregate from events inner join addresses on events.address_id = addresses.id having distance <= 10 order by id desc)"

We can get the following

SQL:

select count(*) as aggregate 
from `events` inner join `addresses` on `events`.`address_id` = `addresses`.`id` 
having `distance` <= 10 
order by `id` desc

distance is not in the select list.

回答2:

The HAVING clause was introduced to SQL because we cannot use aggregate functions with WHERE keyword. According to your query there is no aggregate function within the SELECT statement or the HAVING clause. Therefore try to change

having 
    `distance` <= 10

where
    `distance` <= 10

The HAVING clause should be used in below format.

HAVING aggregate_function(column_name) operator value

Where operator can be =, >, < , <=, ect....

Furthermore your PHP code also need to be changed accordingly.

Below SQL tutorial link might help you to better understand the use of HAVING clause in SQL.

http://www.w3schools.com/sql/sql_having.asp

回答3:

You can try something like that

$selectDistance =
    '( 3959 * acos( cos( radians(' . $latitude . ') ) ' .
    '* cos( radians( addresses.latitude ) ) ' .
    '* cos( radians( addresses.longitude ) - radians(' . $longitude . ') ) ' .
    '+ sin( radians(' . $latitude . ') ) ' .
    '* sin( radians( addresses.latitude ) ) ) )'; 

$query->join('addresses', 'events.address_id', '=', 'addresses.id')
      ->select(DB::raw('events.*))
      ->selectRaw("{$selectDistance} AS distance")
      ->whereRaw("{$selectDistance} < ?", 10)
      ->get();

来源：https://stackoverflow.com/questions/36236125/unknown-aggregate-column-in-having-clause

标签

php