Complex codeigniter user search query

问题

I have 3 tables user, profile and location. The structure of these tables are:

user table

user_id | email | pass | activated | banned

profile table

user_id | name | birthday | picture | gender | last_active

location table

user_id | city | country | latitude | longitude

Now here are search conditions:

User must be activated(1) to appear in search result.
User must not be banned(0).
Search results must be nearby location according to latitude and longitude.
search result must order by last active.

To display a search I will need user name, picture, city and country, age, gender and offline/online status.

I have a query to order by location:

SELECT 
    latitude, longitude, 
    SQRT( POW( 69.1 * ( latitude - 52.58 ) , 2 ) + POW( 69.1 * ( - 1.12 - longitude ) * COS( latitude / 57.3 ) , 2 ) ) AS distance
FROM 
    location 
ORDER BY 
    distance

Can anyone contribute to build a codeignitor query for these conditions?

回答1:

you could try build around this query

select l.latitude, l.longitude, 
SQRT( POW( 69.1 * ( l.latitude - 52.58 ) , 2 ) +
POW( 69.1 * ( - 1.12 - l.longitude ) * COS( l.latitude / 57.3 ) , 2 ) ) as distance
from user as u
left join profile as p
on p.user_id = u.id
left join location as l
on l.user_id = u.id
where u.activated=1 and u.banned=0
order by distance desc

May I suggest you lookup using foreign key constraints in mysql

回答2:

There are a number of other optmizations depending on how accurate you need to be and how fast you need it. I won't show you how to do that right here, but this is the basic codeIgniter query for what you asked:

$max_distance = 20;

$this->db
   ->select('*') // Change this to only the fields you need...
   ->select('SQRT( POW( 69.1 * ( latitude - 52.58 ) , 2 ) + POW( 69.1 * ( - 1.12 - longitude ) * COS( latitude / 57.3 ) , 2 ) ) AS distance')
   ->from('user')
   ->where('user.active', 1)
   ->where('user.banned !=', 0)
   ->where('distance <', $max_distance)
   ->join('location','location.user_id=user.user_id')
   ->join('profile','profile.user_id=user.user_id')
   ->order_by('last_active','desc')
   ->get();

Please note that distance calculation become slow as soon as you have hundreds of thousands of records. The most obvious optmization is to first limit the query with a box to cut down on having to calculate the distance for rows that are nowhere near, and then do the radius within that.

来源：https://stackoverflow.com/questions/8601148/complex-codeigniter-user-search-query

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php

mysql

codeigniter