Geek asks and answers

MySQL subquery for each record in a group

This is a more advanced continuation of an earlier question.

Here's a link to SQLFiddle to make things clearer

I need to return something like (for each location):

Ground floor
---------------
Garage
- Radiator
Kitchen
- Stove
- Refrigerator

There will be even more levels than this, but if I can start, I hope I can go further as necessary.

thank

+5
source share
3 answers

SQL , , , sub_location. location, sub_location , , .

SELECT
  location.location_name,
  sublocation.sub_location_name,
  asset.asset_name
FROM
  location
  LEFT JOIN sub_location ON location.location_key = sublocation.location_key
  LEFT JOIN assets ON sub_location.sub_location_key = assets.sub_location_key
ORDER BY
  location.location_name,
  sub_location.sub_location_name

, sub_location . .

, $rowset:

// Store location, sub_location for each loop
$current_loc = "";
$current_subloca = "";
foreach ($rowset as $row) {
  // If the location changed, print it
  if ($row['location'] != $current_loc) {
    echo $row['location_name'] . "\n";
    // Store the new one
    $current_loc = $row['location_name'];
  }
  // If the sub_location changed, print it
  if ($row['sub_location'] != $current_subloc) {
    echo $row['sub_location_name'] . "\n";
    $current_subloc = $row['sub_location_name'];
  }
  echo $row['asset_name'] . "\n";      
}
+2

:

SELECT a.name
FROM
(
    SELECT 
        CONCAT('- - - - - - - - - -> ', a.asset_name) AS name,
        CONCAT(c.location_key, c.location_name, b.sub_location_name, a.asset_name) AS orderfactor
    FROM asset a
    INNER JOIN sub_location b ON a.sub_location_key = b.sub_location_key
    INNER JOIN location c ON b.location_key = c.location_key

    UNION ALL

    SELECT 
        CONCAT('- - - - -> ', a.sub_location_name),
        CONCAT(b.location_key, b.location_name, a.sub_location_name)
    FROM sub_location a
    INNER JOIN location b ON a.location_key = b.location_key

    UNION ALL

    SELECT
        location_name,
        CONCAT(location_key, location_name)
    FROM location
) a
ORDER BY a.orderfactor

.

SQLFiddle Demo

:

Ground Floor
-----> Garage
----------> Radiator
-----> Kitchen
----------> Cooker
----------> Fridge
First Floor
-----> Bedroom
----------> Radiator
----------> Taps
Second Floor
-----> Bathroom
----------> Shower
----------> Taps
----------> Toilet
Third Floor
+2

MySQL5

SELECT L.location_name, GROUP_CONCAT(DISTINCT S.sub_location_name), GROUP_CONCAT(A.asset_name) 
FROM location L
INNER JOIN sub_location S ON L.location_key = S.location_key
INNER JOIN asset A ON A.sub_location_key = S.sub_location_key
GROUP BY S.sub_location_name ORDER BY L.location_key

http://sqlfiddle.com/#!2/db932/9

+1

More articles:


All Articles