Question

I, I would like to make a query and sorting my members in a special way… Could someone help ?
Here’s the problem.
I would like to select members in my table using a special sort order.
The profile fields values are stored in a table wp_bp_xprofile_data like this :

   id   | field_id | user_id |     value
--------+----------+---------+----------

For example, I have 3 fields

• NICKNAME (field_id = 1)
• FIRSTNAME (field_id = 2)
• LASTNAME (field_id = 3)

The table rows will look like this :

   id   | field_id | user_id |     value
--------+----------+---------+----------
  2544       1          100       fib
  2545       2          100       john
  2546       3          100       arenzich

  2547       1          200       dog
  2548       2          200       rick
  2549       3          200       zarenburg

  2550       1          300       fox
  2551       2          300       frank
  2552       3          300       arenzich

I’ve got this query to sort them using one field, for example to sort them by nickname alphabetically :

SELECT *
FROM wp_bp_xprofile_data u WHERE u.field_id = 1 ORDER BY u.value ASC

So they will be sorted like this : dog(200),fib(100), then fox(300).
Now, I would like to sort them not one but several fields (firstname and lastname; to differenciate people with same lastname) so that the query returns the users in this order :

frank arenzich (300), john arenzich (100), frank arenzich (200).

Any idea for doing this ?

Thanks A LOT !!!

Answer 1

This will probably need to be done by first pivoting this into a proper table by column, and then ordering that on multiple columns.
Note: this will not produce output in the same format as your original table, but is arguably a lot more flexible and useful as it combines all information about each user_id into a single row.

/* A column-wise pivot of NICKNAME, FIRSTNAME, LASTNAME */
SELECT
  user_id,
  MAX(CASE WHEN field_id = 1 THEN value ELSE null END) AS NICKNAME,
  MAX(CASE WHEN field_id = 2 THEN value ELSE null END) AS FIRSTNAME,
  MAX(CASE WHEN field_id = 3 THEN value ELSE null END) AS LASTNAME
FROM wp_bp_xprofile_data
GROUP BY user_id
/* Include the HAVING if you only want those who have both first & last names specified */
HAVING 
  FIRSTNAME IS NOT NULL 
  AND LASTNAME IS NOT NULL
/* Pivoted columns can then be treated in the ORDER BY */
ORDER BY 
  FIRSTNAME,
  LASTNAME

Here is a demonstration…

It looks like this is a WordPress table, so you may not be in a position to change its structure. But if you do have the option of modifying it, I would recommend changing the structure to resemble the pivot’s output to begin with.