ORDER BY an equal value in MySQL

Question

All, I\'ve got the following SQL query as of now:

SELECT * FROM $wpdb->posts
JOIN $wpdb->term_relationships ON $wpdb->term_relationships.object_id=$         


        

Answer 1

It is straightforward like this:

...
ORDER BY featured = 'yes'

featured = 'yes' is evaluates as boolean true or false, for items that featured = "yes" is true will come first then items that has featured = "yes" is false i.e featured = "no" come later.

Update:

You can use CASE statement in the order by clause to sort your data on a sepecific field, something like:

ORDER BY 
        CASE WHEN postmeta.meta_key = 'featured' 
             THEN meta_value = 'yes' DESC  
        END

OR:

ORDER BY ( postmeta.meta_key = 'featured' AND meta_value = 'yes') DESC

You might need to add another order by criteria in the ELSE part of the CASE statement to order the items that have meta_key = 'featured is false to order them by.

If the field metadata_key is always = "featured" then you can get rid of the case statement and use just ORDER BY meta_value = 'yes' DESC

Answer 2

SELECT ...
FROM   ...
ORDER BY (meta_key='featured' AND meta_value='yes') DESC, postid ASC;

If (meta_key='featured' AND meta_value='yes') for a row, that row will have a 1/TRUE. Otherwise, it will have a 0/FALSE. Hence, sorting descending puts the rows that have TRUE first.

Answer 3

Also, you can use MySQL function named

FIELD(HAYSTACK, value[, ...values]).

This function returns index of haystack in values (FROM 1 to n, 0 - if not found).

Example

ORDER BY FIELD(wp_postmeta.meta_key, 'featured', wp_postmeta.meta_key), 
FIELD(wp_postmeta.meta_value, 'yes', wp_postmeta.meta_value), wp_posts.post_date DESC

But, in your case, use the mathematical.coffee example. In my example you need to repeat the field name in the end of list, because if you don't - it will return 0 (zero) and elements than not in list will be first in result statement.