Question

I have the following mysql query:

SELECT sku, quantity, inventory.isbn13, author, title, pub_date, binding, 
      defect.defect, source, location from inventory
      LEFT JOIN location ON inventory.location_id = location.location_id
      LEFT JOIN source ON inventory.source_id = source.source_id
      LEFT JOIN book ON inventory.isbn13 = book.isbn13
      LEFT JOIN defect ON inventory.defect_id = defect.defect_id
      LEFT JOIN book_condition ON book_condition.condition_id = defect.condition_id
      WHERE quantity > '0' and location.location_id >= '986' and location.location_id <= '989'
      ORDER BY inventory.location_id, sku

Which works perfectly, but now I need to show a total number of books for each location id. For example location_id 986 has 17 books, location_id 987 has 34 books etc.
do I need to run a second query to get this information or is there a way to do this in the query I have?
Thanks
Jim

Answer 1

here you go:

SELECT
    sku, 
    quantity, 
    inventory.isbn13, 
    author, 
    title, 
    pub_date, 
    binding, 
    defect.defect, 
    source, 
    location,
    t.cnt
FROM 
    inventory i
        INNER JOIN 
            (
            SELECT
                inventory.location_id,
                COUNT(book.isbn13) as `cnt`
            FROM inventory
                  LEFT JOIN book ON inventory.isbn13 = book.isbn13
            GROUP BY inventory.location_id
            ) t ON t.location_id = i.location_id
        INNER JOIN location l       ON i.location_id = l.location_id
        LEFT JOIN source            ON i.source_id = source.source_id
        LEFT JOIN defect            ON i.defect_id = defect.defect_id
        LEFT JOIN book_condition    ON book_condition.condition_id = defect.condition_id
WHERE 
    i.quantity > '0' 
AND l.location_id >= '986' 
AND l.location_id <= '989'