mysql 多对多查询与来自另一个表的位置

Question

This should be trivial, but my SQL chops are still pretty weak. I have setup an intermediate table for many-to-many queries in MySQL, let's call it 'item_packs' linking the 'packs' table with the 'items' table. I want to list all the 'items' where the entered 'pack_name' matches the name in the 'packs' table.

packs table
packindex | packname (varchar) 
------------------------------
   1      |   todayspack
   2      |   anotherpack

items table
itemindex | itemname (varchar)
------------------------------
   1      |   firstitem
   2      |   anotheritem

item_packs table
   item   |   pack 
------------------------------
   1      |   2
   2      |   2

I almost have it:

SELECT c.*
FROM items c
JOIN item_packs j on j.item = c.itemindex
JOIN packs t on j.pack = t.packindex
where  j.pack= 1

It works if I enter the pack index (1) but I need to have that value come from the index in the 'packs' table where the pack name matches the entered pack name (todayspack).

Answer 1

So you want to compare the name to some string? Your query looks good, try this:

SELECT c.*
FROM items c
JOIN item_packs j on j.item = c.itemindex
JOIN packs t on j.pack = t.packindex
where  j.packname='todayspack'

Answer 2

SELECT c.*
FROM items c
JOIN item_packs j on j.item = c.itemindex
JOIN packs t on j.pack = t.packindex
where  t.packname = 'todayspack';