我需要做些什么来更正此SQL语句

我有以下表格：

1. products-包含库存中的产品
2. suppliers-包含供应商详细信息
3. product_category-包含产品类别的名称
4. product_suppliers-包含产品和供应商之间的关系

这里重要的一个可能是product_suppliers，所以这里是列：

id //(auto-increment)  
prod_id //(id of product)  
sup_id //(id of supplier)  
preferred //(1 if it's the preferred supplier for that product - 0 if not)  
cost_per_outer //(this suppliers price for this item)  
qty_in_outer //(the number in a box)  

在存储产品详细信息的product表中，还具有用于stock_level和reorder_level的字段。当前者少于后者时，应将该产品包括在重新订购的列表中。

我正在尝试为列表构建查询，但运行不太正常。

我有4个项目符合重新订购的条件，影响了两个供应商。每个供应商应该有两个项目，但目前它只检索第一个供应商的结果。

我使用的是MySQL和PHP。

我运行了以下查询，以便深入了解数据库中的实际数据：

mysql> SELECT
    ->         p.prod_id,
    ->         AES_DECRYPT(p.alt_id, 'MW4KQLg1Irfo3Xz7Nxht')                         AS sku,
    ->         AES_DECRYPT(p.prod_name, 'MW4KQLg1Irfo3Xz7Nxht')                      AS prod_name,
    ->         AES_DECRYPT(p.prod_type, 'MW4KQLg1Irfo3Xz7Nxht')                    AS prod_type,
    ->         AES_DECRYPT(p.stock_level, 'MW4KQLg1Irfo3Xz7Nxht')                    AS stock_level,
    ->         AES_DECRYPT(p.reorder_level, 'MW4KQLg1Irfo3Xz7Nxht')            AS reorder_level,
    ->         AES_DECRYPT(c.category_name, 'MW4KQLg1Irfo3Xz7Nxht')            AS category_name,
    ->         ps.sup_id,
    ->         ps.preferred
    -> FROM
    ->         products p
    -> INNER JOIN
    ->         product_category c
    ->   ON
    ->         p.category_id = c.category_id
    -> INNER JOIN
    ->         product_supplier ps
    ->   ON
    ->         p.prod_id = ps.prod_id
    -> INNER JOIN
    ->         suppliers s
    ->   ON
    ->         ps.sup_id = s.supplier_id
    -> ORDER BY
    ->         ps.sup_id;
+---------+------+-----------------+-----------+-------------+---------------+---------------+--------+-----------+
| prod_id | sku  | prod_name       | prod_type | stock_level | reorder_level | category_name | sup_id | preferred |
+---------+------+-----------------+-----------+-------------+---------------+---------------+--------+-----------+
|       7 | 7    | Term Block      | 1         | 3           | 5             | Electrical    |      2 |         1 |
|       5 | 5    | Electrical Tape | 1         | 12          | 20            | Electrical    |      2 |         1 |
|       6 | 6    | BlowGas         | 1         | 6           | 15            | Plumbing      |     12 |         1 |
|       1 | 1    | PTFE Tape       | 1         | 9           | 10            | Plumbing      |     12 |         1 |
+---------+------+-----------------+-----------+-------------+---------------+---------------+--------+-----------+

以下是对列表的查询，结果只显示了我所期望的四个项目中的两个：

mysql> SELECT
    ->         p.prod_id,
    ->         AES_DECRYPT(p.alt_id, 'MW4KQLg1Irfo3Xz7Nxht')                         AS sku,
    ->         AES_DECRYPT(p.prod_name, 'MW4KQLg1Irfo3Xz7Nxht')                AS prod_name,
    ->         AES_DECRYPT(p.prod_desc, 'MW4KQLg1Irfo3Xz7Nxht')                 AS prod_desc,
    ->         AES_DECRYPT(p.stock_level, 'MW4KQLg1Irfo3Xz7Nxht')                AS stock_level,
    ->         AES_DECRYPT(p.reorder_level, 'MW4KQLg1Irfo3Xz7Nxht')             AS reorder_level,
    ->         AES_DECRYPT(p.reorder_qty, 'MW4KQLg1Irfo3Xz7Nxht')               AS reorder_qty,
    ->         p.vat_exempt,
    ->         AES_DECRYPT(p.lastorderdate, 'MW4KQLg1Irfo3Xz7Nxht')            AS lastorderdate,
    ->         AES_DECRYPT(p.lastorderqty, 'MW4KQLg1Irfo3Xz7Nxht')               AS lastorderqty,
    ->         AES_DECRYPT(c.category_name, 'MW4KQLg1Irfo3Xz7Nxht')          AS category_name,
    ->         ps.sup_id
    -> FROM
    ->         products p
    -> INNER JOIN
    ->         product_category c
    ->   ON
    ->         p.category_id = c.category_id
    -> INNER JOIN
    ->         product_supplier ps
    ->   ON
    ->         p.prod_id = ps.prod_id
    -> INNER JOIN
    ->         suppliers s
    ->   ON
    ->         ps.sup_id = s.supplier_id
    -> WHERE
    ->         AES_DECRYPT(p.prod_type, 'MW4KQLg1Irfo3Xz7Nxht') = 1
    ->   AND
    ->           AES_DECRYPT(p.stock_level, 'MW4KQLg1Irfo3Xz7Nxht') <= AES_DECRYPT(p.reorder_level, 'MW4KQLg1Irfo3Xz7Nxht')
    ->   AND
    ->           ps.preferred = 1
    -> ORDER BY
    ->         ps.sup_id;
+---------+------+-----------------+------------------------+-------------+---------------+-------------+------------+---------------+--------------+---------------+--------+
| prod_id | sku  | prod_name       | prod_desc              | stock_level | reorder_level | reorder_qty | vat_exempt | lastorderdate | lastorderqty | category_name | sup_id |
+---------+------+-----------------+------------------------+-------------+---------------+-------------+------------+---------------+--------------+---------------+--------+
|       7 | 7    | Term Block      | Nylon connector block. | 3           | 5             | 20          |          0 | NULL          | NULL         | Electrical    |      2 |
|       5 | 5    | Electrical Tape | Black                  | 12          | 20            | 100         |          0 | NULL          | NULL         | Electrical    |      2 |
+---------+------+-----------------+------------------------+-------------+---------------+-------------+------------+---------------+--------------+---------------+--------+