Guruh talabasi Abdig’opporov javoxir Mysql 1-2-amaliy ishlar

FROM products_suppliers
JOIN products ON products_suppliers.productID = products.productID
JOIN suppliers ON products_suppliers.supplierID = suppliers.supplierID
WHERE price < 0.6;
+--------------+-------+---------------+
| Product Name | price | Supplier Name |
+--------------+-------+---------------+
| Pencil 3B | 0.52 | ABC Traders |
| Pencil 3B | 0.52 | QQ Corp |
| Pencil 6B | 0.47 | XYZ Company |
+--------------+-------+---------------+

-- Define aliases for tablenames too

mysql> SELECT p.name AS `Product Name`, s.name AS `Supplier Name`
FROM products_suppliers AS ps
JOIN products AS p ON ps.productID = p.productID
JOIN suppliers AS s ON ps.supplierID = s.supplierID
WHERE p.name = 'Pencil 3B';
+--------------+---------------+
| Product Name | Supplier Name |
+--------------+---------------+
| Pencil 3B | ABC Traders |
| Pencil 3B | QQ Corp |
+--------------+---------------+
-- Using WHERE clause to join (legacy and not recommended)
mysql> SELECT p.name AS `Product Name`, s.name AS `Supplier Name`
FROM products AS p, products_suppliers AS ps, suppliers AS s
WHERE p.productID = ps.productID
AND ps.supplierID = s.supplierID
AND s.name = 'ABC Traders';
+--------------+---------------+
| Product Name | Supplier Name |
+--------------+---------------+
| Pencil 3B | ABC Traders |
| Pencil 4B | ABC Traders |
| Pencil 5B | ABC Traders |
+--------------+---------------+
The database diagram is as follows. Both products and suppliers tables exhibit a one-to-many relationship to the junction table. The many-to-many relationship is supported via the junction table.

3.3 One-to-one Relationship
Suppose that some products have optional data (e.g., photo, comment). Instead of keeping these optional data in the products table, it is more efficient to create another table called product_details, and link it to products with a one-to-one relationship, as illustrated.

mysql> CREATE TABLE product_details (