
Mysql
I recently discovered a cool function in MySQL that is nice for doing group by queries where you want to return a column with a comma separated list of data to sum up totals. I learn best from examples so let’s look a 3 table example.
Products
CREATE TABLE products (
  id int(11) NOT NULL AUTO_INCREMENT,
  name varchar(255) NOT NULL,
  PRIMARY KEY (id)
)
Inventory Items
CREATE TABLE inventory_items (
  id int(11) NOT NULL AUTO_INCREMENT,
  product_id int(11) NOT NULL,
  sku varchar(255) NOT NULL,
  PRIMARY KEY (id)
)
Orders
CREATE TABLE orders (
  id SERIAL,
  inventory_item_id INTEGER NOT NULL,
  amount INTEGER NOT NULL,
  PRIMARY KEY (id)
)
                  
                  
              