text: DROP TABLE categoriesc if exists;
  CREATE TABLE categories (
  	id int not null auto_increment 	primary key,
  	category_name char(100),
  	CONSTRAINT uc_category_name UNIQUE (category_name)
  );
  
  DROP TABLE suppliers if exists;
  CREATE TABLE suppliers (
  	id int not null auto_increment primary key,
      suppliers_name char(100),
      CONSTRAINT uc_suppliers_name UNIQUE (suppliers_name)
  );
  
  DROP TABLE products if exist;
  CREATE TABLE products (
  	id int not null auto_increment   primary key,
      product_name char(100),
      category_id int not null,
      CONSTRAINT uc_product_name  UNIQUE (product_name),
      foreign key (category_id) references categories(id)
  );
  
  
  
  DROP TABLE sales if exist;
  CREATE TABLE sales_table (
  	id int not null auto_increment primary key,
      price int not null,
      qty int,
      sales_date date ,
      product_id int,
      foreign key (product_id) references products(id)
  );
  
  DROP TABLE if exists purchases;
  CREATE TABLE purchases (
    id int not null auto_increment primary key,
  	product_id int,
  	supplier_id int,
  	purchases_date date,
  	qty int,
  	price decimal,
  	foreign key(product_id) references products(id),
  	foreign key(supplier_id) references suppliers(id)
  );
  
  DROP TABLE if exist UserRoles;
  CREATE TABLE UserRoles (
  	 id int not null auto_increment primary key,
  	 username varchar(100),
  	 password varchar(100),
  	 user_roles varchar(100)
  	
  );
  