Add category and recipe_category tables to database schema

Author: Vianpyro

database.sql

@@ -180,3 +180,16 @@ CREATE OR REPLACE TABLE recipe_rating (
     FOREIGN KEY (recipe_id) REFERENCES recipe (recipe_id) ON DELETE CASCADE,
     UNIQUE (person_id, recipe_id)
 ) ENGINE = InnoDB;
+
+CREATE OR REPLACE TABLE category (
+    category_id INT AUTO_INCREMENT PRIMARY KEY,
+    category_name VARCHAR(50) UNIQUE
+) ENGINE = InnoDB;
+
+CREATE OR REPLACE TABLE recipe_category (
+    recipe_id INT,
+    category_id INT,
+    PRIMARY KEY (recipe_id, category_id),
+    FOREIGN KEY (recipe_id) REFERENCES recipe (recipe_id) ON DELETE CASCADE,
+    FOREIGN KEY (category_id) REFERENCES category (category_id) ON DELETE CASCADE
+) ENGINE = InnoDB;