-- Crear una base de datos llamada sql_store2 CREATE DATABASE sql_store2; -- Evitar error si ya existe CREATE DATABASE IF NOT EXISTS sql_store2;
Query OK, 1 row affected Database changed
USE sql_store2; CREATE TABLE customers ( customer_id INT PRIMARY KEY AUTO_INCREMENT, first_name VARCHAR(50) NOT NULL, points INT NOT NULL DEFAULT 0, email VARCHAR(255) NOT NULL UNIQUE );
Query OK, 0 rows affected
– Ejercicio - CreateTable 1
– opcion para evitar errores – orders depende de customers
CREATE TABLE orders ( order_id INT PRIMARY KEY, customer_id INT NOT NULL, FOREIGN KEY (customer_id) REFERENCES customers (customer_id) ON UPDATE CASCADE ON DELETE NO ACTION );
– Ejercicio - CreateTable 3
– Cambiando primery key y foreign key
ALTER TABLE orders DROP PRIMARY KEY, ADD PRIMARY KEY (order_id), DROP FOREIGN KEY orders_ibfk_1, ADD FOREIGN KEY (customer_id) REFERENCES customers (customer_id) ON UPDATE CASCADE ON DELETE NO ACTION;
Query OK, 0 rows affected Records: 0 Duplicates: 0 Warnings: 0
CREATE DATABASE tienda CHARACTER SET latin1; USE tienda; CREATE TABLE productos ( id INT AUTO_INCREMENT PRIMARY KEY, nombre VARCHAR(50) CHARACTER SET latin1, precio DECIMAL(8,2) );