MySQL: CREATE TABLE ORDERS (Order_ID integer, Order_Date date, Customer_SID integer, Amount double, Primary Key (Order_ID), Foreign Key (Customer_SID) references CUSTOMER(SID)); Oracle: CREATE TABLE ORDERS (Order_ID integer primary key, Order_Date date, Customer_SID integer references CUSTOMER(SID), Amount double); SQL Server: CREATE TABLE ORDERS (Order_ID integer primary key, Order_Date datetime, Customer_SID integer references CUSTOMER(SID), Amount double); Below are… Leer más »

MySQL migration: MyISAM to InnoDB   By Keith Winston on July 18, 2005 (8:00:00 AM) The MySQL database is unique in that it offers multiple storage engines. The SQL parser and front end interfaces are separate from the storage engines, so you can choose among nine low-level table formats the one that suits your application… Leer más »

  Simply put, referential integrity means that when a record in a table refers to a corresponding record in another table, that corresponding record will exist. Look at the following: