A key is a set of attributes that is irreducibly unique and non-nullable within a table.
This example is taken from w3schools. CREATE TABLE Persons ( P_Id int NOT NULL, LastName varchar(255) NOT NULL, FirstName …
database-design relational-database primary-key ddl database-tableI have a table in Oracle which has following schema: City_ID Name State Country BuildTime Time When I declared …
sql oracle primary-keyI have to two tables namely employees_ce and employees_sn under the database employees. They both have their respective …
sql foreign-keys primary-keyWe are using UUID as primary key for out oracle DB, and trying to determine an appropriate max character length …
oracle primary-key uuidHere is a table in MySQL 5.3.X+ db: CREATE TABLE members` ( `id` int(11) UNSIGNED NOT NULL AUTO_INCREMENT, `memberid` VARCHAR( 30 ) …
mysql primary-key auto-increment mysql-error-1075create table d(id numeric(1), code varchar(2)) After I create the above table how can I add a composite primary …
sql sql-server-2005 foreign-keys primary-keyFor some reason, people in the past have inserted data without using sequence.NEXTVAL. So when I go to use …
sql oracle oracle10g primary-key sequenceI am using MySQL 5.1.56, MyISAM. My table looks like this: CREATE TABLE IF NOT EXISTS `my_table` ( `number` int(11) NOT …
mysql primary-key mysql-error-1062 duplicatesI have a database with 3 columns: id, name, somethingelse This table has no index set and i am getting "No …
mysql sql indexing primary-keyCan anyone explain about the purpose of PRIMARY KEY, UNIQUE KEY and KEY, if it is put together in a …
mysql sql-server primary-key unique-key