Defining Primary Keys : Primary Key « Key « SQL / MySQL






Defining Primary Keys

     
mysql>
mysql> CREATE TABLE Orders
    -> (
    ->     OrderID SMALLINT UNSIGNED NOT NULL PRIMARY KEY,
    ->     ModelID SMALLINT UNSIGNED NOT NULL,
    ->     ModelDescrip VARCHAR(40)
    -> );
Query OK, 0 rows affected (0.01 sec)

mysql>
mysql>
mysql> drop table Orders;
Query OK, 0 rows affected (0.00 sec)

   
    
    
    
    
  








Related examples in the same category

1.Setting a Primary Key 1
2.Setting a Primary Key 2
3.Setting a Primary Key 3
4.Define and use primary key
5.Alter table to Add an PRIMARY KEY
6.Another way to enforce uniqueness is to add a UNIQUE index rather than a PRIMARY KEY to a table.
7.To drop an index that is not a PRIMARY KEY, you must specify the index name.
8.Adding primary key for not null column
9.Use a PRIMARY KEY constraint
10.If you were creating a primary key on more than one column, you would include both of those column names in th
11.Two ways to declare primary key when creating the table
12.Create a table t that contains an id column that's NOT NULL and declared as a primary key by means of a PRIMAR
13.A primary key on a column can be created by replacing PRIMARY KEY with UNIQUE in the table definition, provide
14.Add PRIMARY KEY or UNIQUE directly to the end of the column definition.
15.Create a primary key on the last_name and first_name columns using a PRIMARY KEY clause
16.Create a multiple-column primary key using UNIQUE, if the columns are declared NOT NULL
17.Using three column as the primary key
18.Drop primary key