Creating New Tables
All tables within a database must be created at some point in time...let's
see how we would create the Orders table:
CREATE TABLE ORDERS
(OWNERID INTEGER NOT NULL,
ITEMDESIRED CHAR(40) NOT NULL);
This statement gives the table name and tells the DBMS about each column
in the table. Please note that this statement uses generic
data types, and that the data types might be different, depending on what
DBMS you are using. As usual, check local listings. Some common generic
data types are:
- Char(x) - A column of characters, where x is a number designating the
maximum number of characters allowed (maximum length) in the column.
- Integer - A column of whole numbers, positive or negative.
- Decimal(x, y) - A column of decimal numbers, where x is the maximum
length in digits of the decimal numbers in this column, and y is the maximum
number of digits allowed after the decimal point. The maximum (4,2) number
would be 99.99.
- Date - A date column in a DBMS-specific format.
- Logical - A column that can hold only two values: TRUE or FALSE.
