Structured Query Language Made Simple
Fukula Hastings Nyekanyeka
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:
One other note, the NOT NULL means that the column must have a value
in each row. If NULL was used, that column may be left empty in a given row.
- 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
- Date - A date column in a DBMS-specific format.
- Logical - A column that can hold only two values: TRUE or FALSE.