Sams Teach Yourself SQL in 21 Days, Fourth Edition

Viewing Table Structure with the DESCRIBE Command

The handy DESCRIBE command enables you to view the structure of a table quickly without having to create a query against the data dictionary.

						DESC[RIBE] table_name
					

Take a look at the two tables you will be using throughout the day:

SQL> describe orders

 Name                            Null?    Type
 ------------------------------- -------- ----
 ORDER_NUM                       NOT NULL NUMBER(2)
 CUSTOMER                        NOT NULL VARCHAR2(30)
 PRODUCT_ID                      NOT NULL CHAR(3)
 PRODUCT_QTY                     NOT NULL NUMBER(5)
 DELIVERY_DATE                            DATE

The following statement uses the abbreviation DESC instead of DESCRIBE:

SQL> desc products Name Null? Type ------------------------------- -------- ...