A Table: The Primary Storage for Data
The table is the primary storage object for data in a relational database. A table consists of row(s) and column(s), both of which hold the data. A table takes up physical space in a database and can be permanent or temporary.
Fields and Columns
A field, also called a column in a relational database, is part of a table that is assigned a specific data type; a field should be named to correspond with the type of data that will be entered into that column. Columns can be specified as NULL or NOT NULL, meaning that if a column is NOT NULL, something must be entered. If a column is specified as NULL, nothing has to be entered.
Every database table must consist of at least one column. Columns are those elements ...
Get Sams Teach Yourself SQL in 24 Hours, Second Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
