Data Types

When defining the fields in a database table, we must give each field a data type. For example, the field Birth Year is a year, so it will be a number, while First Name will be text. Most modern databases allow for several different data types to be stored. Some of the more common data types are listed here:

• Text: for storing non-numeric data that is brief, generally under 256 characters. The database designer can identify the maximum length of the text.

• Number: for storing numbers. There are usually a few different number types that can be selected, depending on how large the largest number will be.

• Yes/No: a special form of the number data type that is (usually) one byte long, with a 0 for “No” or “False” and a 1 for “Yes” or “True”.

• Date/Time: a special form of the number data type that can be interpreted as a number or a time. • Currency: a special form of the number data type that formats all values with a currency indicator and two decimal places.

• Paragraph Text: this data type allows for text longer than 256 characters. • Object: this data type allows for the storage of data that cannot be entered via keyboard, such as an image or a music file.