Data Types

Almost all commercial databases (and programming languages) offer a standard set of data types. These cover a multitude of situations, but not all.

It is usually possible to declare a field (or column) required, and to define a default value for it.

Name Description
Binary A number in the base 2 format
BLOB Binary Large Object (often an image)
Boolean A True or false value
Character Any combination of letters, symbols, and numeric characters. For example, valid character data includes “928”, “Johnson”, and “(0*&(%B99nhjkJ”
Date A calendar date like June 16, 1950. Format is defined in the application.
Decimal A signed decimal number with up to 38 digits. The number of decimal places is specified, and can be up to 38.
Integer A signed number with no decimal point (32-bit signed integers, can go from -2,147,483,648 to +2,147,483,647). (64 bit signed integers can be much bigger)
Long Variable Character A potentially long string of unspecified length, typically used for “Comments” or “Notes”. It does not take up more space or require a length definition as a long string would.
String Text of a specified length.
Time 24 hour time. Format is defined in the application.
Posted in Database Types & Terms


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