String data

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A string is composed of zero or more characters: letters, digits, spaces, or special symbols. A string with no characters is called an empty string or a null string (not to be confused with the null data type).

The maximum number of characters allowed in a string depends on where that string is stored. In dBASE Plus, the maximum is approximately 1 billion characters, if you have enough virtual memory. For DBF (dBASE¨) tables, you may store 254 characters in a character field and an unlimited number in a memo field. For DB (Paradox) tables, the limit is 255 characters in an alpha field, and no limit with memo fields. Different database servers on different platforms each have their own limits.

Literal character strings must be enclosed in matching single or double quotation marks, or square brackets, as shown in the following examples:

'text'

"text"

[text]

A literal null string, or empty string, is indicated by two matching quotation marks or a set of square brackets with nothing in between.