XQuery

Literals

Literals are simply constant values that are directly represented in a query, such as "ACC" and 29.99. They can be used in expressions anywhere a constant value is needed, for example the strings in the comparison expression:

if ($department = "ACC") then "accessories" else "other"

or the numbers 1 and 30 in the function call:

substring($name, 1, 30)

There are two kinds of literals: string literals, which must be enclosed in single or double quotes, and numeric literals, which must not. Numeric literals can take the form of simple integers, such as 1, decimal numbers, such as 1.5, or floating-point numbers, such as 1.5E2. The processor makes assumptions about the type of a numeric literal based on its format.

You can also use type constructors to convert your literal values to the desired type. For example, to include a literal date in an expression, you can use xs:date("2006-05-03"). For literal Boolean values, you can use the expressions true( ) and false( ).