substring

The substring() function returns part of a string value, determined by character positions within the string. Character positions are counted from one.

For example, the expression «substring('Goldfarb', 5, 3) » returns the string «far » .

Argument	Data Type	Meaning
input	xs:string?	The containing string
start	xs:double	The position in the containing string of the first character to be included in the result string
length (optional)	xs:double	The number of characters to be included in the result string If the argument is omitted, characters are taken from the start position up to the end of the containing string.
Result	xs:string	The required substring of the containing string