Thus, the preceding regular expression matches these strings: The question mark ( ?) indicates that the preceding element, s, is optional. The pipe symbol ( |) indicates a choice between the elements on either side of it, f and ht. Parentheses group multiple pattern elements into a single element. The character literals are f, ht, tp, s, and the colon ( :). The metacharacters (which are also operators) in the preceding example are the parentheses, the pipe symbol ( |), and the question mark ( ?). For example, this regular expression matches any string that begins with either f or ht, followed by tp, optionally followed by s, followed by the colon ( :): A regular expression specifies a search pattern, using metacharacters (which are, or belong to, operators) and character literals (described in Oracle Database SQL Language Reference).
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |