Oracle® Web Application Programming for PL/SQL® Developers

Unit 19.6. Searching and Replacing Text

Regular Expressions

Though PL/SQL’s INSTR and SUBSTR functions perform efficient text manipulation, the OWA_PATTERN package provides procedures and functions that perform more complex text manipulation than is possible with their PL/SQL predecessors. Regular expressions make this sophistication possible. A regular expression is a string/pattern of characters used to find matches within another string of characters. Chances are you have used a simple regular expression to perform wildcard file searches using commands such as ls *.txt, dir *.txt, and Oracle’s LIKE statement with the wildcard character, %. Additionally, you learned about JavaScript regular expressions in Chapter 14, “JavaScript Form Validation.” ...