Oracle Database 11g PL/SQL Programming

APPENDIX ERegular Expression Primer

Regular expressions in Oracle 11g enable you to perform powerful context searches in variable-length strings, like the CHAR, CLOB, NCHAR, NCLOB, NVARCHAR2, and VARCHAR2 character datatypes. They are strings that describe or match a set of strings. They provide a powerful set of pattern matching capabilities by combining character classes, collation classes, metacharacters, metasequences, and literals. Character classes are groups of possible characters at a point in the search. Collation classes are sets of characters and are treated like a range. Metacharacters are operators that specify search algorithms, and metasequences are operators created by two metacharacters or literals. Literals are characters, character ...