ORACLE- Useful SQL REGEX operators and Metacharacters

Anchoring Metacharacters

Metacharacter	Description
^	Anchor the expression to the start of a line
$	Anchor the expression to the end of a line

Quantifiers, or Repetition Operators

Quantifier	Description
*	Match 0 or more times
?	Match 0 or 1 time
+	Match 1 or more times
{m}	Match exactly m times
{m,}	Match at least m times
{m, n}	Match at least m times but no more than n times

Predefined POSIX Character Classes

Character Class	Description
[:alpha:]	Alphabetic characters
[:lower:]	Lowercase alphabetic characters
[:upper:]	Uppercase alphabetic characters
[:digit:]	Numeric digits
[:alnum:]	Alphanumeric characters
[:space:]	Space characters (nonprinting), such as carriage return, newline, vertical tab, and form feed
[:punct:]	Punctuation characters
[:cntrl:]	Control characters (nonprinting)
[:print:]	Printable characters

Alternate Matching and Grouping of Expressions

Metacharacter		Description
|	Alternation	Separates alternates, often used with grouping operator ()
( )	Group	Groups subexpression into a unit for alternations, for quantifiers, or for backreferencing
[char]	Character list	Indicates a character list; most metacharacters inside a character list are understood as literals, with the exception of character classes, and the ^ and - metacharacters