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Categories / MySQL Tutorial / Regular Expressions

 

{n} or {m,n} notation provides a more general way of writing regular expressions

{n} or {m,n} notation matches many occurrences of the previous atom (or "piece") of the pattern. m and n are integers. a*: Can be written as a{0,}. a+: Can be written as a{1,}. a?: Can be written as a{0,1}. a{n} matches exactly n instances of a. a{n,} matches n or more instances of a. a{m,n} matches m through n instances of a, inclusive. m and n must be in the range from 0 to RE_DUP_MAX (default 255), inclusive. If both m and n are given, m must be less than or equal to n. mysql> mysql> SELECT 'abcde' REGEXP 'a[bcd]{2}e'; +-----------------------------+ | 'abcde' REGEXP 'a[bcd]{2}e' | +-----------------------------+ |                           0 | +-----------------------------+ 1 row in set (0.01 sec)