Regexp_Instr : REGEXP_INSTR « Regular Expressions Functions « Oracle PL/SQL Tutorial

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Oracle PL/SQL Tutorial » Regular Expressions Functions » REGEXP_INSTR 




REGEXP_INSTR function returns a number for the position of matched pattern.

Unlike INSTR, REGEXP_INSTR cannot work from the end of the string backward.

The arguments for REGEXP_INSTR are:

REGEXP_INSTR(String to search, Pattern, [Position,[Occurrence, [Return-option, [Parameters]]]])
  1. Pattern is the sought string, which will be expressed as an RE.
  2. These first two arguments are not optional.
  3. Position is the place in 'String to search' to begin the search for Pattern. The default is 1.
SQL> SELECT REGEXP_INSTR('This is a test','a') position FROM dual;

  POSITION
----------
         9

SQL>














18.2.REGEXP_INSTR
18.2.1.Regexp_Instr returns the location (beginning) of a pattern in a given string
18.2.2.REGEXP_INSTR(x, pattern [, start [, occurrence [, return_option [, match_option]]]]) searches for pattern in x.
18.2.3.Regexp_Instr
18.2.4.Parameters is a field that may be used to define how one wants the search to proceed:
18.2.5.Find the 's' and ignore case.
18.2.6.The simplest regular expression matches letters, letter for letter
18.2.7.SELECT REGEXP_INSTR('Two is bigger than One','One') where_it_is
18.2.8.Occurrence refers to the first, second, third, etc., occurrence of the pattern in S. The default is 1 (first).
18.2.9.Return-option returns the position of the start or end of the matched string.
18.2.10.The Return-option is set to 1 to indicate the end of the found pattern
18.2.11.Returns the position of the second occurrence that matches the regular expression s[[:alpha:]]{3} starting at position 1:
18.2.12.Returns the position of the second occurrence that matches the letter o starting at position 10 using REGEXP_INSTR()
18.2.13.Specify any series of letters and find matches, just like INSTR
18.2.14.regexp_instr(comments, '[^ ]+', 1, 9) > 0
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