Regular expressions

Regular expressions are a sequence of characters used to identify patterns in identifiers and string values. InfluxQL supports regular expressions in the following operations:

Query performance

Regular expression comparisons are more computationally intensive than exact string comparisons. Queries with regular expressions are not as performant as those without.

Regular expression syntax

InfluxQL Regular expressions are surrounded by / characters and use the Go regular expression syntax.


Regular expression flags

Regular expression flags modify the pattern-matching behavior of the expression. InfluxQL supports the following regular expression flags:

mmulti-line mode: ^ and $ match begin/end line in addition to begin/end text
slet . match \n
Uungreedy: swap meaning of x* and x*?, x+ and x+?, etc.

Include regular expression flags at the beginning of your regular expression pattern enclosed in parentheses (()) and preceded by a question mark (?).


Regular expression operators

InfluxQL provides the following regular expression operators that test if a string operand matches a regular expression:

  • =~: Returns true if the string matches the regular expression
  • !~: Returns true if the string does not match the regular expression

InfluxQL regular expression operators are used to test string column values in the WHERE clause.

Regular expression examples

The examples below use the following sample data sets:

Use a regular expression to specify field keys and tag keys in the SELECT clause

Use a regular expression to specify measurements in the FROM clause

Use a regular expression to specify tag values in the WHERE clause

Use a regular expression to specify a tag with no value in the WHERE clause

Use a regular expression to specify tag keys in the GROUP BY clause

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