Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
gmi

Test String

Code Generator

Language

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "(SELECT|DELETE)(?:\\s*\\/\\*.*\\*\\/\\s*?)*\\s+FROM*\\s+([^\\s\\/*;]+)?|(?:(?:(CREATE|ALTER|DROP)(?:(?:\\s*\\/\\*.*\\*\\/\\s*?)*\\s+OR(?:\\s*\\/\\*.*\\*\\/\\s*?)*\\s+(REPLACE))?)(?:\\s*\\/\\*.*\\*\\/\\s*?)*\\s+TABLE(?:(?:\\s*\\/\\*.*\\*\\/\\s*?)*\\s+IF(?:\\s*\\/\\*.*\\*\\/\\s*?)*\\s+EXISTS)?|(UPDATE)|(ALTER)|(INSERT)(?:\\s*\\/\\*.*\\*\\/\\s*?)*\\s+(?:INTO?))(?:\\s*\\/\\*.*\\*\\/\\s*?)*\\s+([^\\s\\/*;]+)|(?:(REPLACE)(?:\\s*\\/\\*.*\\*\\/\\s*?)*\\s+(?:INTO?))(?:\\s*\\/\\*.*\\*\\/\\s*?)*\\s+([^\\s\\/*;]+)(?:\\s*\\/\\*.*\\*\\/\\s*?)*\\s+([^\\s\\/*;]+)"; final String string = "DROP TABLE IF EXISTS tbl1; CREATE TABLE tbl1 ...\n" + "CREATE TABLE tbl1 ...\n" + "CREATE OR REPLACE TABLE tbl1 ...\n" + "INSERT /*some comment*/ INTO tbl2 ...\n" + "INSERT /*some comment*/ INTO tbl2 ...\n" + "UPDATE tbl3 SET col1 = ...\n" + "/*some garbage comments*/ UPDATE tbl3 SET col1 = ... \n" + "DELETE from tbl4 ...\n" + "select from select_table insert into table_ttt\n" + "alter table alter_table \n" + "#1 some optional statements like CREATE /*some comments*/ TABLE table_name everything else\n" + "#1 some optional statements like CREATE /*some comments*/ OR REPLACE TABLE table_name everything else\n" + "#2 some optional statements like INSERT /*some comments*/ INTO /*some comments*/ table_name\n" + "#3 some optional statements like UPDATE /*some comments*/ table_name everything else"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE | Pattern.CASE_INSENSITIVE); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html