![]() ![]() It can be a combination of the following: Value The regular expression matching information. It can be CHAR, VARCHAR2, NCHAR, NVARCHAR2, CLOB, or NCLOB. Examplesįind groups of "word characters" (letters, numbers and underscore) ending with "thy" in the string "healthy, wealthy, and wise" and replace them with nothing.The syntax for the REGEXP_REPLACE function in Oracle is: REGEXP_REPLACE( string, pattern ] ] ] ) Parameters or Arguments string The string to search. You can also name captured subexpressions to make your regular expressions less ambiguous. For example, \g0 is the substring captured by the first set of parentheses followed by a zero. To force this Oracle behavior in Vertica, use the \g back reference and enclose the number of the captured subexpression in curly braces. In Oracle, \10 is treated as the substring captured by the first set of parentheses, followed by a zero. In Vertica, you can use \10 in the replacement pattern to access the substring captured by the tenth set of parentheses in the regular expression. All spaces in the regular expression that you want to be matched in strings must be escaped with a backslash ( \) character.Īnother key difference between Oracle and Vertica is that Vertica can handle an unlimited number of captured subexpressions, while Oracle is limited to nine. Comments start with a hash ( #) character and end with a newline ( \n). Using the x modifier causes the function to ignore all unescaped space characters and comments in the regular expression. operator matches any character except a newline.Īdd comments to your regular expressions. Without the m modifier, the start and end of line operators match only the start and end of the string.Īllow the single character regular expression operator (. Using this modifier, the start of line ( ^) and end of line ( $) regular expression operators match line breaks ( \n) within the string. Treat the string to match as multiple lines. Treat strings as binary octets, rather than UTF-8 characters.įorce the match to be case sensitive (the default). One or more single-character flags that modify how the regular expression finds matches in string: For example, setting this parameter to 3 returns the position of the third substring that matches the pattern. Use this parameter to find the position of subsequent matching substrings. By default, the function returns the position of the first matching substring. Setting this parameter to a value greater than 1 begins searching for a match at the nth character you specify.Ĭontrols which occurrence of a pattern match in the string to return. By default, the function begins searching for a match at the first (leftmost) character. The number of characters from the start of the string where the function should start searching for matches. The first captured substring is inserted into the replacement string using \1, the second \2, and so on. The replacement string can contain backreferences for substrings captured by the regular expression. If you do not supply a replacement, the function deletes matched substrings. The string to replace matched substrings. See the Perl Regular Expressions Documentation for details. The syntax of the regular expression is compatible with the Perl 5 regular expression syntax. The regular expression to search for within the string. If string exists in a _raw_ column of a flex or columnar table, cast string to a LONG VARCHAR before searching for pattern. The VARCHAR or LONG VARCHAR string to search for a regular expression pattern match. Syntax REGEXP_REPLACE( string, target ]]] ) ![]() If you are porting a regular expression query from an Oracle database, remember that Oracle considers a zero-length string to be equivalent to NULL, while Vertica does not. This function operates on UTF-8 strings using the default locale, even if the locale has been set to something else. It is similar to the REPLACE function, except it uses a regular expression to select the substring to be replaced. Replace all occurrences of a substring that match a regular expression with another substring. ![]()
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