![]() The g flag is the greedy flag that returns, replaces all occurrences of the pattern. We use the PostgreSQL g flag in our use more often than not. The ones we commonly use are, regexpreplace, and regexpmatches. Flag g causes the function to find each match in the string, not only the first one, and return a row for each such match. Regular Expressions in PostgreSQL PostgreSQL has a rich set of functions and operators for working with regular expressions. The flags parameter is an optional text string containing zero or more single-letter flags that change the function's behavior. Regular expressions (REs), as defined in POSIX 1003.2, come in two forms: extended REs or EREs (roughly those of egrep), and basic REs or BREs (roughly. Much of the description of regular expressions below is copied verbatim from his manual. If the pattern contains parenthesized subexpressions, the function returns a text array whose n'th element is the substring matching the n'th parenthesized subexpression of the pattern (not counting "non-capturing" parentheses see below for details). PostgreSQL 's regular expressions are implemented using a software package written by Henry Spencer. If the pattern contains no parenthesized subexpressions, then each row returned is a single-element text array containing the substring matching the whole pattern. If the pattern does not match, the function returns no rows. The function can return no rows, one row, or multiple rows (see the g flag below). The delimiter is defined with a regular expression similar to the previous example. ![]() It has the syntax regexp_matches(string, pattern ). The regexp_matches function returns a text array of all of the captured substrings resulting from matching a POSIX regular expression pattern. SELECT regexp_matches(column,'^stuff.*$')
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