How is regex_replace used in Hive?

In Hive, the regex_replace function is used to replace strings that match a regular expression pattern. Its syntax is as follows:

regex_replace(string input, string pattern, string replacement)

In this case, input is the string to be replaced, pattern is the regular expression pattern to be matched, and replacement is the string used to replace the matched part.

For example, if we have a string “Hello, World!” and we want to replace the comma with an exclamation mark, we can use the regex_replace function.

SELECT regex_replace("Hello, World!", ",", "!")

After performing the query above, the result will be “Hello! World!”. The regular expression pattern used here is a simple comma, used to match commas in the string and replace them with exclamation points.