Regular expression find and replace in Postgres

Question

I have a table that contains a number of rows with columns containing a URL. The URL is of the form:

http://one.example1.com:9999/dotFile.com

I

Answer 1

if you know the url, you don't have to use regex. replace() function should work for you:

replace(string text, from text, to text)        
Replace all occurrences in string of substring from with substring to   
example: replace('abcdefabcdef', 'cd', 'XX')    abXXefabXXef

you could try:

replace(yourcolumn, 'one.example1.com:9999','example2.com')

Answer 2

To replace a fixed string, use the simple replace() function.

To replace a dynamic string, you can use regexp_replace() like this:

UPDATE
  YourTable
SET
  TheColumn = regexp_replace(
    TheColumn, 'http://[^:\s]+:9999(\S+)', 'http://example2.com\1', 'g'
  )