Regex Extract a string between two words containing a particular string - regex

Question

I have the below string
abc-12d-ef-oy-5678-xyz--**--20190120075439322am--**--ghi-66d-ef-oy-8877-sdf--**--sfdfdsgfg--**--20190120075765487am
It is kind of multi character delimited string, delimited by '--**--' I am trying to extract the first and second words which has the -oy- tag in it. This is a column in a table. I am using the regex_extract method but i am not able extract the string which contains a string and ends with a string.
Here is one pattern that i tried .*(.*oy.*)--

Answer 1

If the -oy- can not be at the start or at the end, you could use this pattern to match the 2 hyphen delimited strings with -oy-:
[a-z0-9]+(?:-[a-z0-9]+)*-oy(?:-[a-z0-9]+)+
Regex details
[a-z0-9]+ Match 1+ times a-z0-9
(?: Non capturing group
-[a-z0-9]+ Match - and 1+ times a-z0-9
)* Close group and repeat 0+ times
-oy Match literally
(?:-[a-z0-9]+)+ Repeat 1+ times a group which will match - and 1+ times a-z0-9
You can extend the character class [A-Za-z0-9] to allow what you want to match like uppercase chars.
Regex demo | Java demo
If the matches should be between delimiters, you could use a positive lookbehind and positive lookahead and an alternation:
(?<=^|--\\*\\*--)[a-z0-9]+(?:-[a-z0-9]+)*-oy(?:-[a-z0-9]+)+(?=--\\*\\*--|$)
See a Java demo

Answer 2

You can use this regex which will match string containing -oy- and capture them in group1 and group2.
^.*?(\w+(?:-\w+)*-oy-\w+(?:-\w+)*).*?(\w+(?:-\w+)*-oy-\w+(?:-\w+)*)
This regex basically matches two strings delimiter separated containing -oy- using this (\w+(?:-\w+)*-oy-\w+(?:-\w+)*) to capture the text.
Demo

Answer 3

Are you able to select values from capture groups?
(?:--\*\*--|^)(.*?-oy-.*?)(?:--\*\*--|$)
?: - Non-capture group, matches the delimiter, begin of line, or end of line but does not create a capture group
*? - Lazy match so you only grab the contents of the field
https://regex101.com/r/aUAvcx/1
--- Second stab at this follows ---
This is convoluted. Hopefully you can use Lookahead and Lookbehind. The last problem I had was the final record was being "Greedy" and sucking up the field before it too. So I had to add an exclusion in the capture group for your delimiter.
See if this works for you.
(?<=--\*\*--|^)((?:(?:(?!--\*\*--).)*)-oy-(?:(?:(?!--\*\*--).)*))(?=--\*\*--|$)
https://regex101.com/r/aUAvcx/3
Basically the (?: are so we are not getting too many capture groups to work with.
There are three parts to this:
The lookbehind - Make sure the field is framed by the delimiter (or start of line)
The capture group - Grab the contents of the field, making sure a delimiter isn't sucked up into it
The lookahead - Make sure the field is framed by the delimiter (or end of line)
As far as the capture group goes, I check the left and right side of the -oy- to make sure the delimiter isn't there.