The origin text is:
sqoop export --columns int_id,date_time,mr_count,ecno_pollution,rscp_0,rscp_1,rscp_2,rscp_3,rscp_4,rscp_5,load_time --input-field
The target text is:
sqoop export --columns int_id,date_time,mr_count,ecno_pollution,rscp0,rscp1,rscp2,rscp3,rscp4,rscp5,load_time --input-field
We want remove all underscore in "rscp_3", which means converting it to "rscp3". The real text has ninety more items, so we can't do substitutions manually. And other items also use underscore, so you can't only remove all underscores.
Solution: :s/rscp_\(\d\+\)/rscp\1/gc.
We use "(" and ")" to mark a group, use "\1" to represent it in the new strings.