Remove a random expression from string

Question

I have a string/column something like this

String a = \"000003023_AggregateStopLossLimit_W x3A 973911_2012-12-22.PDF\";

I want to create a subs

Answer 1

The Java solution given by @Kent above is very elegant and I recommend it. That said, if you want to accomplish this using Oracle's regex engine, you might try the following:

WITH t1 AS (
    SELECT '000003023_AggregateStopLossLimit_W x3A 973911_2012-12-22.PDF' AS filename
      FROM dual
)
SELECT filename, REGEXP_REPLACE(filename, ' [^_]*', '')
  FROM t1