Multiple Patterns in Regex

Question

Can there be multiple patterns in Regexp_Replace.

Pattern 1 : '^#.*'

Pattern 2: '^//.*'

Pattern 3 : '^&&.*'

I want all three patterns in same regexp_replace function like

select REGEXP_REPLACE ('Unit testing last level','Pattern 1,Pattern 2,Pattern 3','',1,0,'m') 
  from dual;

Answer 1

You can use an alternation group where all alternative branches are | -separated.

^(#|//|&&).*

The (...) form a grouping construct where you may place your various # , && , and other possible "branches". A | is an alternation operator.

The pattern will match:

• ^ - start of a line (as you are passing m match_parameter)
• (#|//|&&) - either # , // or &&
• .* - any 0+ chars other than a newline (since n match_parameter is not used).