Question

In oracle documentation the below statement is there.

metachatecters are <([{\^-=$!|]})?*+.>

There are two ways to force a metacharacter to be treated as an ordinary character:

    * precede the metacharacter with a backslash, or
    * enclose it within \Q (which starts the quote) and \E (which ends it).

first way i understood.

Can any one explain about second way in details ?

Thanks

Answer 1

* enclose it within \Q (which starts the quote) and \E (which ends it).

consider metacharacter $ and now you want this to be treated as a normal character, using 2nd way you have to enclose $ between \Q and \E like below:

 "\\Q$\\E" (eqvivalent to `\\$`)

Note that however, you still have to escape \Q and \E with extra backslashes as they are not valid escape sequences.