c# - Replace whitespace outside quotes using regular expression

Question

Using C#, I need to prepare a search text for searching in a SQL Server database using the LIKE command by replacing all whitespace outside quotes with a % character. Example:

Input:

my "search text"

Output:

%my%search text%

Any help would be appreciated. I can handle input strings with an odd number of quotes before replacing the text.

Answer 1

Instead of using a RegEx, use a simple state machine - loop over each character, noting whether you are "in" or "out" of quotes and only replace spaces when you are in the "out" state.