如何处理多种模式的Regex？

Question

I have a requirement where I need to read a query from access db and modify the query to replace all the keywords in the query to SQL executable query.. For eg: say there is a query 'Select key from table1"

here "key" is a reserved keyword.which has to be modified as "Select [key] from table1" (which will work in sql).

there is a possibility that the query can have multiple keywords..so I have a regex as below.

string pattern = "Key|IN|ON|VIEW]";
Regex rgx = new Regex(pattern);

I have the below code..which checks for the patterns..

string pattern = "Key|IN|ON|VIEW]";
Regex rgx = new Regex(pattern);  
string strModifiedQuery = string.Empty;
strModifiedQuery = strQueryText;
foreach (Match m in rgx.Matches(pattern))
{
    Console.WriteLine(m.Value);
    if (m.Value == "Key")
    {
        strModifiedQuery = rgx.Replace(strModifiedQuery, "[Key]");
    }

    if (m.Value == "IN")
    {
        strModifiedQuery = rgx.Replace(strModifiedQuery, "[IN]");
    }

    if (m.Value == "ON")
    {
        strModifiedQuery = rgx.Replace(strModifiedQuery, "[IN]");
    }

Is there a better way in c# to replace the matched pattern with a proper value?

Answer 1

var pattern = @"(?i)Key|IN|ON|VIEW";
var subject = "Select key from table1";
var result = Regex.Replace(subject, pattern, @"[$0]");

Produces

Select [key] from table1

(?i) turns on ignore case and replace pattern [$0] replaces whatever matched surrounded by brackets.