using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"(?:\bfrom\b(?:\s*#\w+(?:\s*\w+))*+|(?!^)\G),?\s*\K(?!(?:\w+ )?\bwhere\b)([\w ]+)(?=[^w]*(?:\bw(?!here\b)[^w]*)*\bwhere\b)";
string input = @"select ... from course
where ...
select ... from course c, marks s
where ....
select ... from #prefix#course c, marks m
where ...
select ... from #prefix#course c
where id = (select ... from student s where ...)";
foreach (Match m in Regex.Matches(input, pattern))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx