PagingHelper.SplitSQL does not work when query has comments

[MarcosLopezC]

PagingHelper.SplitSQL(string, out SQLParts) method doesn't handle queries with comments. Here is a test case to illustrate the issue:

[Test]
public void EnsureSplitSQLHandlesComments()
{
    var sql = @"/* comment */ select a, b, c from example order by a;";

    PagingHelper.SQLParts parts;
    PagingHelper.SplitSQL(sql, out parts);

    Assert.AreEqual("order by a", parts.sqlOrderBy);
    Assert.AreEqual("SELECT COUNT(*) FROM (select a, b, c from example ) npoco_tbl", parts.sqlCount);
}

The root of the problem seems to be the Regex PagingHelper.rxColumns. It doesn't take comments into account:

public static Regex rxColumns = new Regex(@"\A\s*SELECT\s+((?:\((?>\((?<depth>)|\)(?<-depth>)|.?)*(?(depth)(?!))\)|.)*?)(?<!,\s+)\bFROM\b", RegexOptions.IgnoreCase | RegexOptions.Multiline | RegexOptions.Singleline | RegexOptions.Compiled);

One possible solution could be to strip comments before the call to .Match():

var m = rxColumns.Match(sql);