This morning I was asked to do a quick and dirty query to find all rows from a table in MS SQL Server where a particular column contained one or more pecent sign (%) charaters.  Considering the '%' character is a wildcard, I obviously needed an escape sequence, but oddly I had never run across this particular problem before.  After a quick search I found what appears to be a Microsoft-specific solution that suited my needs.  You can use an escape character in your 'where' clause, then define that character at the end of your query by adding {escape '[your character]'} like this:

SELECT
    MyColumn
FROM
    MyTable
WHERE
    MyColumn like '%\%%'
{escape '\'} 

I would like to underscore that the backslash character in my statement can be whatever you need it to be in case that is another point of conflict for you.