The WHERE clause consists of 1..n filters
combined with AND and OR operators.
A filter consists of a filter type,
an operator and 0..n filter values.
A filter value in MQL is an
arbitrary sequence of characters bounded by single quotes ('). Integer values,
Long values, Double values, date values, or keywords, such as ME, TODAY, and
YESTERDAY etc. can be used as filter values without the single quotes.
To include a single-quote character within a filter value, write two
adjacent single quotes.