Follow the syntax conventions below when creating or editing expressions:
•Enclose data field names in square brackets (for example, [Products.ProductName]).
•Type a question mark before query parameters names (for example, ?parameter1).
Add the "Parameters" prefix before report parameters names (for example, [Parameters.parameter1]).
•Enclose string values in apostrophes (for example, 'USA'). An attempt to use quotes instead results in an error.
Type a double apostrophe to embed an apostrophe into an expression's text (for example, 'It''s sample text').
•Enclose date-time constants in hashtags (for example, [OrderDate] >= #1/1/2016#).
•Use a question mark to represent a null reference (one that does not refer to any object) (for example, [Region] != ?).
•If an expression uses different types, you can convert them to the same type using dedicated functions (for example, Max(ToDecimal([Quantity]),[UnitPrice])).