This is very very basic, "NO space in an identifier", be it a variable name, object name, function name, class name, table name, or field name. You may get away with it by enclosing such an identifier with back tick in MySQL or [] in SQL Server, but what the heck. Just don't include a space.
If a name consists of multiple words, use underscore to separate them or
Camel case - Wikipedia[
^].