Java-SQL class names (identifiers) are limited to 255 bytes. Java-SQL field and method names can be any length, but they must be 255 bytes or less if you use them in Transact-SQL. All Java-SQL names must conform to the rules for Transact-SQL identifiers if you use them in Transact-SQL statements.
Class, field, and method names of 30 or more bytes must be surrounded by quotation marks.
The first character of the name must be either an alphabetic character (uppercase or lowercase) or an underscore (_) symbol. Subsequent characters can include alphabetic characters, numbers, the dollar ($) symbol, or the underscore (_) symbol.
Java-SQL names are always case sensitive, regardless of whether the SQL system is specified as case sensitive or case insensitive.
See Java-SQL identifiers for more information about identifiers.