Java-SQL identifiers are a subset of Java identifiers that can be referenced in SQL.
java_sql_identifier ::= alphabetic character | underscore (_) symbol [alphabetic character | arabic numeral | underscore(_) symbol | dollar ($) symbol ]
Java-SQL identifiers can be a maximum of 255 bytes in length if they are surrounded by quotation marks. Otherwise, they must be 30 bytes or fewer.
The first character of the identifier must be either an alphabetic character (uppercase or lowercase) or the underscore (_) symbol. Subsequent characters can include alphabetic characters (uppercase or lowercase), numbers, the dollar ($) symbol, or the underscore (_) symbol.
Java-SQL identifiers are always case sensitive.
Delimited identifiers are object names enclosed in double quotes. Using delimited identifiers for Java-SQL identifiers allows you to avoid certain restrictions on the names of Java-SQL identifiers.
You can use double quotes with Java-SQL identifiers whether the set quoted_identifier option is on or off.
Delimited identifiers allow you to use SQL reserved words for packages, classes, methods, and so on. Each time you use the delimited identifier in a statement, you must enclose it in double quotes. For example:
create table t1 (c1 char(12) c2 p1.”select”.p2.”jar”)
Double quotes surround only individual Java-SQL identifiers, not the fully qualified name.
For additional information about identifiers, see Chapter 5, “Transact-SQL Topics,” in the Reference Manual.