Derby implements an
SQL-92 core subset, as well as some SQL-99 features.
This section provides an overview of the current SQL language by describing
the statements, built-in functions, data types, expressions, and special characters
it contains.
SQL expressions
Syntax for many statements and expressions includes the term Expression, or a term for a specific kind of expression such as TableSubquery. Expressions are allowed in these specified places within statements.
SYSCS_DIAG diagnostic tables and functions
Derby provides a set of system table expressions which you can use to obtain diagnostic information about the state of the database and about the database sessions.