The meta-symbols of BNF are listed in the following table.
BNF meta-symbols
This table lists the BNF meta-symbols used in SQL syntax examples and describes their meanings.
Symbol
Meaning
|
Or. Choose one of the items.
[ ]
Encloses optional items.
*
Flags items that you can repeat 0 or more times. Has a
special meaning in some SQL statements.
{ }
Groups required items so that they can be marked with the
symbol |.
( ) . ,
Other punctuation that is part of the syntax.
The following example shows how SQL syntax is presented:
CREATE [ UNIQUE ] INDEX indexName
ON tableName ( simpleColumnName [ , simpleColumnName ]* )
Command-line syntax for running Java programs and utilities (as
well as examples) always begins with the command java: java org.apache.derby.tools.ij
This documentation attempts to be JVM neutral, but any command line examples or syntax using JVM specific references should be verified with your JVM documentation.