The topic "JDBC escape syntax for fn keyword" (http://db.apache.org/derby/docs/dev/ref/rrefjdbc88908.html) does not include all the functions listed in Appendix C of the JDBC specification that Derby supports.
The following numeric functions, listed in Section C.1, are implemented in Derby but not listed in this topic:
Three numeric functions listed in Section C.1 are not yet implemented in Derby; they should be added to this topic when they are. (See DERBY-3893.)
A number of the string functions listed in Section C.2 are not implemented in Derby. Of the ones that are, the following are not listed in the JDBC escape syntax topic:
Some of the time and date functions listed in Section C.3 are not implemented in Derby. Of the ones that are, only two (TIMESTAMPADD and TIMESTAMPDIFF) are listed in the JDBC escape syntax topic. The following should be added:
Two of the three system functions listed in Section C.4 are not implemented in Derby. The one that is, USER(), is not listed in the JDBC escape syntax topic.
The functions should be listed in groups by type of function, and the fonts should conform with Derby documentation style.