Some query tools available for Linux-based databases include:
A database front end for KDE using the
hk_classes C++ class that provides a C++-based
access scheme very similar to ODBC.
Zaval Database Front-end (JDBC + Web)
DataVision is a database reporting tool similar to Crystal Reports. Reports can be viewed and printed from the application or output as HTML, LaTeX2e, XML, DocBook, or tab- or comma-separated text files. From the LaTeX2e and DocBook output files you can in turn produce PDF, text, HTML, PostScript, and more.
A KDE application that wants to be somewhat equivalent to MS Access.
Generate Reports in PDF, HTML, TXT, and CSV, with an XML-based report definition scheme. Licensed under either the GPL or a traditional commercial license.
A commercial server-based report generator for use with MySQL™ and Oracle . Version 3 has added graphing. Bar, pie, line and scatter graphs are supported. It functions with most any browser, with no client code to install. Free 30 day trial available.
Last updated in about 1999...
Pentaho - Open SourceBusiness Intelligence - a "data warehouse" framework for PostgreSQL