HTSQL a high-level query language and Web service gateway for relational databases. It comes with source code and is royalty free for any use with open source database systems such as MySQL, PostgreSQL, SQLite, etc. Licenses for using HTSQL in conjunction with proprietary databases such as Microsoft SQL and Oracle can be purchased.
Cinisis is a PHP library for reading CDS/ISIS databases. It's intended for integrating or migrating existing ISIS databases into other applications. It is a wrapper around other ISIS libraries and tools, providing a uniform interface and iterators for easily fetching data without bothering with internals.
FreeTable is a cloud database service that allows programmers to upload and download individual data values using a SQL-like API. Language bindings exist for Python, PHP, and Ruby. In many respects FreeTable is a data wiki, with notions of revision history, curation, and data rollback/roll forward.
STK/Unit is a pure SQL testing framework for MariaDB and MySQL. Users can create Base Tests (Stored Procedures) which are part of Test Cases (databases) and, optionally, Test Suites (other Stored Procedures). Output is stored in internal tables. You can convert it to a human-readable string, valid HTML, or query some convenient views which group results. It can be used to test any SQL structure (tables, views, triggers, stored routines), as well as server upgrades or configuration changes.