lib4d_sql is a C library that provides the required functions (connect, prepare, execute, etc.) for writing an SQL client for 4D databases. It uses the public 4D SQL protocol, which is supported by 4D products since version 11. It is already used by the PDO_4D Open Source project, and it might be used to provide others drivers for JDBC, ADO, or ActiveRecord.
StelsCSV is a JDBC driver that allows performing SQL statements and other JDBC operations upon text files (comma separated, tab-separated, fixed length, etc.). Using this driver, users can easily create a simple database consisting of plain text files. The driver can be used for writing data importing programs and migration tools. It supports most keywords of ANSI SQL92, table joins, INSERT, UPDATE, and DELETE statements, data types, aggregate, converting, string, and user-defined SQL functions.