Interactive SQL for PostgreSQL is a database administration solution for managing PostgreSQL databases.

MyISQL (Interactive SQL for MySQL) is a database administration solution for managing MySQL(tm) databases.

Freeware with full source code! The Open QBuilder (OQBuilder) is a simple "visual query builder". You can use OQBuilder in your Delphi and C++Builder applications to make easier SQL-code generation. Supports BDE, ADO, IBO, IBX, DBX, FIBPlus, etc.

Query Builder is a component suite intended for visual building SQL statements for the SELECT, INSERT, UPDATE and DELETE clauses. It allows you to build new queries visually and/or graphically represent the existing queries in your own applications.