DBeaver - DBeaver - Universal Database Manager and SQL Client.
Open DBDiff - A database comparison tool for Microsoft SQL Server 2005+ that reports schema differences and...
Neor Profile SQL - MySQL free GUI tool for profiling SQL queries.
MssqlMerge - MssqlMerge is an easy to use diff & merge tool for Microsoft SQL Server databases.
SQL Developer - Oracle SQL Developer is a free, development environment that simplifies the management of Oracle Database in both traditional and Cloud deployments.
DBComparer - Free Compare database tool - DBComparer 3.0 is a professional compare database tool for comparing Microsoft SQL Server 2008 (and 2005) database structure.