When comparing SchemaSpy vs DbSchema, the Slant community recommends DbSchema for most people. In the question“What are the best database design programs?” DbSchema is ranked 4th while SchemaSpy is ranked 7th. The most important reason people chose DbSchema is:
Includes the possibility to edit tables and data directly in the diagram without writing SQL statements.
Specs
Ranked in these QuestionsQuestion Ranking
Pros

Pro Entity Relationship Digramming for nearly any JDBC-compliant database
SchemaSpy can analyze database metadata in order to reverse engineer ER (Entity Relationship) diagrams for any JDBC-compliant database which includes Oracle, MySQL, Sql-Server and Postgres among others.

Pro Has a GUI option available
SchemaSpy is a CLI tool. For people who prefer GUI-based tools there's one available from a different maintainer which stands on top of the CLI version.
Pro Graphical Diagram Editor
Includes the possibility to edit tables and data directly in the diagram without writing SQL statements.
Pro Multi-platform
Runs on Windows, Mac, and Linux.
Pro Virtual Foreign Keys
If the Database schema is missing real foreign keys, it is possible to create virtual ones to be used within the tool.
Pro Generator for Random Data
Includes the possibility to generate random numerical data or fetch random entries from a text file to populate the database.
Pro Generate schema from existing database
Includes the possibility to generate an ER diagram from an existing database.
Pro SQL editor with syntax highlighting
Includes an SQL editor with syntax highlighting and code completion feature.
Pro Graphical Query Editor
Includes a visual query editor capable of using different join types, filters as well as the 'group by' clause.
Cons

Con Does not work with schema dumpfiles
SchemaSpy has no methods for dealing with when you only have a schema generated via something like (mysqldump --no-data [options] >schema-only_dump.sql
) , and do not currently have access to a live database to connect with.

Con GUI option is a separate download by a different maintainer
Since the GUI version is from a different maintainer, it may be abandoned and eventually break if SchemaSpy development continues beyond that. Or it may implement new features much later than the CLI version.

Con Project may be dead or dying
The codebase on sourceforge hasn't seen an update since 2010.
