Are
you looking for very simple and lightweight tool that generates ER diagram from
commonly used DBs. SchemaSpy tool
will help you to understand all the relationships in DB schema. This week blog
is about SchemaSpy tool.
About SchemaSpy:
SchemaSpy
is a Java-based tool (requires Java 5 or higher) that analyzes the metadata of a schema in
a database and generates a visual representation of it in a browser-displayable
format. It lets you click through the hierarchy of database tables via child
and parent table relationships as represented by both HTML links and
entity-relationship diagrams. It's also designed to help resolve the obtuse
errors that a database sometimes gives related to failures due to constraints.
It’s free.
SchemaSpy uses
JDBC's database metadata extraction services to gather the majority of its
information, but has to make vendor-specific SQL queries to gather some
information such as the SQL associated with a view and the details of check
constraints. The differences between vendors have been isolated to
configuration files and are extremely limited. Almost all of the
vendor-specific SQL is optional.
Browse
some sample
pages generated by SchemaSpy. Note that this was run against an extremely
limited schema so it doesn't show the full power of the tool.
SchemaSpy
is a command line tool. If you are interested to work with GUI based tools. Try
Its GUI tools using http://www.joachim-uhl.de/projekte/schemaspygui/
Running SchemaSpy
You run SchemaSpy from the command
line:|
|
java -jar schemaSpy.jar -t dbType -db dbName [-s
schema] -u user [-p password] -o outputDir |
More
details to explore SchemaSpy can be found below:
Happy Learning,
Nanjundan Chinnasamy
