Running SchemaSpy for database tables in SQL Server 2005

I was looking for a tool to generate the schema diagram from my SQL Server 2005 development database.  After some research I found the open source tool SchemaSpy which meet my needs, it also had decent reviews in few blogs.  But I had problem running the tool to generate the Html documents for my schema.

After playing around with the option parameters, I was finally able to get it to generate the documentation needed.  Couple of things to ensure before running schemaspy to generate documentation for SQL Server 2005 schema.

• Download Microsoft JDBC driver for SQL Server 2005 
• Download Graphviz

Make sure the Graphviz installation is added to your system PATH variable.  Run the following command

java -jar schemaSpy.jar -t mssql05 -db <name of the database> -host <Ip address/hostname> -s dbo -port 1433 -u <username of the database> -p <Password for the userId> -o library

Difference between Static and Singleton Pattern

I wanted to blog about this for a while, b'cos I found many folks not being able to answer this question during the interview process.  Few differences worth mentioning are

• Singletons can implement interfaces and inherit from other classes (while static classes cannot).
• Singletons can be extended (used as a subclass) while static classes cannot.
• There is only one instance in case of Singletons but there is none in case of Static classes.
• Singletons can be passed around as a parameter to function calls but you can't do that with a Static class.