I recently encountered the following error in Sonar 3.5

[ERROR] Failed to execute goal org.codehaus.mojo:sonar-maven-plugin:2.0:sonar
(default-cli) on project smartfx: Can not execute Sonar: Missing column:period in DB.ALERTS -> [Help 1]  
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal
org.codehaus.mojo:sonar-maven-plugin:2.0:sonar (default-cli) on project myproject: 
Can not execute Sonar  
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:  203)  
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:  148)  
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:  140)  
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)  

A quick check of the database revealed that the ALERTS table does indeed contain a column named ‘period’.

Solution: Maven was pointing to the wrong database (sonar.jdbc.url in conf/settings.xml).