data Difference between two schemas in Liquibase

Hi All,

I am running the below command
java -jar liquibase.jar
 --driver=<driver name>
 --clasapth=<classpath + liquibase jar>
 --changeLogFile=<file name + path>
 --url=<schema1>
 --username=<username>
 --password=<pwd>
 --referenceUrl=<schema2>
 --referenceUsername=<username>
 --referencePassword=<pwd>
 --diffTypes=data
generateChangeLog


This command gives me a file dump with xKB , the file contains only the changeSet of the (url+username+password) DB, not the actual comaprison between both the tables and values of each table.

can you please help me with the correct command if the above one is wrong ?