Run here with VSDBCMD.EXE. Then see Compare DTE Commands .
I suspect something like
devenv /Command Data.NewSchemaComparison [/ProviderType ConnectionBased | ProjectBased | FileBased] [/ConnectionString connection] | [/DatabaseName databaseName] | [/ConnectionName name] | [ProjectName proj] | [/FileName fileName] [/DspFamily family][ProviderType ConnectionBased | ProjectBased | FileBased] [/ConnectionString connection] | [/DatabaseName databaseName] | [/ConnectionName name] | [ProjectName proj] | [/FileName fileName] [/DspFamily family]
I hope there is a similar command to compare the data.
source share