sql server - vsdbcmd.exe generate drop constraint instructions without constraint name -

when generating diff script between 2 dbschema vsdbcmd.exe, sometime obtain unexpected output, containing drop constraint without name of constraint :

go print n'dropping on column: columnname ...';      go alter table tablename drop constraint ; 

in our schema, column has default value constraint, auto generated name. expected vsdbcmd.exe generate valid alter table sql statement, specified in msdn library :

alter table [ database_name . [ schema_name ] . | schema_name . ] table_name drop { [ constraint ] constraint_name | column column_name }

do have idea of prevent vsdbcmd.exe generate valid sql statement ?

this issue occurs when constraint has generated name. explicitly named constraint not impacted. therefore, solution name every constraint.