import arcpy, os
from arcpy import env
arcpy.env.overwriteOutput = True
env.workspace = arcpy.GetParameterAsText(0)
output = arcpy.GetParameterAsText(1)
gdbname=arcpy.ListWorkspaces()
for gdb_Name in gdbname:
  env.workspace = gdb_Name
  for fc in arcpy.ListFeatureClasses():
    gg=arcpy.FeatureClassToFeatureClass_conversion(fc, output, '{}'.format(fc) )

    mm=arcpy.Dissolve_management(fc,gg,"mydissolvefield", "","","")
    arcpy.JoinField_management (mm, "joinfiedl", fc, "joinfield", '#')