Unknown column "_seen"

unknown column “_seen” in field list during on table append condition with save method
pls anyone tell me how to resolve this…

You need to provide a lot more information about the context of this issue.

I tried like this below code tat time shown unknown column _seen in field list
so, i removed repeat_table.save() this err not shown i dont know what is the pblm in save() why its shown unknowm column error

                    repeat_table = self.append('deviation_repeat', {})
					repeat_table.previous_deviation_no = i.name
					repeat_table.date_of_previous_deviation = i.plan_date
					repeat_table.deviation_closed = i.plan_closed_date

hi all i got solution append condition not need save() so now its working fine thanks for ur rly…