select t.*, t.rowid from portal_cvmspt_extra_bill t

1 将修改的字段置空
update portal_cvmspt_extra_bill t set t.tip_message = [color=red]null[/color]

2 设置将需要修改的字段
alter table portal_cvmspt_extra_bill  modify [color=green]tip_message [/color][color=red]NUMBER(2)[/color]