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现在完成时用法解析
1.构成
现在完成时是由助动词 have (has)+动词的过去分词构成。助动词说明该谓语是属于现在时范围。它和主语的人称、数要保持一致。过去分词是主要的谓语动词,说明句子的意义。
2.用法
( 1)表示动作发生在过去某个不确定的时间,但对现在留下了某种影响和结果。常被 just、 already、 yet等副词修饰。如:
- Have you had lunch yet? - Yes, I have. I've just had it.
你(已经)吃午饭了吗? 我刚刚吃过。(现在我不饿了)
( 2)表示从过去某一时刻开始一直持续到现在的动作或状态。这个动作可能刚停止,可能仍然在进行。常带有 for和 since等表示一段时间的状语。如: He has taught here since 1981
他自 1981年就在这儿教书。(可能还要继续教)
I have't seen her for four years.
我有四年没见到她了。
( 3)表示说话前发生过一次或多次的动作,现在成为一种经验,一般译为汉语“过”,常带有 twice, ever, never, three times等时间状语。
如: I have been to Beijing twice.我去过北京二次。
3.现在完成时的时间状语
( 1)现在完成时属于现在时范围,故不能和过去的时间状语连用。如: yesterday, last Sunday, in 1990, three years ago等。但是,在强调动作产生的后果和影响时,可以和一些表示不确定的时间状语连用。
a. 用副词 already和 yet。 already一般用于肯定句中, yet一般用于否定句和疑问句中。如: We have already finished our homework.我们已完成作业了。
They haven't finished their homework yet.他们还没有完成作业。
b.用 ever和 never。多用于否定或疑问句中,表示“曾经”或“从未“等。如: - Have you ever been to the Great Wall?你曾经去过长城吗?
- I have never been to the Great Wall.我从未去过长城。
c.用表示到说话为止的过去时间状语,如 just, before, up to now, the past few years等。例如: I have seen her before, but I can not remember where.
我以前见过她,但记不起在哪里见过。
He has been there three times the last few days.
近几年他去过那里三次了。
d.用包括“现在”在内的时间状语,如: now, today, this morning( month, year, term)等。例如: - Have you met him today? - No, I haven't.
今天你见过他吗?我 没有。
How many times have you been there this year?