View Forum Topic

Author Message

Author	Message
yxu22 Posts: 25	Posted 11:57 Nov 12, 2013 \| Hello Professor Sun: Does Q2 only need to implement query like: select dname from dept where did > 20; ? Do we need to implement query : select 5 > 3; and let simpledb return boolean record ? Do we need to implement query : select 'c' > 'a'; ? Last edited by yxu22 at 11:58 Nov 12, 2013.
cysun Posts: 2935	Posted 12:59 Nov 12, 2013 \| Yes for "select dname from dept where did > 20", not for the others. The question is not asking you to significantly expand SimpleDB's SQL grammar. Right now it's `<Term> := <Expression> = <Expression>` and you need to expand it so `<Term> := <Expression> = <Expression> \| <Expression> > <Expression> \| <Expression> < <Expression>` The rest of the grammar remains the same.

yxu22

Posts: 25

Posted 11:57 Nov 12, 2013 |

Hello Professor Sun:

Does Q2 only need to implement query like: select dname from dept where did > 20; ?

Do we need to implement query : select 5 > 3; and let simpledb return boolean record ?

Do we need to implement query : select 'c' > 'a'; ?

Last edited by yxu22 at 11:58 Nov 12, 2013.

cysun

Posts: 2935

Posted 12:59 Nov 12, 2013 |

Yes for "select dname from dept where did > 20", not for the others.

The question is not asking you to significantly expand SimpleDB's SQL grammar. Right now it's

<Term> := <Expression> = <Expression>

and you need to expand it so

<Term> := <Expression> = <Expression> | <Expression> > <Expression> | <Expression> < <Expression>

The rest of the grammar remains the same.