在SQL中联接两个不同的表

Question

Can any one help me find out characterid, firstname, lastname of a killer in Harry potter Schema.

Given a table Character (characterid, firstname, lastname, genderid) and another table Killedby (characterid, killerid, espisode, year) . The Table Character includes information about all characters and in Killedby, the characterid is about the character that was killed.

Answer 1

help me find out characterid, firstname, lastname of a killer in Harry potter Schema

Since a character can be killed only once,i suppose there will be no duplicates,a simple join would suffice.I would recommend reading TSQL 2012 by Itzik Ben-Gan further

select 
ch.characterid, firstname, lastname
from
dbo.charcter ch
join
dbo.killedby kl
on 
ch.characterid=kl.killerid

Answer 2

select Character.characterid, firstname, lastname
from Character, killedby
where killedby.killerid=Character.characterid

The query is straightforward and self-explanatory, but in case of doubt comment indicating your problem.