SQL-选择-外键
我需要选择表VISITSEXIT,当她带来VISITSENTRY时,也会带来idvisitor和idvisitor(visitor)的描述。简单的直截了当会给你想要的:SQL-选择-外键,sql,select,left-join,Sql,Select,Left Join,我需要选择表VISITSEXIT,当她带来VISITSENTRY时,也会带来idvisitor和idvisitor(visitor)的描述。简单的直截了当会给你想要的: VISITSEXIT VISITSENTRY VISITOR idvisitsexit idvisitsentry idvisitor idvisitsentry idvisitante
VISITSEXIT VISITSENTRY VISITOR
idvisitsexit idvisitsentry idvisitor
idvisitsentry idvisitante visitor
idvisitor visitor
visitor
dateexit
timeexit
如果要包含其他表中那些不匹配的行,可能还需要使用左JOIN
。有关JOIN
类型的更多信息,请参阅本文:
SELECT
t.idvisitor,
t.visitor,
t.dateexit,
t.timeext,
... -- the rest of the columns you want to select
FROM VISITSEXIT AS t
INNER JOIN VisitEntry AS e ON t.idvisitentry = e.visitentry
INNER JOIN Visitor AS v ON e.idvisitante = v.idvisitor;