Question

有人可以解释，加入多个带别名的表吗？

我无法让代码工作......继续给我错误＆＃34;无法绑定＆＃34;此错误消息适用于以下内容：M.ZipCode，C.Member_ID，F.Navn，F.Navn（最后一个）。我对SQL仍然很陌生，我知道我搞砸了Zipcode的名字。澄清我有一个名为Zipcode的表，其中包含Zipcodes，成员在成员表中需要一个zipcode。

SELECT
  m.Fornavn,
  m.Efternavn,
  m.Zipcode,
  z.City,
  c.Model,
  c.Producent,
  s.Navn,
  s.Antal,
  s.Pris
FROM Members M, Fabricator F, Cars C, Storage S, ZipCode Z
  INNER JOIN Members ON Z.Zipcode = M.ZipCode AND C.Member_ID = Members.ID
  INNER JOIN Cars ON F.Navn = Cars.Producent
  INNER JOIN Storage ON F.Navn = Storage.Producent;

Answer 1

你可能意味着

SELECT
m.Fornavn,
m.Efternavn,
m.Zipcode,
z.City,
c.Model,
c.Producent,
s.Navn,
s.Antal,
s.Pris 
FROM Fabricator F
INNER JOIN Cars C ON F.Navn = C.Producent
INNER JOIN Members M ON C.Member_ID = M.ID
INNER JOIN ZipCode Z  ON Z.Zipcode = M.ZipCode
INNER JOIN Storage S ON F.Navn = S.Producent

Answer 2

您似乎需要以下FROM子句：

FROM ZipCode z INNER JOIN
     Members m
     ON z.Zipcode = m.ZipCode INNER JOIN
     Cars c
     ON c.Member_ID = m.ID INNER JOIN
     Fabricator f
     ON f.Navn = c.Producent INNER JOIN
     Storage s
     ON f.Navn = s.Producent

FROM子句中的逗号表示CROSS JOIN - 笛卡尔积。您有多次提到的相同表。最简单的方法是学习使用正确的语法。

Answer 3

FROM M，Fabricator F，Cars C，Storage S，ZipCode Z

是CROSS JOIN的简短形式，所以你必须避免使用这种表示法，据我所知它是不推荐使用的表示法

SQL使用别名连接多个表

3 个答案: