sql - 从多个表中进行 SQL SELECT

Question

如何从customers1 和customers2 获取所有产品，包括他们的客户名称？

customer1 table
cid name1
1   john
2   joe

customer2 table
cid name2
p1  sandy
p2  linda

product table
pid cid pname
1   1   phone
2   2   pencil
3   p1  pen
4   p2  paper

结果应该是这样的

pid  cid  pname  name1 name2
1    1    phone  john  NULL
2    2    pencil joe   NULL
3    p1   pen    NULL  sandy
4    p2   paper  NULL  linda

Answer 1

SELECT p.pid, p.cid, p.pname, c1.name1, c2.name2
FROM product p
LEFT JOIN customer1 c1 ON p.cid = c1.cid
LEFT JOIN customer2 c2 ON p.cid = c2.cid

Answer 2

SELECT pid, cid, pname, name1, name2 
FROM customer1 c1, product p 
WHERE p.cid=c1.cid 
UNION SELECT pid, cid, pname, name1, name2 
FROM customer2 c2, product p 
WHERE p.cid=c2.cid;

Answer 3

SELECT `product`.*, `customer1`.`name1`, `customer2`.`name2`
FROM `product`
LEFT JOIN `customer1` ON `product`.`cid` = `customer1`.`cid`
LEFT JOIN `customer2` ON `product`.`cid` = `customer2`.`cid`

Answer 4

select p.pid, p.cid, c1.name,c2.name
from product p
left outer join customer1 c1 on c1.cid=p.cid
left outer join customer2 c2 on c2.cid=p.cid

Answer 5

SELECT 
  pid, 
  cid, 
  pname, 
  name1, 
  null 
FROM 
  product p
INNER JOIN 
  customer1 c ON p.cid = c.cid
UNION
SELECT 
  pid, 
  cid, 
  pname, 
  null, 
  name2
FROM 
  product p
INNER JOIN 
  customer2 c ON p.cid = c.cid

Answer 6

SELECT p.pid, p.cid, p.pname, c1.name1, c2.name2
FROM product AS p
    LEFT JOIN customer1 AS c1
        ON p.cid = c1.cid
    LEFT JOIN customer2 AS c2
        ON p.cid = c2.cid

Answer 7

我想我已经从 7 个表中加入了这样的人

SELECT a.no_surat , 
a.nm_anggota , 
a.nrp_nip_anggota , 
a.tmpt_lahir , 
a.tgl_lahir , 
a.bln_lahir , 
a.thn_lahir , 
a.alamat , 
a.keperluan , 
a.nm_jabatan , 
b.id_polsek ,b.nm_polsek, 
c.id_polres ,c.nm_polres , 
d.id_pangkat , d.nm_pangkat, 
e.id_pejabat , e.nm_pejabat , 
f.id_ket , f.nm_ket, 
g.id_pejabat,g.nm_pejabat 
FROM tbl_skhp AS a 
LEFT JOIN tbl_polsek AS b ON a.id_polsek=b.id_polsek 
LEFT JOIN tbl_polres AS c ON a.id_polres=c.id_polres 
LEFT JOIN tbl_pangkat AS d ON a.id_pangkat=d.id_pangkat
LEFT JOIN tbl_pejabat AS e ON a.id_pejabat=e.id_pejabat
LEFT JOIN tbl_ket AS f ON a.id_ket=f.id_ket 
LEFT JOIN tbl_pejabat AS g ON a.id_pejabat=g.id_pejabat

我希望你明白....我只是为我分享工作代码....我用它来获取数据到我的只读表单中，只是为了 priview...