有3张表如下:
create table Quote
(
ID int primary key,
ContactID int,
Info varchar(1000),
CreateDate datetime
)create table Contact
(
ContactID int primary key,
CompanyID int
)create table Company
(
CompanyID int primary key,
CompanyName varchar(30)
)查询的结果是Quote表里的内容加上ContactID所在的公司名
ID ContactID CompanyName Info CreateDate
-----------------------------------------
create table Quote
(
ID int primary key,
ContactID int,
Info varchar(1000),
CreateDate datetime
)create table Contact
(
ContactID int primary key,
CompanyID int
)create table Company
(
CompanyID int primary key,
CompanyName varchar(30)
)查询的结果是Quote表里的内容加上ContactID所在的公司名
ID ContactID CompanyName Info CreateDate
-----------------------------------------
from Quote a, Contact b,Company c
where a.ContactID=b.ContactID and
b.CompanyID=c.CompanyID
select Q.ID, Q.ContactID, Com.CompanyName, Q.Info, Q.CreateDate
from Quote Q join Contact C on Q.ContactID=C.ContactID
join Company Com on C.CompanyID=Com.CompanyID
from Quote Q join Contact C on Q.ContactID=C.ContactID
join Company Com on C.CompanyID=Com.CompanyID