在第3个表中使用外键使用第一个表数据的语法是什么,假设有3个表 [英] what is the syntax to use foreign key in 3rd table to use first table data,suppose there is 3 table
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问题描述
创建 数据库 muni
使用 muni
创建 table stream
(
streamname varchar ( 10 )约束 stream_strname_pk primary key
)
select * from stream
create table branch
(
branchid int identity 约束 branch_bid_pk primary key ,
branchname varchar ( 20 )不 null ,
streamname varchar ( 10 )约束 stream_strname_fk 外来 key references stream(streamname)
)
select *来自分支机构
创建 表 semistar
(
semistarid int identity 约束 semistar_sid_pk primary key ,
semistarname varchar (< span class =code-digit> 30 )不 null ,
streamname varchar ( 10 )约束 stream_stname_fk foreign key references stream(stramname)
)
选择 *来自semistar
解决方案
我认为你在这一行中犯了一个简单的错误:
streamname varchar ( 10 )约束 stream_stname_fk 外来 key 参考 stream( stramname )
它应该是:
streamname varchar ( 10 )约束 stream_stname_fkforeign key references stream( streamname )
create database muni
use muni
create table stream
(
streamname varchar(10) constraint stream_strname_pk primary key
)
select *from stream
create table branch
(
branchid int identity constraint branch_bid_pk primary key,
branchname varchar(20) not null,
streamname varchar(10) constraint stream_strname_fk foreign key references stream(streamname)
)
select *from branch
create table semistar
(
semistarid int identity constraint semistar_sid_pk primary key,
semistarname varchar(30) not null,
streamname varchar(10)constraint stream_stname_fk foreign key references stream(stramname)
)
select *from semistar
解决方案
Hi,
I think that you have a made a simple mistake in this line:
streamname varchar(10)constraint stream_stname_fk foreign key references stream(stramname)
It should be:
streamname varchar(10)constraint stream_stname_fk foreign key references stream(streamname)
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