MySQL book borrowing system project database creation TABLE statement (combined primary key and foreign key settings)

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/*
Switch database supperdatabase
*/

use supperdatabase;

SELECT * FROM `supperuser`

Fuzzy query
Be careful % The matching position

select supperuser.address from supperuser where supperuser.address like " Henan %"

select * from supperuser where supperuser.address like " Henan % zheng %"

/*

**

Book borrowing system project database

**
datbases bookdb The specified character set is utf8
*/

create database  bookdb ENGINE=INNODB DEFAULT CHARACTER=utf8;

/*
Get into bookdb Lower operation
*/

use bookdb;

/*
bookinfo ( Book list )
*/

create table  bookinfo(
bookld int primary key default auto_increment COMMENT ' Book number ',
bookName varchar(50)  not null COMMENT ' Book name ',
bookWrite varchar(20) not null COMMENT ' Book author ',
bookContent text not null COMMENT ' Book Introduction ' 
)CHARACTER set=utf8;

/*
borrowInfo ( Loan information sheet )
*/

create table borrowInfo(
borrowld  int primary key auto_increment COMMENT ' Loan No ',
stuName  varchar(20) not null COMMENT ' The student's name ',
clazz  varchar(50) not null COMMENT ' class ',
tel   varchar(11) not null COMMENT ' contact number ',
borrowDate  date not null COMMENT ' Borrowing date ',
returnDate  date COMMENT ' Return date ',
status  int COMMENT ' Return status   The value is 0 or 1 0: Returned books  1: Outstanding books ',
bookld int  COMMENT ' Foreign keys , The number of the book borrowed '
)CHARACTER set=utf8;

/*ENGINE=INNODB DEFAULT CHARACTER=utf8; Set up table The character set is utf8 */

INSERT  into bookinfo VALUES(null," The romance of The Three Kingdoms "," Luo Guanzhong "," From the late Eastern Han Dynasty to the early Western Jin Dynasty ...");
INSERT  into bookinfo VALUES(null," Journey to the west "," Wu chengen "," After the birth of Monkey King and the havoc in heaven ...");
INSERT  into bookinfo VALUES(null," Water margin "," Shi Naian "," Liangshan hero resists oppression ...");
INSERT  into bookinfo VALUES(null," A dream of red mansions "," Cao xueqin "," The rise and fall of the four great families of Jia Shi Wang Xue ...");

INSERT  into borrowInfo VALUES(null," Zhang San ","2020 First class software ",18738171861,"2021-02-01","2021-02-09",0,1);
INSERT  into borrowInfo VALUES(null," Li Si ","2020 Class 2 of level 2 software ",18738171862,"2021-02-03","2021-02-07",0,2);
INSERT  into borrowInfo VALUES(null," Wang Wu ","2020 First class software ",18738171863,"2021-02-09",null,1,3);
INSERT  into borrowInfo VALUES(null," Zhang San ","2020 First class software ",18738171864,"2021-02-10",null,1,4);

/*
Query the table to view the inserted data
*/

select * from bookinfo;

select * from borrowInfo;

bookinfo surface

borrowInfo surface

/*
Set a single primary key for a single table or Without foreign keys
*/

use supperdatabase;

create table t3(
nid int   not null  auto_increment  primary key COMMENT ' Common primary key ' ,
pid int(11)  not   null ,
num int(11)  null
)CHARACTER set=utf8;

insert into t3 values(1,12,123);
insert into t3 values(DEFAULT,122,1234); /*default   The unique constraint is used with autoincrement */
insert into t3 values(DEFAULT,123,12345);

/*
see t3 Table data
*/

 select * from t3;

/*
The settings match (2 individual ) Primary key Foreign keys (2 individual )
*/

create table t1(
nid int(11) not null auto_increment COMMENT' Common primary key ' ,
pid int(11) default null,
num int(11) default null,
primary key (nid,pid)
)CHARACTER set=utf8;

insert into t1 values(DEFAULT,12,123);
insert into t1 values(DEFAULT,123,1234); /*default   The unique constraint is used with autoincrement */
insert into t1 values(DEFAULT,124,12345);

/*
see t1 Table data
*/

select * from t1;

create table t2(
id int(11) not null auto_increment primary key COMMENT ' Common primary key ',
/*pid int(11) default null,*/
id1 int,
id2 int ,
num int(11) default null,
CONSTRAINT fk_t2_t1 foreign  key (id1, id2) references t1(nid, pid) 
)CHARACTER set=utf8;

/*
When the primary foreign key is associated ,
When adding foreign key values It needs to be done according to the primary key value Add... In turn
*/

insert into t2 values(DEFAULT,1,12,DEFAULT);
insert into t2 values(DEFAULT,2,123,DEFAULT); /*default   The unique constraint is used with autoincrement */
insert into t2 values(DEFAULT,3,124,DEFAULT);

/*
see t2 Table data
*/

select *from t2;

/*
see t1 Table structure
*/
desc t1;

/*
see t2 Table structure
*/
desc t2;