1. Create a relational database S_T###,

The database character set is required to be utf8, and the character set collation rules are default.

Note: ### in the database name represents the last three digits of my student number. For example, Zhang Hua's student number is 20160714121, and his database name is "S_T121"

Specific operation:

Right-click MySQL and select New-Schema

2. In the S_T database, create the student table students

The storage engine of this table is InnoDB, using the default character set of the database. This table mainly includes four attributes: student number (sno), name (sname), date of birth (sbirth) and grade (grade). The data type, length and constraint requirements of each attribute are as follows:

Sno: char(10), main code;

Sname: char(4), not allowed to be empty

sbirth：date，

Grade：smallint。

Specific operation:

Right-click the database, select New - Table

The first step, custom table name

The second step, add a new column

The third step, custom column

final display

The syntax in the red box means that the storage engine of the table is InnoDB, and the default character set of the database is used. It’s okay not to write, because the default is the InnoDB storage engine

Note: the primary key cannot be empty

Syntax used:

CREATE TABLE `students` (
  `Sno` char(10) NOT NULL,
  `Sname` char(4) NOT NULL,
  `sbirth` date DEFAULT NULL,
  `Grade` smallint(6) DEFAULT NULL,
  PRIMARY KEY (`Sno`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

3. In the S_T database, create the teacher table Teachers

It mainly includes four attributes: teacher number (Tno), teacher name (Tname), gender (sex) and salary (salary). The data type, length and constraint requirements of each attribute are as follows:

Tno:CHAR(8) , main code;

Tname: char(4) not-null constraint,

sex: compound type, the value is 'male' or 'female',

Salary：float。

Concrete operation

Same as creating the students table

Note that the definition of sex compound type

syntax used

CREATE TABLE `teachers` (
  `Tno` char(8) NOT NULL,
  `Tname` char(4) NOT NULL,
  `sex` enum('男','女') DEFAULT NULL,
  `Salary` float DEFAULT NULL,
  PRIMARY KEY (`Tno`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

4. In the S_T database, create the curriculum table Courses

It mainly includes three attributes: class number (Cno), class name (Cname) and class hour (Chour). The data type, length and constraint requirements of each attribute are as follows:

Cno: char(8) not-null constraint,

cname: varchar(10) not-null constraint,

Chour：tinyint。

Concrete operation

syntax used

create table Courses
(
    Cno   char(8)     not null,
    cname varchar(10) not null,
    Chour tinyint     null
);

type	size	range (signed)	range (unsigned)	use
TINYINT	1 Bytes	(-128，127)	(0，255)	small integer value

type	size	use
CHAR	0-255 bytes	fixed length string
VARCHAR	0-65535 bytes	variable length string

5. In the S_T database, create a course selection table STC

It includes four attributes: Student ID (Sno), Teacher ID (Tno), Class ID (Cno) and Grade (score). The data type, length and constraint requirements of each attribute are as follows:

Sno：char(10)，

Cno:CHAR(8),

Tno:CHAR(8)，

Score：int。

Set (Sno, cno) as the main code, and the Sno attribute in the STC table is the external code, refer to the student number sno in the students table.

Concrete operation

When setting two attributes to combine into a primary key, you need to add attributes in the operation of the key

When setting a foreign key: enter the foreign key operation

1. Select the target table

2. Add foreign key column

6. Modify the Students table with a statement,

Add the gender Ssex attribute after the sname attribute, which is an enum type and can only be "male" or "female";

Concrete operation

Right-click the students table and enter the query console

ALTER TABLE students 
    ADD Ssex enum('男','女') AFTER Sname;

Successfully displayed after execution

7. Change the score in the STC table to smallint type by modifying the statement;

see operation

ALTER TABLE stc
    MODIFY Score smallint;

When modifying existing properties, use the MODIFY keyword

8. Set the Cno attribute in the Course table as the main code.

see operation

ALTER TABLE courses
    ADD PRIMARY KEY (Cno);

To add a primary key to an existing attribute, use the ADD keyword

9. Add referential integrity constraints for cno in the STC table, and refer to the Cno attribute in the Courses table.

see operation

alter table stc
    add foreign key (Cno)references courses(Cno);

Grammar explanation: modify the table stc, add a primary key Cno, refer to the Cno in the courses table

10. Enter the data in the following table into the four tables that have been created.

Students table:

sno	takes off	Ssex	breath	grade
201615121	Li Li	female	1999-1-1	2016
201615122	Wang Yang	male	1998-12-21	2016
201615123	Liu Chen	female	1998-6-5	2016
201715121	Wang Xiaochen	male	1999-4-16	2017
201715122	Zhang Fang	male	1997-6-1	2017
201715123	Qiao Yunping	female	1999-8-12	2017

Teachers table:

Tno	Tname	Sex	salary
101	Li Dawei	male	6200
102	Liu Yun	female	4500
103	Wang Jun	male	3600
104	Zhang Hongxia	female	4100

Course ScheduleCourses

Cno	Cname	Choir
B001	advanced mathematics	80
B002	Introduction to Computer	48
B003	C programming	64
B004	data structure	72
B005	Database systems	56
B006	fuzzy mathematics	56

Class ScheduleSTC

Sno	Cno	Tno	score
201615121	B001	101	78
201615121	B002	102	85
201615121	B003	103	69
201615121	B004	104
201615122	B002	102	98
201615122	B003	103	89
201615123	B001	101	65
201615123	B003	103	56
201615123	B004	104
201715121	B002	102	68
201715121	B004	104	78
201715123	B001	101	81
201715123	B002	102	60

Concrete operation

The method I choose is to copy the data to an Excel table

Plus sign, add row, select the first cell

Then copy the data in the Excel table and paste it into the first cell

Experiment 1 database, table creation and maintenance

This article records database and table creation and maintenance related operations, including client interface operation methods and command operation methods

Experimental environment: MySQL 5.7, DataGrip

1. Purpose of the experiment

2. Experiment content (please complete the following operations)

1. Create a relational database S_T###,

Specific operation:

2. In the S_T database, create the student table students

Specific operation:

Syntax used:

3. In the S_T database, create the teacher table Teachers

Concrete operation

syntax used

4. In the S_T database, create the curriculum table Courses

Concrete operation

syntax used

5. In the S_T database, create a course selection table STC

Concrete operation

6. Modify the Students table with a statement,

Concrete operation

7. Change the score in the STC table to smallint type by modifying the statement;

see operation

8. Set the Cno attribute in the Course table as the main code.

see operation

9. Add referential integrity constraints for cno in the STC table, and refer to the Cno attribute in the Courses table.

see operation

10. Enter the data in the following table into the four tables that have been created.

Concrete operation

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