1. Create, edit, and delete data tables in Management Studio;
2. Create, edit, and delete data tables using T-SQL;

T-SQL statement creation table structure

The table structure is as follows, based on the structure of the data table.
student:

Field Name	Field type and length	Description	Note
sno	char（9）	Student number	Main keyword
sname	nvarchar（6）	student name	non empty
ssex	nchar（1）	Student gender	Can be empty
sage	int	Student age	Can be empty
sdept	nvarchar（8）	Student office department	Can be empty

code show as below:

use student
create table student(
sno char(9) not null primary key,
sname nvarchar(6) not null,
ssex nchar(1),
sage int,
sdept nvarchar(8)
)

Course (Course Information Table):

Field Name	Field type and length	Description	Note
cno	char（4）	Course No	Main keyword
cname	nvarchar（20）	Course Title	non empty
cpno	char（4）	First class	Can be empty
ccredit	int	credit	Can be empty

code show as below:

use student
create table course(
cno char(4) not null primary key,
cname nvarchar(20) not null,
cpno nchar(4),
ccredit int null,
)

SC (selection information table):

Field Name	Field type and length	Description	Note
sno	char（9）	Student number	Main keyword
cno	char（4）	Course No	Main keyword
grade	int	Grade	Can be empty

code show as below:

use student
create table sc(
sno char(9) not null,
cno char(4) not null,
grade int,
primary key ( sno, cno )
)

T-SQL statement modification table structure

(1) Add a new field "Class Name (Sclass)" character type to VARCHAR (10) in Table Student.

use student
alter table student 
add sclass vachar(1o)

(2) Remove field "Sclass" in Table Student;

use student
alter table student 
drop column sclass

(3) Modify the field length of the field name "sname" in the table Student is changed from the original 6 to 8;

use student
alter table student 
alter column snmae nvarchar(8)

Operation prompt

Create a table

(1) Steps in the management interface method:

Open the small plus number in front of the database name that has been created, right-click on the [Table] node, select the [New Table] command to open the watch designer window. Enter the column name in the table designer window. Select the data type and whether it is allowed to be empty, and click the right mouse button in front of the primary key field, select [Set Primary Key] option. It is also possible to identify the meaning of each field representation in the description of the column properties. After the design is complete, press the CTRL + S key button to save, enter the table name in the pop-up dialog box, click the [OK] button.

(2) Steps in the T-SQL statement method:

On the [SQL Server Management Studio] window, select the [New Query] button to start the SQL Editor window, enter the T-SQL statement at the cursor, click the [Execute] button.

2. Modify the table structure

(1) Steps in the management interface method:

On the table student you need to modify, right-click, select the [Designer] command, open [Table Designer], modify it in the need to modify, click the [Save] button after the modification is complete.

(2) Steps in the T-SQL statement method:

On the [SQL Server Management Studio] window, select the [New Query] button to start the SQL Editor window, enter the T-SQL statement at the cursor, click the [Execute] button.