Create a student table and describe the schema of the student table

-
Create a student table and describe the schema of the student table Create a student table and describe the schema of the student table: Rollno number(6), Name varchar(15),
Dept varchar(10), City varchar(15), DOB date, Gender char(1)
QUERY*
create table student (Rollno number(6), Name varchar(15),
 Dept varchar(10), City varchar(15), DOB date, Gender char(1));
Figure 3.1
Fig. 3.1
  • Add foreign key constraint for the column rollno from studmarks that refers rollno from student table.
    • QUERY*
    alter table student add foreign key (Rollno) references stu_marks(Rollno);
    
        desc student;
    Figure 3.2
    Fig. 3.2
  • Remove the column city from the student table.
    • QUERY*
    alter table student drop column City;
    Figure 3.3
    Fig. 3.3

Comments

Post a Comment

Popular posts from this blog

SQL IS NOT NULL.

-
Image
SQL IS NOT NULL Explanation Understanding the SQL IS NOT NULL Condition The IS NOT NULL condition in SQL is used to check for non-null values in a specified column. It helps in filtering the data by excluding rows where the column's value is NULL. Go To Download Examples Consider a database table named Employees with the following columns: Id - Employee's ID Name - Employee's Name Department - Department where the employee works Email - Employee's Email Address To select all employees who have an email address (i.e., where the email address is not null), you would use the following SQL query: SELECT * FROM Employees WHERE Email IS NOT NULL; This query returns all records from the Employees table where the Email column does not contain NULL values. Combining Conditions You can combine IS NOT NULL with other conditions to make more spec
Read more

Database Management System

-
Image
Database Management System Write a query with a function of DDL commands such as create, alter and drop. DDL or Data Definition Language actually consists of the SQL commands that can be used to define the database schema. It simply deals with descriptions of the database schema and is used to create and modify the structure of database objects in the database. DDL is a set of SQL commands used to create, modify, and delete database structures but not data. List of DDL commands: CREATE: This command is used to create the database or its objects (like table, index, function, views, store procedure, and triggers). QUERY: create table bca2 (stu_name varchar(6), stu_roll int, stu_marks number(7)); OUTPUT: DROP: This command is used to delete objects from the database. QUERY: drop table bca2; OUTPUT:
Read more

SQL BETWEEN Operator Example.

-
Image
SQL BETWEEN Operator Example SQL BETWEEN Operator Example The BETWEEN operator in SQL selects values within a given range. The values can be numbers, text, or dates. It is inclusive, which means it includes the beginning and ending values in the range. Example Usage Consider a table named Employees with the following data: ID Name Age 1 John Doe 28 2 Jane Smith 34 3 Emily Johnson 40 To find employees whose ages are between 30 and 35, you would use the following SQL query: SELECT * FROM Employees WHERE Age BETWEEN 30 AND 35; This query will return: ID Name Age 2 ABC Kumar 34
Read more