Q.Write SQL statements to

This asks you to use DDL commands: create a database, select it, and then create a table with suitable data types and a primary key.

CREATE DATABASE SchoolDB;
USE SchoolDB;
CREATE TABLE Student (
    RollNo INT PRIMARY KEY,
    Name VARCHAR(50),
    Class VARCHAR(10),
    Marks INT
);

These are three DDL jobs done one after another.

(i) Create the database with CREATE DATABASE:

CREATE DATABASE SchoolDB;

(ii) Select it with USE, so that the following commands act on SchoolDB:

USE SchoolDB;

(iii) Create the table with CREATE TABLE, listing each field and its data type. A whole number uses INT; text of up to n characters uses VARCHAR(n); the identifying field is marked PRIMARY KEY.

• RollNo — whole number and primary key → RollNo INT PRIMARY KEY
• Name — text up to 50 characters → Name VARCHAR(50)
• Class — text up to 10 characters → Class VARCHAR(10)
• Marks — whole number → Marks INT

CREATE TABLE Student (
    RollNo INT PRIMARY KEY,
    Name VARCHAR(50),
    Class VARCHAR(10),
    Marks INT
);

After these statements, SchoolDB contains an empty Student table ready for records. Note that keywords are capitalised by convention and every statement ends with a semicolon.

CREATE DATABASE SchoolDB;
USE SchoolDB;
CREATE TABLE Student (
    RollNo INT PRIMARY KEY,
    Name VARCHAR(50),
    Class VARCHAR(10),
    Marks INT
);

Common errors: forgetting the USE statement (so the table is created in the wrong or no database), forgetting the semicolon at the end of each statement, omitting the length in VARCHAR (write VARCHAR(50), not VARCHAR), and forgetting to mark the PRIMARY KEY.