Q.Add foreign key in the ATTENDANCE table (use fig. 8.1 to identify referencing and referenced tables).

SQL Table Creation: A First Look

Think of a table as a structured list — the kind you might keep on paper for something you track regularly. A teacher might have a class register: columns for Roll Number, Student Name, and Attendance, with each row being one student's record. That register is a table. SQL (Structured Query Language) is just the language we use to create and manage such tables inside a computer database.

The core idea is simple: a table organises data into rows (records) and columns (fields). Each column holds one type of information — names, dates, amounts — and every row is one complete entry. When you create a table, you are essentially drawing the empty grid and labelling each column with its name and the kind of data it will hold.

The CREATE TABLE Statement

To build a table, you use the CREATE TABLE command. It tells the database: "Make a new empty table with this name and these columns." The basic structure looks like this:

CREATE TABLE table_name (
    column1 datatype,
    column2 datatype,
    column3 datatype
);

You replace table_name with whatever you want to call your table (like Students or Orders). Inside the parentheses, you list each column, followed by its datatype — the kind of data that column will store.

Choosing Datatypes

Every column must have a datatype. This is not a formula or calculation; it is simply a rule that tells the database what sort of information goes in that column. Common datatypes include:

• INT — for whole numbers (like Roll Number or Age)
• VARCHAR(n) — for text of variable length up to n characters (like Name or Address)
• DATE — for dates (like Date of Birth)
• DECIMAL(p,s) — for numbers with decimal places (like Price or Salary)

A Simple Example

Suppose you want to create a table to store information about books in a library. You might write:

CREATE TABLE Books (
    BookID INT,
    Title VARCHAR(100),
    Author VARCHAR(50),
    PublishedYear INT,
    Price DECIMAL(6,2)
);

This creates a table called Books with five columns. BookID will hold whole numbers, Title and Author will hold text (up to 100 and 50 characters respectively), PublishedYear will hold whole numbers, and Price will hold numbers with up to two decimal places. The table is empty — it has no rows yet — but it is ready to accept data.

Why Table Creation Matters …