INSERT INTO Statement
Adding Data to SQL Tables

Introduction

Tables are like empty registers — they need entries to become useful. That’s where the INSERT INTO statement steps in. It lets you add rows of meaningful data into your SQL tables — student records, teacher assignments, exam scores — all start here.

Syntax of INSERT INTO

Standard Syntax

INSERT INTO table_name (column1, column2, ...)
VALUES (value1, value2, ...);

Short Syntax (Only when inserting all columns in order)

INSERT INTO table_name
VALUES (value1, value2, ...);

1. Basic INSERT Example

Assume we already created a students table:

CREATE TABLE students (
  roll_no INT PRIMARY KEY,
  name VARCHAR(50),
  class VARCHAR(10),
  age INT,
  city VARCHAR(30)
);

Now let’s insert data for a student named Arjun:

INSERT INTO students (roll_no, name, class, age, city)
VALUES (1, 'Arjun Deshmukh', '10A', 15, 'Pune');

2. Inserting Multiple Records

Rather than inserting one record at a time, you can insert many in a single statement:

INSERT INTO students (roll_no, name, class, age, city)
VALUES
(2, 'Priya Reddy', '9B', 14, 'Hyderabad'),
(3, 'Karan Mehta', '10A', 15, 'Ahmedabad'),
(4, 'Neha Iyer', '8C', 13, 'Chennai');

3. Viewing Inserted Data

SELECT * FROM students;

roll_no | name            | class | age | city
--------+-----------------+-------+-----+-----------
1       | Arjun Deshmukh  | 10A   | 15  | Pune
2       | Priya Reddy     | 9B    | 14  | Hyderabad
3       | Karan Mehta     | 10A   | 15  | Ahmedabad
4       | Neha Iyer       | 8C    | 13  | Chennai

4. Inserting Only Specific Columns

If you don't have data for all columns, you can skip them — but you must exclude them in the column list as well:

INSERT INTO students (roll_no, name, class)
VALUES (5, 'Devanshi Shah', '9A');

5. What If You Miss Required Columns?

Let’s try inserting without specifying roll_no (which is PRIMARY KEY):

INSERT INTO students (name, class, age, city)
VALUES ('Ishaan Pandey', '10B', 15, 'Lucknow');

ERROR: Column 'roll_no' cannot be null

This teaches an important lesson — columns marked NOT NULL or PRIMARY KEY must always be provided.

6. INSERT with DEFAULT Values

Suppose we create a student_profile table with a default city:

CREATE TABLE student_profile (
  roll_no INT PRIMARY KEY,
  name VARCHAR(50),
  city VARCHAR(30) DEFAULT 'Delhi'
);

Now insert without specifying the city:

INSERT INTO student_profile (roll_no, name)
VALUES (1, 'Mehul Arora');

roll_no | name         | city
--------+--------------+-------
1       | Mehul Arora  | Delhi

Best Practices for INSERT INTO

• Always specify column names for clarity and future safety.
• Validate data types — inserting text into a number column will cause errors.
• Insert in batches if you have many records.

Summary

The INSERT INTO statement breathes life into your tables. It’s how raw data makes its way into a structured format. Whether it’s a new student enrolment or exam result, everything starts here.

What’s Next?

Next up, we’ll explore the SELECT statement — your primary tool for fetching data and making sense of the entries you've just inserted.