Inserting Data

INSERT INTO

The INSERT INTO statement adds new rows to a table.

Basic Insert

INSERT INTO products (name, price, category, stock)
VALUES ('USB Hub', 29.99, 'Electronics', 100);

You list the columns, then the corresponding values in the same order. Columns with DEFAULT values or AUTO_INCREMENT can be omitted.

Inserting Without Column Names

If you provide values for every column in order, you can omit the column list:

INSERT INTO products VALUES (11, 'USB Hub', 29.99, 'Electronics', 100);

This is fragile — if you add a column later, this query breaks. Always prefer the explicit column list.

Multi-Row Insert

MySQL can insert multiple rows in one statement, which is much faster than separate INSERT statements:

INSERT INTO products (name, price, category, stock)
VALUES
  ('USB Hub', 29.99, 'Electronics', 100),
  ('Mouse Pad', 9.99, 'Accessories', 250),
  ('Webcam', 89.99, 'Electronics', 45);

INSERT IGNORE

If a row violates a unique constraint, INSERT IGNORE silently skips it instead of throwing an error:

INSERT IGNORE INTO customers (id, name, email, city)
VALUES (1, 'Alice', 'alice@example.com', 'New York');
-- If id=1 already exists, this is silently ignored

INSERT ... ON DUPLICATE KEY UPDATE

This is MySQL's upsert syntax — insert a row, or update it if a duplicate key is found:

INSERT INTO products (id, name, price, category, stock)
VALUES (1, 'Laptop', 999.99, 'Electronics', 60)
ON DUPLICATE KEY UPDATE stock = stock + 10;
-- If id=1 exists, updates stock instead of inserting

LAST_INSERT_ID()

After inserting a row with AUTO_INCREMENT, retrieve the generated id:

INSERT INTO customers (name, email, city)
VALUES ('Frank', 'frank@example.com', 'Seattle');

SELECT LAST_INSERT_ID();  -- Returns the auto-generated id

Inserting from SELECT

You can insert data selected from another table:

INSERT INTO archive_customers (name, email, city)
SELECT name, email, city FROM customers WHERE city IS NULL;

Your Task

Insert a new product into the products table:

• name: 'USB Hub'
• price: 29.99
• category: 'Electronics'
• stock: 100