SQL CREATE TABLE and INSERT INTO Explained, with Practice

# Create a new table You need it whenever a project has something new to store, like delivery drivers. Every table you have queried so far began with a CREATE TABLE. CREATE TABLE makes a new, empty table. Give it a name, then list its columns in brackets: each column's name and the type of data it holds. - `CREATE TABLE drivers` make a table called drivers - `(id INT, name VARCHAR(50), …)` its columns, separated by commas - `INT` `VARCHAR` `DECIMAL` data types: the next slide explains them - `;` ends one statement, so the next one can start - `DESCRIBE drivers` lists the table's columns and their types > Use lower-case names with underscores, like added_on. Spaces or capitals in a name force you to quote it in every query.

CREATE TABLE drivers (
  id INT,
  name VARCHAR(50),
  rating DECIMAL(3,1));
DESCRIBE drivers

# Data types Every column holds one type of data. - `INT` whole numbers: 1, 2, 3 - `VARCHAR(30)` text, up to 30 characters - `DECIMAL(4,2)` exact numbers with decimals: 4 digits, 2 after the point, like 11.25 - `DATE` a day, like '2026-10-23' - `BOOLEAN` yes or no; MySQL stores it as TINYINT(1), 0 or 1 > Use DECIMAL for money, never FLOAT. FLOAT stores approximations, so 0.1 + 0.2 doesn't come out as exactly 0.3.

CREATE TABLE toppings (
  id INT,
  name VARCHAR(30),
  price DECIMAL(4,2),
  added_on DATE,
  vegan BOOLEAN
);
DESCRIBE toppings

# Required columns and defaults - `NOT NULL` this column must always have a value - `DEFAULT 5.0` the value used when an INSERT leaves the column out Leave a NOT NULL column empty and the database refuses with "NOT NULL constraint failed". A constraint is a rule the database enforces. > Make a column NOT NULL whenever a row makes no sense without it. It's far easier than cleaning up empty values later.

CREATE TABLE drivers (
  id INT,
  name VARCHAR(50) NOT NULL,
  rating DECIMAL(3,1) DEFAULT 5.0
);
DESCRIBE drivers

# Add rows: INSERT INTO - `INSERT INTO drivers (id, name, rating)` the table, then the columns you are filling - `VALUES (1, 'Zoe', 4.8), (2, 'Max', 4.2)` the values in the same order, one pair of brackets per row A column you leave out gets its DEFAULT, or NULL. You can skip the column list, INSERT INTO drivers VALUES (4, 'Bo', 4.9), but then you must give every column, in the table's order. > Always list the columns. If someone adds a column to the table later, an INSERT without a column list breaks.

CREATE TABLE drivers (
  id INT,
  name VARCHAR(50) NOT NULL,
  rating DECIMAL(3,1) DEFAULT 5.0
);
INSERT INTO drivers (id, name,
  rating)
VALUES (1, 'Zoe', 4.8),
  (2, 'Max', 4.2);
INSERT INTO drivers (id, name)
VALUES (3, 'Ali');
SELECT * FROM drivers

# INSERT into an existing table INSERT works the same way on any table. This one adds a new pizza to the menu. > After an INSERT, SELECT the new row by its id to check what went in.

INSERT INTO pizzas (id, name, price,
  spicy, veg)
VALUES (9, 'Truffle Shuffle', 15,
  0, 1);
SELECT * FROM pizzas WHERE id = 9