CREATE TABLE

The CREATE TABLE statement is used to create a new table in a database. A table is a collection of related data organized in rows and columns.

Syntax

CREATE TABLE table_name (
    column1 datatype [constraint],
    column2 datatype [constraint],
    ...
);

Explanation

• table_name – The name of the table you want to create.
• column1, column2, … – Names of the columns in the table.
• datatype – Type of data the column can hold (e.g., INT, VARCHAR, DATE).
• constraint – Optional rules for the column, such as PRIMARY KEY, NOT NULL, UNIQUE.

Common Data Types

• INT – Whole numbers
• VARCHAR(size) – Text with a maximum length
• DATE – Date values
• FLOAT – Decimal numbers

Common Constraints

• PRIMARY KEY – Uniquely identifies each row
• NOT NULL – Ensures the column cannot have empty values
• UNIQUE – Ensures all values in the column are unique
• FOREIGN KEY – Links a column to a column in another table

Example

CREATE TABLE Students (
    StudentID INT PRIMARY KEY,
    FirstName VARCHAR(50) NOT NULL,
    LastName VARCHAR(50) NOT NULL,
    BirthDate DATE,
    Email VARCHAR(100) UNIQUE
);

Explanation of Example

• StudentID – Integer column and primary key
• FirstName and LastName – Text columns that cannot be empty
• BirthDate – Stores the student’s date of birth
• Email – Stores student email and must be unique