MySQL CREATE TABLE Statement

MySQL CREATE TABLE Statement

The MySQL CREATE TABLE statement is used to create a new table in an existing database. This statement is essential for defining the structure of a table and specifying its columns and data types.

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Syntax

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

The CREATE TABLE statement has the following components:

• table_name: The name of the table to be created. It must be unique within the database.
• column1, column2, ...: The names of the columns in the table.
• datatype: The data type of the column (e.g., INT, VARCHAR(100), DATE).
• [constraints]: Optional constraints for the column (e.g., PRIMARY KEY, NOT NULL, AUTO_INCREMENT).

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Example MySQL CREATE TABLE Statement

Let's look at an example of the MySQL CREATE TABLE statement:

Step 1: Creating the Table

CREATE TABLE employees (
    id INT AUTO_INCREMENT PRIMARY KEY,
    first_name VARCHAR(50) NOT NULL,
    last_name VARCHAR(50) NOT NULL,
    email VARCHAR(100) UNIQUE
);

This query creates a new table named employees with columns for id, first_name, last_name, and email. The id column is set as the primary key and auto-increments. The first_name and last_name columns cannot be null, and the email column must be unique.

Step 2: Verifying Table Creation

To verify that the table has been created, you can describe the table structure:

DESCRIBE employees;

This query provides a detailed description of the table structure, including column names, data types, and constraints.

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Additional Example: Using IF NOT EXISTS

To create a table only if it does not already exist, use the IF NOT EXISTS option:

CREATE TABLE IF NOT EXISTS employees (
    id INT AUTO_INCREMENT PRIMARY KEY,
    first_name VARCHAR(50) NOT NULL,
    last_name VARCHAR(50) NOT NULL,
    email VARCHAR(100) UNIQUE
);

This query creates the employees table only if it does not already exist, preventing an error if the table already exists.

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Conclusion

The MySQL CREATE TABLE statement is a fundamental tool for defining the structure of tables in a database. Understanding how to use the CREATE TABLE statement and verifying table creation is essential for effective database management in MySQL.