The MySQL DESCRIBE TABLE
statement is used to provide detailed information about the structure of a table. This statement is essential for understanding the schema of a table, including its columns, data types, and constraints.
DESCRIBE table_name;
The DESCRIBE TABLE
statement has the following component:
table_name
: The name of the table whose structure is to be described.Let's look at an example of the MySQL DESCRIBE TABLE
statement and how to use it:
USE mydatabase;
This query sets the context to the database named mydatabase
.
Create a table to work with:
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 table named employees
with columns for id
, first_name
, last_name
, and email
.
Describe the table to get its structure:
DESCRIBE employees;
This query provides a detailed description of the employees
table, including column names, data types, and constraints.
The output of the DESCRIBE
statement includes the following information:
Field
: The name of the column.Type
: The data type of the column.Null
: Whether the column can contain NULL values.Key
: Whether the column is indexed (e.g., PRI
for primary key).Default
: The default value of the column.Extra
: Any additional information (e.g., auto_increment
).This output provides detailed information about each column in the employees
table.
The MySQL DESCRIBE TABLE
statement is a powerful tool for understanding the structure of tables. Knowing how to use the DESCRIBE TABLE
statement is essential for effective database management and schema design in MySQL.