How to generate a UUID in PostgreSQL for insert statements?
Generating a UUID in PostgreSQL for an insert statement
In PostgreSQL, a UUID (Universally Unique Identifier) is often used as a primary key or unique identifier due to its globally unique property. PostgreSQL has built-in support for UUIDs, making it easy to generate them within an INSERT statement. Using a UUID provides a unique, non-sequential identifier that is useful in distributed systems or when a unique identifier is required.
Enabling the uuid-ossp Extension
To generate UUIDs in PostgreSQL, you need to enable the uuid-ossp extension, which provides functions for UUID generation. Run the following command to enable it:
CREATE EXTENSION IF NOT EXISTS "uuid-ossp";
Syntax for Generating a UUID during insert:
With the uuid-ossp extension enabled, you can use the uuid_generate_v4() function to generate a random UUID in your INSERT statement.
INSERT INTO table_name (id, column1, column2, ...) VALUES (uuid_generate_v4(), value1, value2, ...);
Explanation:
- table_name: Name of the table where you are inserting data.
- uuid_generate_v4(): Generates a random UUID.
- (column1, column2, ...): Columns in the table.
- (value1, value2, ...): Values corresponding to each column.
Example Code and Explanation:
Suppose you have a table called products, where product_id is the UUID primary key. Here’s how you can insert a new product with an auto-generated UUID.
1. Enable the uuid-ossp Extension
Code:
-- Enable the uuid-ossp extension for UUID generation CREATE EXTENSION IF NOT EXISTS "uuid-ossp";
2. Insert with a Generated UUID
Code:
-- Insert a new row with a randomly generated UUID for product_id INSERT INTO products (product_id, name, price) VALUES (uuid_generate_v4(), 'Gadget Pro', 299.99);
Explanation:
- CREATE EXTENSION IF NOT EXISTS "uuid-ossp": Ensures the UUID extension is enabled.
- INSERT INTO products (product_id, name, price): Specifies the table and columns for the insert.
- uuid_generate_v4(): Generates a unique UUID for the product_id.
- 'Gadget Pro', 299.99: Sample values for name and price.
Using UUIDs with Default Values
You can also set a UUID as the default value for a column in table creation, ensuring every row gets a unique identifier automatically.
Code:
-- Create a table with a UUID as the default for product_id
CREATE TABLE orders (
order_id UUID DEFAULT uuid_generate_v4() PRIMARY KEY,
customer_name VARCHAR(100),
total_amount DECIMAL(10, 2)
);
In this case, you can insert data without specifying the order_id, and it will automatically generate a UUID.
-- Insert a new order with auto-generated UUID for order_id
INSERT INTO orders (customer_name, total_amount)
VALUES ('Jane Doe', 500.00);
Important Notes:
- UUID Version: uuid_generate_v4() creates random UUIDs (version 4). PostgreSQL also supports other UUID versions for specific use cases.
- Performance: UUIDs are ideal for distributed systems but can impact indexing performance compared to sequential integers.
It will be nice if you may share this link in any developer community or anywhere else, from where other developers may find this content. Thanks.
https://w3resource.com/PostgreSQL/snippets/generating-uuid-for-insert-statement-postgresql.php
- Weekly Trends and Language Statistics
- Weekly Trends and Language Statistics