Add unique identifiers to your tables

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Generate UUIDs for automatic row identification.

Problem

You need unique identifiers for rows in your data pipeline. Maybe you’re building an API that returns specific records, tracking processing status across systems, or joining data from multiple sources.

Solution

What’s in this recipe:

Create tables with auto-generated UUID primary keys
Add UUID columns to existing tables
Generate UUIDs with uuid7()

You use uuid7() to generate UUIDs for each row. Define it in the schema with {'column_name': uuid7()} syntax, or add it to existing tables with add_computed_column().

Setup

%pip install -qU pixeltable

import pixeltable as pxt
from pixeltable.functions.uuid import uuid7

# Create a fresh directory
pxt.drop_dir('uuid_demo', force=True)
pxt.create_dir('uuid_demo')

Create a table with a UUID primary key

Use uuid7() in your schema to create a column that auto-generates UUIDs:

# Create table with auto-generated UUID primary key
products = pxt.create_table(
    'uuid_demo/products',
    {
        'id': uuid7(),  # Auto-generates UUID for each row
        'name': pxt.String,
        'price': pxt.Float,
    },
    primary_key=['id'],
)

Created table ‘products’.

# Insert data - no need to provide 'id', it's auto-generated
products.insert(
    [
        {'name': 'Laptop', 'price': 999.99},
        {'name': 'Mouse', 'price': 29.99},
        {'name': 'Keyboard', 'price': 79.99},
    ]
)

Inserted 3 rows with 0 errors in 0.02 s (191.21 rows/s)
3 rows inserted.

# View the data - each row has a unique UUID
products.collect()

Add a UUID column to an existing table

You can add a UUID column to a table that already exists using add_computed_column():

# Create a table without a UUID column
orders = pxt.create_table(
    'uuid_demo/orders', {'customer': pxt.String, 'amount': pxt.Float}
)

Created table ‘orders’.

# Insert some data
orders.insert(
    [
        {'customer': 'Alice', 'amount': 150.00},
        {'customer': 'Bob', 'amount': 75.50},
    ]
)

Inserted 2 rows with 0 errors in 0.01 s (310.49 rows/s)
2 rows inserted.

# Add a UUID column to existing table
orders.add_computed_column(order_id=uuid7())

Added 2 column values with 0 errors in 0.02 s (98.14 rows/s)
2 rows updated.

# View orders with their UUID column
orders.collect()

Explanation

Two ways to add UUIDs:

Both use uuid7() which generates UUIDv7 (time-based) identifiers:

128-bit values
Formatted as 32 hex digits with hyphens: 018e65c5-35e5-7c5d-8f37-f1c5b9c8a7b2
Time-ordered for better database performance
Virtually guaranteed unique (collision probability is negligible)

Welcome to Pixeltable

Tools

Core Concepts

How-To

Problem

Solution

Setup

Create a table with a UUID primary key

Add a UUID column to an existing table

Explanation

See also

​Problem

​Solution

​Setup

​Create a table with a UUID primary key

​Add a UUID column to an existing table

​Explanation

​See also

Problem

Solution

Setup

Create a table with a UUID primary key

Add a UUID column to an existing table

Explanation

See also