[feat]: Respond with Batch CQL statement executed instead of CQL statement executed when executing Batches

[millerjp]

Respond with Batch CQL statement executed instead of CQL statement executed.

Batch statments can be of three different types

• BEGIN BATCH - Logged batches ensure atomicity across multiple operations
• BEGIN UNLOGGED BATCH - unlogged batches are more performant for single-partition operation but are not atomic so usually avoid them but they need to be tested
• BEGIN COUNTER BATCH - counter batches are specifically for counter updates

Testing Batch Statments

Create a keyspace and tables:

-- Create keyspace
CREATE KEYSPACE IF NOT EXISTS batch_demo 
WITH replication = {'class': 'SimpleStrategy', 'replication_factor': 1};

USE batch_demo;

-- Product inventory table
CREATE TABLE products (
    product_id uuid,
    name text,
    price decimal,
    stock int,
    last_updated timestamp,
    PRIMARY KEY (product_id)
);

-- Customer orders table
CREATE TABLE orders (
    order_id uuid,
    customer_id uuid,
    product_id uuid,
    quantity int,
    order_status text,
    order_date timestamp,
    PRIMARY KEY (order_id)
);

-- Product views counter table
CREATE TABLE product_views (
    product_id uuid,
    view_count counter,
    PRIMARY KEY (product_id)
);

-- Shopping cart table (for LWT examples)
CREATE TABLE shopping_cart (
    cart_id uuid,
    product_id uuid,
    quantity int,
    version int,
    PRIMARY KEY (cart_id, product_id)
);

Logged Batch Example

BEGIN BATCH
    INSERT INTO products (product_id, name, price, stock, last_updated) 
    VALUES (uuid(), 'Laptop', 999.99, 10, toTimestamp(now()));
    
    INSERT INTO products (product_id, name, price, stock, last_updated) 
    VALUES (uuid(), 'Mouse', 29.99, 50, toTimestamp(now()));
    
    INSERT INTO products (product_id, name, price, stock, last_updated) 
    VALUES (uuid(), 'Keyboard', 59.99, 30, toTimestamp(now()));
APPLY BATCH;

Unlogged Batch Example

BEGIN UNLOGGED BATCH
    UPDATE products SET stock = stock - 1 WHERE product_id = 123e4567-e89b-12d3-a456-426614174000;
    
    INSERT INTO orders (order_id, customer_id, product_id, quantity, order_status, order_date)
    VALUES (uuid(), 123e4567-e89b-12d3-a456-426614174001, 
            123e4567-e89b-12d3-a456-426614174000, 1, 'PENDING', toTimestamp(now()));
APPLY BATCH;

Counter Batch Example

BEGIN COUNTER BATCH
    UPDATE product_views SET view_count = view_count + 1 
    WHERE product_id = 123e4567-e89b-12d3-a456-426614174000;
    
    UPDATE product_views SET view_count = view_count + 1 
    WHERE product_id = 123e4567-e89b-12d3-a456-426614174001;
APPLY BATCH;

LWT (Lightweight Transactions) Batch Examples

First, insert initial data:

INSERT INTO shopping_cart (cart_id, product_id, quantity, version) 
VALUES (123e4567-e89b-12d3-a456-426614174000, 
        123e4567-e89b-12d3-a456-426614174001, 1, 1);

Successful LWT batch:

BEGIN BATCH
    UPDATE shopping_cart 
    SET quantity = 2, version = 2 
    WHERE cart_id = 123e4567-e89b-12d3-a456-426614174000 
    AND product_id = 123e4567-e89b-12d3-a456-426614174001
    IF version = 1;
    
    INSERT INTO orders (order_id, customer_id, product_id, quantity, order_status, order_date)
    VALUES (uuid(), 123e4567-e89b-12d3-a456-426614174002, 
            123e4567-e89b-12d3-a456-426614174001, 2, 'PENDING', toTimestamp(now()));
APPLY BATCH;

Failing LWT batch (will fail because version is now 2):

BEGIN BATCH
    UPDATE shopping_cart 
    SET quantity = 3, version = 3 
    WHERE cart_id = 123e4567-e89b-12d3-a456-426614174000 
    AND product_id = 123e4567-e89b-12d3-a456-426614174001
    IF version = 1;
    
    INSERT INTO orders (order_id, customer_id, product_id, quantity, order_status, order_date)
    VALUES (uuid(), 123e4567-e89b-12d3-a456-426614174002, 
            123e4567-e89b-12d3-a456-426614174001, 3, 'PENDING', toTimestamp(now()));
APPLY BATCH;