Why data loading is the warehouse foundation in Snowflake - See It in Action

Why data loading is the warehouse foundation

📖 Scenario: You are working as a data engineer for a retail company. Your team uses Snowflake as the data warehouse to store and analyze sales data. Before analysts can run reports, you need to load raw sales data into the warehouse correctly.

🎯 Goal: Build a simple Snowflake setup that shows how to load data into a table. This will help you understand why loading data properly is the foundation of a data warehouse.

📋 What You'll Learn

Create a table called sales_data with columns order_id, product, and amount

Create a stage called sales_stage to hold the data files

Load data from a CSV file in sales_stage into sales_data

Verify the data loading step is complete

💡 Why This Matters

🌍 Real World

Loading data into a data warehouse is the first step before any analysis or reporting can happen. It ensures data is organized and ready for use.

💼 Career

Data engineers and cloud architects must know how to load data efficiently and correctly to build reliable data warehouses.

1

Create the sales_data table

Write a Snowflake SQL command to create a table called sales_data with three columns: order_id as INTEGER, product as VARCHAR(50), and amount as NUMBER(10,2).

Snowflake

-- Your code here

Need a hint?

Use CREATE TABLE followed by the table name and column definitions inside parentheses.

2

Create the sales_stage stage

Write a Snowflake SQL command to create an internal stage called sales_stage where data files will be stored before loading.

Snowflake

CREATE TABLE sales_data (
  order_id INTEGER,
  product VARCHAR(50),
  amount NUMBER(10,2)
);
-- Your code here

Need a hint?

Use CREATE STAGE followed by the stage name.

3

Load data from sales_stage into sales_data

Write a Snowflake SQL command to copy data from a CSV file in the sales_stage stage into the sales_data table. Assume the CSV file is named sales.csv and has headers.

Snowflake

CREATE TABLE sales_data (
  order_id INTEGER,
  product VARCHAR(50),
  amount NUMBER(10,2)
);

CREATE STAGE sales_stage;
-- Your code here

Need a hint?

Use COPY INTO with the table name, stage path, and file format options to load CSV data.

4

Verify data loading is complete

Write a Snowflake SQL command to select all rows from the sales_data table to verify the data was loaded.

Snowflake

CREATE TABLE sales_data (
  order_id INTEGER,
  product VARCHAR(50),
  amount NUMBER(10,2)
);

CREATE STAGE sales_stage;

COPY INTO sales_data
FROM @sales_stage/sales.csv
FILE_FORMAT = (TYPE = 'CSV' FIELD_OPTIONALLY_ENCLOSED_BY='"' SKIP_HEADER=1);
-- Your code here

Need a hint?

Use SELECT * FROM sales_data; to see all the loaded rows.