100 Days of ClickHouse® – Day 6: Importing CSV Files into ClickHouse®

Source: Dev.to

CSV files are one of the most common formats for storing and exchanging data. Whether you’re working with logs, analytics data, application exports, or reports, there will likely come a time when you need to load CSV data into ClickHouse®. The good news is that ClickHouse® makes CSV ingestion straightforward and efficient. In this guide, you’ll learn how to create a table, prepare a CSV file, load CSV data into ClickHouse®, and verify that the data has been imported successfully. Why Use CSV Files with ClickHouse®? Common use cases include: Importing exported application data Sample CSV File id,name,department,salary Step 1: Create a Table in ClickHouse® CREATE TABLE employees Step 2: Load CSV Data into ClickHouse® Run the following command: clickhouse-client —query=” INSERT INTO employees FORMAT CSVWithNames” < employees.csv Step 3: Verify the Imported Data SELECT * FROM employees; ┌─id─┬─name───┬─department──┬─salary─┐ Using CSV Instead of CSVWithNames Example: 1,Alice,Engineering,75000 clickhouse-client —query=” Common Import Issues Always ensure that: Column order matches Header Row Problems Tips for Faster CSV Imports Import data in batches when possible Final Thoughts Whether you’re importing a small test dataset or a large historical archive, the process remains simple and efficient. With the steps covered in this guide, you should be able to confidently load CSV data into ClickHouse® and begin querying your data immediately. Original article - https://quantrail-data.com/load-csv-data-into-clickhouse-guide/