ClickHouse Data Update Guide

There are multiple ways to update data in ClickHouse, depending on your specific needs and amount of data.

1. You can use an INSERT query to insert new data into a table, which is the most common method of updating data. For example:

INSERT INTO table_name (column1, column2) VALUES (value1, value2);

1. You can update existing data in a table by using an UPDATE query. For example:

UPDATE table_name SET column1 = value1 WHERE column2 = value2;

1. By using the ALTER TABLE command, you can modify the structure of a table, such as adding new columns or changing the data type of columns. This method is suitable for situations where changes to the table structure are needed.
2. If you are storing data using the MergeTree engine, you can update it using a special UPDATE query syntax. For example:

ALTER TABLE table_name UPDATE column1 = value1 WHERE condition;

Please note that ClickHouse is a distributed database primarily focused on insertion, so the efficiency of updating data may not be as high as other database systems. When considering updating data, please choose the most suitable method based on actual needs and data volume.