Mysql repeat column value till with condition

All we need is an easy explanation of the problem, so here it is.

I’ve a table :

Mysql repeat column value till with condition

I want the value of the driver to be repeated in the incoming rows in column driver until io_1 become 0, it set it to 0

How to solve :

I know you bored from this bug, So we are here to help you! Take a deep breath and look at the explanation of your problem. We have many solutions to this problem, But we recommend you to use the first method because it is tested & true method that will 100% work for you.

Method 1

Update existing data:

UPDATE test
CROSS JOIN ( SELECT MAX(driver) driver
             FROM test ) data
SET test.driver = data.driver
WHERE test.io_1;

Autofill during further insertions:

CREATE TRIGGER trigger_name
BEFORE INSERT
ON test
FOR EACH ROW
SET NEW.driver = CASE WHEN io_1 = 0
                      THEN 0
                      ELSE ( SELECT MAX(driver)
                             FROM test );

https://dbfiddle.uk/?rdbms=mysql_8.0&fiddle=d19f25bf3b40732b65d3eeb3f8fbe6bc

Note: Use and implement method 1 because this method fully tested our system.
Thank you 🙂

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