Migration to change default value for a field and change all existing record's value to new default value only if it has old default value.

Question

I need to change the default value of a field from 0 to 3, but the catch is i have thousands of records already and want those records to change the value to 3 from 0 only if th

Answer 1

ALTER TABLE your_table MODIFY your_column tinyint(1) NOT NULL DEFAULT 3;
UPDATE your_table SET your_column=3 WHERE your_column=0;

1. assuming your column is tinyint(1), replace your self if not the same
2. NOT NULL is assuming you always force the column to be NOT NULl