Hello Friends,
In this Video we will learn ON DELETE SET NULL keyword.
We will be create two tables called 1) dept(Department) and emp(Employee).
Here, dept table will serve as Parent table and emp table will serve as child table.
We will then add Foreign key Constraint at Child table.
we will then populate the data in Parent table and child table.
Our primary purpose is when i delete a particular record from my parent table (i.e. department table/dept) then referenced record column (dno) (i.e. a reference record value (dno) that is referred in child table should become null).
This is the concept of ON DELETE SET NULL i.e you delete a record from parent table and a concerned record value (dno in our case) from child table will null itself and rest of the columns value become as it is.
Thank you for Watching.
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Смотрите видео How to Implement ON DELETE SET NULL Constraint in Oracle 10g Database. онлайн без регистрации, длительностью часов минут секунд в хорошем качестве. Это видео добавил пользователь Hardik Parmar 20 Апрель 2019, не забудьте поделиться им ссылкой с друзьями и знакомыми, на нашем сайте его посмотрели 61 раз и оно понравилось 8 людям.