on delete mysql code example

Example 1: remove mysql

sudo apt-get remove --purge mysql* -y
sudo apt-get autoremove -y
sudo apt-get autoclean

Example 2: mysql delete row

DELETE FROM products WHERE product_id=1;

Example 3: MySQL DELETE

To delete data from a table, you use the MySQL DELETE statement. The following illustrates the syntax of the DELETE statement:

DELETE FROM table_name
WHERE condition;
In this statement:

First, specify the table from which you delete data.
Second, use a condition to specify which rows to delete in the WHERE clause. The DELETE statement will delete rows that match the condition,

Example 4: update foreign key value in mysql

SET foreign_key_checks = 0;
UPDATE languages SET id='xyz' WHERE id='abc';
UPDATE categories_languages SET language_id='xyz' WHERE language_id='abc';
SET foreign_key_checks = 1;

Example 5: mysql on delete set null

FOREIGN KEY (child_col1, child_col2, ... child_col_n)
    REFERENCES parent_table (parent_col1, parent_col2, ... parent_col_n)
    ON DELETE SET NULL
    [ ON UPDATE { NO ACTION | CASCADE | SET NULL | SET DEFAULT } ]