on delete cascade in mysql code example
Example 1: mysql drop table cascade
SET FOREIGN_KEY_CHECKS = 0;
drop table if exists <your_1st_table>;
drop table if exists <your_2nd_table>;
SET FOREIGN_KEY_CHECKS = 1;
Example 2: on delete cascade
CREATE TABLE child_table
(
column1 datatype [ NULL | NOT NULL ],
column2 datatype [ NULL | NOT NULL ],
...
CONSTRAINT fk_name
FOREIGN KEY (child_col1, child_col2, ... child_col_n)
REFERENCES parent_table (parent_col1, parent_col2, ... parent_col_n)
ON DELETE CASCADE
[ ON UPDATE { NO ACTION | CASCADE | SET NULL | SET DEFAULT } ]
);
Example 3: mysql on delete
[CONSTRAINT [symbol]] FOREIGN KEY
[index_name] (col_name, ...)
REFERENCES tbl_name (col_name,...)
[ON DELETE reference_option]
[ON UPDATE reference_option]
reference_option:
RESTRICT | CASCADE | SET NULL | NO ACTION | SET DEFAULT