如何使A表某【信息】删除B表【相关信息】也强制删除（A的主键是B的外键）
我有两个表，代码如下，怎么样可以使booking表中某条信息被删除后，information表中相关信息也强制删除，不要重新建表，在cmd里面怎么写SQL语句？

SQL code

create table booking( o_id bigint(20) not null primary key, o_user int(10) not null, o_time varchar(50) not null, o_state varchar(10) not null, o_delivery varchar(50), o_ems varchar(20), o_number int(20), o_total float(6,2) not null, foreign key(o_user) references user(u_id) )engine=InnoDB charset=utf8;create table information( i_id int(10) not null auto_increment primary key, i_orderid bigint(20) not null, i_name varchar(50) not null, i_number int(10) not null, i_price float(6,2) not null, foreign key(i_orderid) references booking(o_id)      //外键 )engine=InnoDB charset=utf8;

[解决办法]
create table booking(
o_id bigint(20) not null primary key,
o_user int(10) not null,
o_time varchar(50) not null,
o_state varchar(10) not null,
o_delivery varchar(50),
o_ems varchar(20),
o_number int(20),
o_total float(6,2) not null
)engine=InnoDB charset=utf8;


create table information(
i_id int(10) not null auto_increment primary key,
i_orderid bigint(20) not null,
i_name varchar(50) not null,
i_number int(10) not null,
i_price float(6,2) not null,
CONSTRAINT `i_orderid` FOREIGN KEY (`i_id`) REFERENCES `booking` (`o_id`) ON DELETE CASCADE ON UPDATE CASCADE
)engine=InnoDB charset=utf8;


[解决办法]
如果不想重建 可以这样
1.找出原来建立好的外键约束

SQL code

SELECTke.referenced_table_name parent,ke.table_name child,ke.REFERENCED_COLUMN_NAME parent_column,   ke.column_name child_column,ke.constraint_nameFROMinformation_schema.KEY_COLUMN_USAGE keWHEREke.referenced_table_name IS NOT NULLand ke.referenced_table_name = 'booking'and ke.REFERENCED_COLUMN_NAME = 'o_id'and ke.REFERENCED_TABLE_SCHEMA = '你的数据库名字'ORDER BY ke.referenced_table_name;