mysql - alter table statment to insert duplicate into another table -

i have table in there column name sp varchar(10) not null. want column unique created unique index on column . table schema follows :

create table if not exists `tblspmaster` (   `csn` bigint(20) not null auto_increment,   `sp` varchar(10) not null,   `fileimporteddate` date not null,   `amzfilename` varchar(50) not null,   `casperbatch` varchar(50) not null,   `batchprocesseddate` date not null,   `expirydate` date not null,   `region` varchar(50) not null,   `fccity` varchar(50) not null,   `vendorid` int(11) not null,   `locationid` int(11) not null,   primary key (`csn`),   unique key `sp` (`sp`) ) engine=innodb  default charset=latin1 auto_increment=10000000000 ; 

now want if tries insert duplicate record record should inserted secondary table name tblduplicate.

i have gone through question mysql - ignore insert error: duplicate entry not sure instead of

insert tbl values (1,200) on duplicate key update value=200; 

can insert duplicate row table ?

what changes needed done in main table scheme or index column ?

**note : data inserted importing excel or csv files , excel files contains 500k 800 k records there 1 single column **

i believe want use trigger this. here mysql reference chapter on triggers.

use before insert trigger. in trigger, check if row duplicate (maybe count(*) key column value = value inserted). if row duplicate, perform insert secondary table.