Copy table data from one databse to another databse table daily

[sunilpaladugu]

Hi all

I am describing my problem below can any body plz look into this

I have two databases
DB1:datain1
DB2:datain2
having the below structure

database, table, fields
datain1 , student , id,name
datain2 , student , id,name

the two databases having same structure

My query is

i want copy all data from datain1 to datain2 on daily process through php script(script will be executed manually on daily)

i don't want any duplicate data in datain2

give me some script to do this

kindly help me to solve this its so urgent