i am speaking about dbmansql !

do you know how to validate fields input when adding a record or modifying so the information in the tables cannot be repeatly stored with the same information in diferent id

i mean to prevent this

id | name | lastname | postion |

1 | a | a | a | ok

2 | a | a | a | not ok - (this row is not right or cannot be added)

3 | a | b | a | ok



if you see the 2 row is not right because cannot be the same person with equal name and lastname and position


can you help me with this so users cannot duplicate data!
KevinW ANDRE
webmaster@cyberbrickell.com