Dear All !
I have a table member_email. i have 4 columns in it.
I want to create constraint who check following conditions,
1-Email can be null if Cellnumber is given , and Cellnumber can be null if email is given.
2-both email and cell number can not be null in one record.
3-If cellnumber is available then carrier should not be null. Carrier will be null if email is given and cellnumber is not available.