can anyone explain me one to one and one to many and many to one and many to many relationship in sql with example plz

how the session states are stored in sql server ...where it will be configured before store it into sql server ?

can anyone tell me about sql transcation with example..what are the types are there ?

how will u send automatic email from sql ?

i have one student table
stu id sex coloums
1 male
2 female
3 female
4 male
5 female
...

sorry i have asked wrong question
when we go for trigger in sql 2000

when we for trigger in c# .net ..can anyone expalin me with simple example