SQL database transactions

Beginners of software development are not very familiar with stored procedures and transactions. Today, we will give you a simple example of a transaction, so that you can understand it first. Then we will explain the stored procedure to you.

Start transaction: Begin transaction

Commit transaction: commit transaction

Rollback transaction: rollback transaction

Example:

Begin transaction

Declare @ errorsum int -- defines local variables

Set @ errorsum = 0 -- initialize temporary variables

Update Bank set currentmoney = currentMoney-1000 where customername = 'zhang san'

Set @ errorsum = @ errorsum + @ error -- indicates whether an error exists.

Update Bank set currentmoney = currentmoney + 1000 where customername = 'Li si'

Set @ errorsum = @ errorsum + @ error -- indicates whether an error exists.

If @ errorsum <> 0 -- if an error occurs

Begin

Rollback transaction

End

Else

Begin

Commit transaction

End

Go

 

Start transaction: Begin transaction

Commit transaction: commit transaction

Rollback transaction: rollback transaction

Example:

Begin transaction

Declare @ errorsum int -- defines local variables

Set @ errorsum = 0 -- initialize temporary variables

Update Bank set currentmoney = currentMoney-1000 where customername = 'zhang san'

Set @ errorsum = @ errorsum + @ error -- indicates whether an error exists.

Update Bank set currentmoney = currentmoney + 1000 where customername = 'Li si'

Set @ errorsum = @ errorsum + @ error -- indicates whether an error exists.

If @ errorsum <> 0 -- if an error occurs

Begin

Rollback transaction

End

Else

Begin

Commit transaction

End

Go