What would you say if I told you that none of the DML statements that you've executed in this chapter,
DELETEs, actually did anything to change data in the database? As much of a surprise as it is, it is actually true. The use of DML statements comes with a caveat: they must be used in conjunction with transaction control statements.
Transaction control is the act of manipulating the timing of events called transactions. In relational database theory, a transaction is a discrete unit of work within a database. Transactions allow groups of statements to be executed together, to allow for correct recovery in the event of failure. Transactions also represent data concurrency ...