VVContactRepository::remove

SourcePro : DB Interface Module User’s Guide : PART V The Tutorials : Deleting Rows from a Table : The Program : VVContactRepository::remove

The remove() member function of VVContactRepository takes a customer ID and removes the associated customer from the customer list.

VVContactRepository&

VVContactRepository::remove(unsigned long id) //1

{

RWDBDeleter aDeleter = table_.deleter(); //2

aDeleter.where(idColumn_ == id); //3

aDeleter.execute(); //4

return *this;

}

//1 This is the definition of the remove() member function of the VVContactRepository class. It accepts one argument, the ID of the customer to be terminated.

//2 Here a deleter object is produced from the table associated with this instance of VVContactRepository. Through this instance of RWDBDeleter, rows that match a certain criterion can be removed from the table. An RWDBDeleter object encapsulates the SQL DELETE statement.

//3 On this line, a condition is formed to limit the deletion to a specific row. This condition takes the form of an RWDBCriterion instance created when applying the operator== to an RWDBColumn instance and a number. For example, this would create a condition equivalent to customer.ID = 69, if customer number 69 were to be deleted.

//4 Once the deleter is given its condition, calling the execute() member function submits the DELETE statement to the database for execution.