Qt Qt - Dealing with Databases Remove Database connection correctly
Example
If we want to remove some database connection from the list of database connections.
we need to use QSqlDatabase::removeDatabase(),however it's a static function and the way it work is a little wired.
// WRONG WAY
QSqlDatabase db = QSqlDatabase::database("sales");
QSqlQuery query("SELECT NAME, DOB FROM EMPLOYEES", db);
QSqlDatabase::removeDatabase("sales"); // will output a warning
// "db" is now a dangling invalid database connection,
// "query" contains an invalid result set
The correct way that Qt Document suggest us is below.
{
QSqlDatabase db = QSqlDatabase::database("sales");
QSqlQuery query("SELECT NAME, DOB FROM EMPLOYEES", db);
}
// Both "db" and "query" are destroyed because they are out of scope
QSqlDatabase::removeDatabase("sales"); // correct
