myConnection
QSqlDatabasePrivate::removeDatabase: connection ‘myConnection’ is still in use, all queries will cease to work
1. 解决QSqlDatabasePrivate::removeDatabase: connection ‘myConnection’ is still in use, all queries will cease to work的问题该问题主要是因为没有关闭之前的数据库连接，然后又需要创建新的数据 ......