Qt's odbc driver does not support LastInsertId with mysql, whats the workaround?

问题

Im using Qt 4.8.3 and the MySQL ODBC 3.51 Driver. The driver does not seem to support LastInsertId which I test like this:

db.driver()->hasFeature(QSqlDriver::LastInsertId)

I need it to find the auto increment id I just inserted

query.exec("INSERT INTO myTable (MyVal, Created) VALUES ('1', NOW())");
auto insertId = query.lastInsertId().toString();

What is the best workaround?

EDIT: there will be concurrent access to this table from multiple clients.

回答1:

According to MySQL documentation, you can call:

SELECT LAST_INSERT_ID();

after the insert query to get the latest id inserted for the current connection, even when using ODBC.

回答2:

You could do something like:

query.exec("SELECT id FROM myTable ORDER BY id DESC LIMIT 1");

to get the largest id in your table - this should be the one you just inserted.

If you are writing an application that can have multiple concurrent users you'll have to look into creating a lock on your table and then releasing the lock after you run this second query.

回答3:

Use OUTPUT INSERTED.[Field Name] as in code below. Read the returned ID with next() function.

bool RepeatsRecognizer::InsertEvent(RepEvent* event){
QSqlDatabase db = AppManager::DB_Output()->ThreadDatabase();
QSqlQuery query(db);
query.prepare("INSERT INTO RepEvents (ChannelID, StatsRangeUID, MinStartDateTime, MaxDuration, Fixed) OUTPUT INSERTED.ID"
              " VALUES (?, ?, ?, ?, ?)");
query.bindValue(0, event->ChannelID);
query.bindValue(1, event->StatsRangeUID.toString());
query.bindValue(2, event->MinStartDateTime);
query.bindValue(3, event->MaxDuration);
query.bindValue(4, false);


if (!query.exec())
    return false;

if (!query.next())
    return false;

event->ID = query.value(0).toLongLong();
qDebug() << __FUNCTION__ << "Event ID:" << event->ID;

}

来源：https://stackoverflow.com/questions/13709117/qts-odbc-driver-does-not-support-lastinsertid-with-mysql-whats-the-workaround

标签

mysql

odbc

last-insert-id