QtSQL + Sqlite and support for .size() function?

问题

I'm wondering does QtSql + Sqlite support QSqlQuery::size() function?

回答1:

No, it does't. SQLite is one of the databases for which the size of the query is not directly available. BTW: A Google-query for "qt sqlite QSqlQuery size" had this StackOverflow question as first answer.

回答2:

No, it doesn't. However, you can use last() and at() together to get the result.

QSqlQuery q;
q.exec("select * from table");
q.last();
qDebug() << q.at() + 1;

回答3:

I also faced the same issue with SQLite and Qt.

As a solution I used

if (query.next())
{
}

to identify the query returns values or not.

But be careful it directs you to the first record. And if you need the no of records exactly, then this is not a solution.

来源：https://stackoverflow.com/questions/5373184/qtsql-sqlite-and-support-for-size-function