CODEWITHSUNDEEP
c++qtqt4
ivakon
ivakon

Reputation: 25

Columns number. QMYSQLResult::data: column out of range

Have database. Have query with unknown count of columns. Need to put all answer in QList 

database = QSqlDatabase::addDatabase("QMYSQL");
...
QString sql = "Select * from test";
QSqlQuery query = QSqlQuery(database);
query.exec(sql);

QList<QStringList> retList;

Use .isValid() on value. 

while (query.next()) {
int count = 0;
bool flagValues = true;
QStringList row;
while(flagValues)
{
    QVariant value = query.value(count);
    if(value.isValid() && !(count == memCount)   )
    {
        count++;
        row.append(value.toString());
    }
    else
    {
        flagValues = false;
    }
}
retList.append(row);

All is ok, but i have a messages (not error) like in every row. :

  QMYSQLResult::data: column 3 out of range

I do not want to use additional query (like information_schema) to know columns number.

Upvotes: 1

Views: 1987

Answers (1)

Kuba hasn&#39;t forgotten Monica
Kuba hasn&#39;t forgotten Monica

Reputation: 98485

Use query.record().count() to obtain the number of columns. Thus:

database = QSqlDatabase::addDatabase("QMYSQL");
...
QString sql = "Select * from test";
QSqlQuery query = QSqlQuery(database);
query.exec(sql);
const int memCount = query.record().count();
// query loop goes here

Upvotes: 1

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