Im working on a project where im trying to build a QTreeWidget that has multiple QTreeWidgetItems
and once i click on a particular item it connects to a database and shows a query result in a tableview model, until now every thing works fine.
the problem is that i want each item to output different resut depending on some criteria on the same table where this criteria is only changing the value of an attribute, and this value is the same of the item name. for example item named 122 and the table has atribute called no. when we click on item 122 the result of this query must be shown (select * from table where no=122)
any help :)
I am assuming you have a QTableView backed by a QSqlQueryModel or QSqlTableModel.
You can connect to the signal QTreeWidget::itemSelectionChanged() and then in the slot you get the current item with selectedItems()[0]. Then you create your query:
QSqlQuery query;
query.prepare("select * from table where no=:no");
query.bindValue(":no", number);
query.exec();
Finally you can use setQuery (const QSqlQuery & query) on the model. This should update your view.
I hope I understood correctly what you want to achieve.
Related
Initially, I used qsqlrelationtablemodel in my database project. And the values were entered into the database using the combobox inside the tableView. And it looked something like this:
enter image description here
And the code looked very simple:
model->setTable(sql_query);
model->setRelation(1, QSqlRelation("my_schema.aircrafts","id_aircraft","registration_number"));
model->setRelation(3, QSqlRelation("my_schema.airports","id_airport","name_airport"));
model->setRelation(4, QSqlRelation("my_schema.airports","id_airport","name_airport"));
ui->tableView->setModel(model);
ui->tableView->setItemDelegateForColumn(1, new QSqlRelationalDelegate(this));
ui->tableView->setItemDelegateForColumn(3, new QSqlRelationalDelegate(this));
ui->tableView->setItemDelegateForColumn(4, new QSqlRelationalDelegate(this));
But now I have redone the data entry on the forms and there are no problems with transferring information to qlineedit. There are difficulties with transferring data from foreign key's to an external combobox.
Now it looks like this (the value of the combobox does not change when you click on another row of the tableView):
enter image description here
Now I'm using this code, but I don't understand how to pass the value of the selected index in the tableView to the combobox.
QString query = QString("SELECT * FROM my_schema.route WHERE id_route = '%1'").arg(id);
QSqlQuery qw;
qw.exec(query);
while(qw.next())
{
ui->lineEdit->setText(qw.value(1).toString());
ui->lineEdit_2->setText(qw.value(2).toString());
ui->lineEdit_3->setText(qw.value(3).toString());
ui->comboBox_2->setModel(model);
ui->comboBox_2->setModelColumn(4);
}
I would like to see something like this result:
enter image description here
Please tell me in the most accessible form how to achieve this
You have model and tableview for fetching all columns for clicked row by using QAbstractItemView::clicked(const QModelIndex &index) signal for receive event. And implement the slot that loops all columns in selected row like this example snippet:
// create query with join for combobox model only containing desired values not foreign keys
// after that create QStringList and fill it with query result
// set stringlistmodel to combobox
ui->comboBox_2->setModel(stringlistmodel); // this is different from tableview's model
connect(ui->tableView, &QTableView::clicked, [this](const QModelIndex &index)
{
auto row{index.row()};
ui->lineEdit->setText(model.data(model.index(row, 0).toString());
//...
ui->comboBox_2->setCurrentIndex(model.data(model.index(row, 4).toInt());
//...
});
I have a table that contains duplicated records.
I used following code to put the data into a QTableView:
QSqlTableModel *dataModel = new QSqlTableModel();
dataModel->setTable("table_name");
dataModel->select();
now I wanna to query duplicated records. I use group by and having for do that in sql but I haven`t any idea to how do this in qt.
Finally I found the solution, I used "setFilter" method as bellow:
dataModel = new QSqlTableModel();
dataModel->setTable("CUSTOMER");
QString filter_txt = "id in (select id FROM CUSTOMER GROUP BY id HAVING count(*) >1)" ;
dataModel->setFilter(filter);
dataModel->select();
Here is my code:
QSqlRelationalTableModel *model = new QSqlRelationalTableModel(this, db1);
model->setTable("syllabi");
model->setRelation(3, QSqlRelation("activity_types", "activity_type_id", "activity_type_name"));
model->select();
ui->tableView->setModel(model);
ui->tableView->setItemDelegate(new QSqlRelationalDelegate(ui->tableView));
Values in combo boxes show correctly, but when I change the value and select another cell of the table, the cell shows the ID (foreign key) instead of its value.
Also, when I insert another value with this code
model->insertRow(model->rowCount());
model->setData(model->index(model->rowCount()-1, 0), teacherName);
there is a error:
QODBCResult::exec: Unable to execute statement: "[Microsoft][ODBC SQL Server Driver][SQL Server]Conversion failed when converting the nvarchar value 'default' to data type int."
The tables did't join correctly?
EDIT:
Okay, now when I change value in combo box it deletes the whole row. What might be the reason?
The tables: https://yadi.sk/i/ujL15zD_hupvz
I know it's pretty late, but anyway, here is the answer.
I have encountered the same problem but in pyqt. The problem was with EditStrategy.OnFieldChange That should behave like OnRowChange when inserting a new row but somehow keeps skipping lookups for relations during the edit of the new row. Changing the EditStrategy to OnRowChange solves the problem.
Here is the original answer I got for my problem.
What I would like to do is taking input from a sql database and put all these datas in a QListWidget, but I don't know how many of them there gonna be, I need also to know the id of which one was clicked when clicked.
Any ideas?
if str is the label from your sql query and n is the id then:
create your items with:
QListWidgetItem* i = new QListWidgetItem(str);
Set the id with:
i->setData(Qt::UserRole, n);
and add it to the widget:
myListWidget->addItem(i);
Then when its clicked you will get the signal
void QListWidget::itemActivated ( QListWidgetItem * item ) [signal]
connect this to a slot in your class and get the id back with
item->data(Qt::UserRole).toInt();
But this is also a good time to use QTableView and QSqlQueryModel.
After setting an INSERT or DELETE query on QSqlQueryModel, my QTableView becomes screwed up. For example I hid the ID column by calling view->hideColumn(ID); but after an INSERT or DELETE the ID column becomes visible.
How can I automatically reset my view to the previous settings in these cases?
I guess the problem is in QSqlQueryModel::setQuery you're eventually calling every time content gets reloaded and rows inserts\deletes. Looking at the setQuery implementation I would suggest: depending on the query your model can be reset including columns settings change which should trigger view columns update.
As Qt documentation suggests:
The QSqlQueryModel class provides a
read-only data model for SQL result
sets.
so I would use direct QSqlQuery calls for the data updates and then would reload the model with the same query. Or consider switching to QSQLTableModel, which is quite handy for single table content manipulation and supports inserts updates and deletes. See if an example below would work for you:
set up database, view and model:
QSqlTableModel *_model;
QTableView *_view;
...
QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
db.setDatabaseName(":memory:");
db.open() ;
QSqlQuery query;
query.prepare("CREATE TABLE IF NOT EXISTS person (id INTEGER UNIQUE PRIMARY KEY, name VARCHAR(30))");
query.exec();
query.prepare("INSERT INTO person (name) VALUES ('test1')");
query.exec();
query.prepare("INSERT INTO person (name) VALUES ('test2')");
query.exec();
_model = new QSqlTableModel(this, db);
_model->setTable("person");
_model->setEditStrategy(QSqlTableModel::OnManualSubmit);
_model->select();
_model->setHeaderData(1, Qt::Horizontal, tr("name"));
_model->setSort(1, Qt::AscendingOrder);
_view = new QTableView(this);
_view->setModel(_model);
_view->hideColumn(0);
add new row:
QSqlRecord record;
_model->insertRecord(-1, record);
delete selected row(s):
QModelIndexList selected = _view->selectionModel()->selectedIndexes();
for (int i = 0; i < selected.size(); ++i)
_model->removeRows(selected.at(i).row(), 1);
submit changes:
_model->submitAll();
hope this helps, regards