QSqlTableModel Class▲
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Header: QSqlTableModel
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CMake:
find_package(Qt6 REQUIRED COMPONENTS Sql)
target_link_libraries(mytarget PRIVATE Qt6::Sql)
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qmake: QT += sql
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Inherits: QSqlQueryModel
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Inherited By: QSqlRelationalTableModel
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Group: QSqlTableModel is part of Database Classes
Detailed Description▲
QSqlTableModel is a high-level interface for reading and writing database records from a single table. It is built on top of the lower-level QSqlQuery and can be used to provide data to view classes such as QTableView. For example:
QSqlTableModel *model = new QSqlTableModel;
model->setTable("employee");
model->setEditStrategy(QSqlTableModel::OnManualSubmit);
model->select();
model->setHeaderData(0, Qt::Horizontal, tr("Name"));
model->setHeaderData(1, Qt::Horizontal, tr("Salary"));
QTableView *view = new QTableView;
view->setModel(model);
view->hideColumn(0); // don't show the ID
view->show();We set the SQL table's name and the edit strategy, then we set up the labels displayed in the view header. The edit strategy dictates when the changes done by the user in the view are actually applied to the database. The possible values are OnFieldChange, OnRowChange, and OnManualSubmit.
QSqlTableModel can also be used to access a database programmatically, without binding it to a view:
QSqlTableModel model;
model.setTable("employee");
model.select();
int salary = model.record(4).value("salary").toInt();The code snippet above extracts the salary field from record 4 in the result set of the query SELECT * from employee.
It is possible to set filters using setFilter(), or modify the sort order using setSort(). At the end, you must call select() to populate the model with data.
The tablemodel example illustrates how to use QSqlTableModel as the data source for a QTableView.
QSqlTableModel provides no direct support for foreign keys. Use the QSqlRelationalTableModel and QSqlRelationalDelegate if you want to resolve foreign keys.
See Also▲
Member Type Documentation▲
enum QSqlTableModel::EditStrategy▲
This enum type describes which strategy to choose when editing values in the database.
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Constant |
Value |
Description |
|---|---|---|
|
QSqlTableModel::OnFieldChange |
0 |
All changes to the model will be applied immediately to the database. |
|
QSqlTableModel::OnRowChange |
1 |
Changes to a row will be applied when the user selects a different row. |
|
QSqlTableModel::OnManualSubmit |
2 |
All changes will be cached in the model until either submitAll() or revertAll() is called. |
Note: To prevent inserting only partly initialized rows into the database, OnFieldChange will behave like OnRowChange for newly inserted rows.
See Also▲
See also setEditStrategy()
Member Function Documentation▲
[explicit] QSqlTableModel::QSqlTableModel(QObject *parent = nullptr, const QSqlDatabase &db = QSqlDatabase())▲
Creates an empty QSqlTableModel and sets the parent to parent and the database connection to db. If db is not valid, the default database connection will be used.
The default edit strategy is OnRowChange.
[virtual] QSqlTableModel::~QSqlTableModel()▲
Destroys the object and frees any allocated resources.
void QSqlTableModel::beforeDelete(int row)▲
This signal is emitted by deleteRowFromTable() before the row is deleted from the currently active database table.
void QSqlTableModel::beforeInsert(QSqlRecord &record)▲
This signal is emitted by insertRowIntoTable() before a new row is inserted into the currently active database table. The values that are about to be inserted are stored in record and can be modified before they will be inserted.
void QSqlTableModel::beforeUpdate(int row, QSqlRecord &record)▲
This signal is emitted by updateRowInTable() before the row is updated in the currently active database table with the values from record.
Note that only values that are marked as generated will be updated. The generated flag can be set with QSqlRecord::setGenerated() and checked with QSqlRecord::isGenerated().
See Also▲
See also QSqlRecord::isGenerated()
[override virtual] void QSqlTableModel::clear()▲
Reimplements: QSqlQueryModel::clear().
[override virtual] bool QSqlTableModel::clearItemData(const QModelIndex &index)▲
Reimplements: QAbstractItemModel::clearItemData(const QModelIndex &index).
[override virtual] QVariant QSqlTableModel::data(const QModelIndex &index, int role = Qt::DisplayRole) const▲
Reimplements: QSqlQueryModel::data(const QModelIndex &item, int role) const.
See Also▲
See also setData()
QSqlDatabase QSqlTableModel::database() const▲
Returns the model's database connection.
[virtual protected] bool QSqlTableModel::deleteRowFromTable(int row)▲
Deletes the given row from the currently active database table.
This is a low-level method that operates directly on the database and should not be called directly. Use removeRow() or removeRows() to delete values. The model will decide depending on its edit strategy when to modify the database.
Returns true if the row was deleted; otherwise returns false.
See Also▲
See also removeRow(), removeRows()
QSqlTableModel::EditStrategy QSqlTableModel::editStrategy() const▲
int QSqlTableModel::fieldIndex(const QString &fieldName) const▲
Returns the index of the field fieldName, or -1 if no corresponding field exists in the model.
QString QSqlTableModel::filter() const▲
[override virtual] Qt::ItemFlags QSqlTableModel::flags(const QModelIndex &index) const▲
Reimplements: QAbstractTableModel::flags(const QModelIndex &index) const.
[override virtual] QVariant QSqlTableModel::headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const▲
[override virtual protected] QModelIndex QSqlTableModel::indexInQuery(const QModelIndex &item) const▲
Reimplements: QSqlQueryModel::indexInQuery(const QModelIndex &item) const.
Returns the index of the value in the database result set for the given item in the model.
The return value is identical to item if no columns or rows have been inserted, removed, or moved around.
Returns an invalid model index if item is out of bounds or if item does not point to a value in the result set.
See Also▲
See also QSqlQueryModel::indexInQuery()
bool QSqlTableModel::insertRecord(int row, const QSqlRecord &record)▲
Inserts the record at position row. If row is negative, the record will be appended to the end. Calls insertRows() and setRecord() internally.
Returns true if the record could be inserted, otherwise false.
Changes are submitted immediately for OnFieldChange and OnRowChange. Failure does not leave a new row in the model.
See Also▲
See also insertRows(), removeRows(), setRecord()
[virtual protected] bool QSqlTableModel::insertRowIntoTable(const QSqlRecord &values)▲
Inserts the values values into the currently active database table.
This is a low-level method that operates directly on the database and should not be called directly. Use insertRow() and setData() to insert values. The model will decide depending on its edit strategy when to modify the database.
Returns true if the values could be inserted, otherwise false. Error information can be retrieved with lastError().
See Also▲
See also lastError(), insertRow(), insertRows()
[override virtual] bool QSqlTableModel::insertRows(int row, int count, const QModelIndex &parent = QModelIndex())▲
Reimplements: QAbstractItemModel::insertRows(int row, int count, const QModelIndex &parent).
Inserts count empty rows at position row. Note that parent must be invalid, since this model does not support parent-child relations.
For edit strategies OnFieldChange and OnRowChange, only one row may be inserted at a time and the model may not contain other cached changes.
The primeInsert() signal will be emitted for each new row. Connect to it if you want to initialize the new row with default values.
Does not submit rows, regardless of edit strategy.
Returns false if the parameters are out of bounds or the row cannot be inserted; otherwise returns true.
See Also▲
See also primeInsert(), insertRecord()
bool QSqlTableModel::isDirty(const QModelIndex &index) const▲
Returns true if the value at the index index is dirty, otherwise false. Dirty values are values that were modified in the model but not yet written into the database.
If index is invalid or points to a non-existing row, false is returned.
[since 5.0] bool QSqlTableModel::isDirty() const▲
This is an overloaded function.
Returns true if the model contains modified values that have not been committed to the database, otherwise false.
This function was introduced in Qt 5.0.
[virtual protected] QString QSqlTableModel::orderByClause() const▲
Returns an SQL ORDER BY clause based on the currently set sort order.
See Also▲
See also setSort(), selectStatement()
QSqlIndex QSqlTableModel::primaryKey() const▲
Returns the primary key for the current table, or an empty QSqlIndex if the table is not set or has no primary key.
See Also▲
See also setTable(), setPrimaryKey(), QSqlDatabase::primaryIndex()
[protected, since 5.1] QSqlRecord QSqlTableModel::primaryValues(int row) const▲
Returns a record containing the fields represented in the primary key set to the values at row. If no primary key is defined, the returned record will contain all fields.
This function was introduced in Qt 5.1.
See Also▲
See also primaryKey()
void QSqlTableModel::primeInsert(int row, QSqlRecord &record)▲
This signal is emitted by insertRows(), when an insertion is initiated in the given row of the currently active database table. The record parameter can be written to (since it is a reference), for example to populate some fields with default values and set the generated flags of the fields. Do not try to edit the record via other means such as setData() or setRecord() while handling this signal.
QSqlRecord QSqlTableModel::record() const▲
This is an overloaded function.
It returns an empty record, having only the field names. This function can be used to retrieve the field names of a record.
See Also▲
See also setRecord(), QSqlRecord::isEmpty()
[since 5.0] QSqlRecord QSqlTableModel::record(int row) const▲
Returns the record at row in the model.
If row is the index of a valid row, the record will be populated with values from that row.
If the model is not initialized, an empty record will be returned.
This function was introduced in Qt 5.0.
See Also▲
See also QSqlRecord::isEmpty()
[override virtual] bool QSqlTableModel::removeColumns(int column, int count, const QModelIndex &parent = QModelIndex())▲
Reimplements: QSqlQueryModel::removeColumns(int column, int count, const QModelIndex &parent).
Removes count columns from the parent model, starting at index column.
Returns if the columns were successfully removed; otherwise returns false.
See Also▲
See also removeRows()
[override virtual] bool QSqlTableModel::removeRows(int row, int count, const QModelIndex &parent = QModelIndex())▲
Reimplements: QAbstractItemModel::removeRows(int row, int count, const QModelIndex &parent).
Removes count rows starting at row. Since this model does not support hierarchical structures, parent must be an invalid model index.
When the edit strategy is OnManualSubmit, deletion of rows from the database is delayed until submitAll() is called.
For OnFieldChange and OnRowChange, only one row may be deleted at a time and only if no other row has a cached change. Deletions are submitted immediately to the database. The model retains a blank row for successfully deleted row until refreshed with select().
After failed deletion, the operation is not reverted in the model. The application may resubmit or revert.
Inserted but not yet successfully submitted rows in the range to be removed are immediately removed from the model.
Before a row is deleted from the database, the beforeDelete() signal is emitted.
If row < 0 or row + count > rowCount(), no action is taken and false is returned. Returns true if all rows could be removed; otherwise returns false. Detailed database error information can be retrieved using lastError().
See Also▲
See also removeColumns(), insertRows()
[override virtual] void QSqlTableModel::revert()▲
Reimplements: QAbstractItemModel::revert().
This reimplemented slot is called by the item delegates when the user canceled editing the current row.
Reverts the changes if the model's strategy is set to OnRowChange or OnFieldChange. Does nothing for the OnManualSubmit strategy.
Use revertAll() to revert all pending changes for the OnManualSubmit strategy or revertRow() to revert a specific row.
See Also▲
void QSqlTableModel::revertAll()▲
[virtual] void QSqlTableModel::revertRow(int row)▲
Reverts all changes for the specified row.
See Also▲
[override virtual] int QSqlTableModel::rowCount(const QModelIndex &parent = QModelIndex()) const▲
Reimplements: QSqlQueryModel::rowCount(const QModelIndex &parent) const.
[virtual] bool QSqlTableModel::select()▲
Populates the model with data from the table that was set via setTable(), using the specified filter and sort condition, and returns true if successful; otherwise returns false.
Calling select() will revert any unsubmitted changes and remove any inserted columns.
See Also▲
See also setTable(), setFilter(), selectStatement()
[virtual, since 5.0] bool QSqlTableModel::selectRow(int row)▲
Refreshes row in the model with values from the database table row matching on primary key values. Without a primary key, all column values must match. If no matching row is found, the model will show an empty row.
Returns true if successful; otherwise returns false.
This function was introduced in Qt 5.0.
See Also▲
See also select()
[virtual protected] QString QSqlTableModel::selectStatement() const▲
Returns the SQL SELECT statement used internally to populate the model. The statement includes the filter and the ORDER BY clause.
See Also▲
See also filter(), orderByClause()
[override virtual] bool QSqlTableModel::setData(const QModelIndex &index, const QVariant &value, int role = Qt::EditRole)▲
Reimplements: QAbstractItemModel::setData(const QModelIndex &index, const QVariant &value, int role).
Sets the data for the item index for the role role to value.
For edit strategy OnFieldChange, an index may receive a change only if no other index has a cached change. Changes are submitted immediately. However, rows that have not yet been inserted in the database may be freely changed and are not submitted automatically. Submitted changes are not reverted upon failure.
For OnRowChange, an index may receive a change only if no other row has a cached change. Changes are not submitted automatically.
Returns true if value is equal to the current value. However, the value will not be submitted to the database.
Returns true if the value could be set or false on error, for example if index is out of bounds.
Returns false if the role is not Qt::EditRole. To set data for roles other than EditRole, either use a custom proxy model or subclass QSqlTableModel.
See Also▲
See also editStrategy(), data(), submit(), submitAll(), revertRow()
[virtual] void QSqlTableModel::setEditStrategy(QSqlTableModel::EditStrategy strategy)▲
Sets the strategy for editing values in the database to strategy.
This will revert any pending changes.
See Also▲
See also editStrategy(), revertAll()
[virtual] void QSqlTableModel::setFilter(const QString &filter)▲
Sets the current filter to filter.
The filter is a SQL WHERE clause without the keyword WHERE (for example, name='Josephine').
If the model is already populated with data from a database, the model re-selects it with the new filter. Otherwise, the filter will be applied the next time select() is called.
See Also▲
See also filter(), select(), selectStatement(), orderByClause()
[protected] void QSqlTableModel::setPrimaryKey(const QSqlIndex &key)▲
Protected method that allows subclasses to set the primary key to key.
Normally, the primary index is set automatically whenever you call setTable().
See Also▲
See also primaryKey(), QSqlDatabase::primaryIndex()
bool QSqlTableModel::setRecord(int row, const QSqlRecord &values)▲
Applies values to the row in the model. The source and target fields are mapped by field name, not by position in the record.
Note that the generated flags in values are preserved to determine whether the corresponding fields are used when changes are submitted to the database. By default, it is set to true for all fields in a QSqlRecord. You must set the flag to false using setGenerated(false) for any value in values, to save changes back to the database.
For edit strategies OnFieldChange and OnRowChange, a row may receive a change only if no other row has a cached change. Changes are submitted immediately. Submitted changes are not reverted upon failure.
Returns true if all the values could be set; otherwise returns false.
See Also▲
See also record(), editStrategy()
[virtual] void QSqlTableModel::setSort(int column, Qt::SortOrder order)▲
Sets the sort order for column to order. This does not affect the current data, to refresh the data using the new sort order, call select().
See Also▲
See also sort(), select(), orderByClause()
[virtual] void QSqlTableModel::setTable(const QString &tableName)▲
Sets the database table on which the model operates to tableName. Does not select data from the table, but fetches its field information.
To populate the model with the table's data, call select().
Error information can be retrieved with lastError().
See Also▲
[override virtual] void QSqlTableModel::sort(int column, Qt::SortOrder order)▲
Reimplements: QAbstractItemModel::sort(int column, Qt::SortOrder order).
Sorts the data by column with the sort order order. This will immediately select data, use setSort() to set a sort order without populating the model with data.
See Also▲
See also setSort(), select(), orderByClause()
[override virtual] bool QSqlTableModel::submit()▲
Reimplements: QAbstractItemModel::submit().
This reimplemented slot is called by the item delegates when the user stopped editing the current row.
Submits the currently edited row if the model's strategy is set to OnRowChange or OnFieldChange. Does nothing for the OnManualSubmit strategy.
Use submitAll() to submit all pending changes for the OnManualSubmit strategy.
Returns true on success; otherwise returns false. Use lastError() to query detailed error information.
Does not automatically repopulate the model. Submitted rows are refreshed from the database on success.
See Also▲
bool QSqlTableModel::submitAll()▲
Submits all pending changes and returns true on success. Returns false on error, detailed error information can be obtained with lastError().
In OnManualSubmit, on success the model will be repopulated. Any views presenting it will lose their selections.
Note: In OnManualSubmit mode, already submitted changes won't be cleared from the cache when submitAll() fails. This allows transactions to be rolled back and resubmitted without losing data.
See Also▲
QString QSqlTableModel::tableName() const▲
Returns the name of the currently selected table.
[virtual protected] bool QSqlTableModel::updateRowInTable(int row, const QSqlRecord &values)▲
Updates the given row in the currently active database table with the specified values. Returns true if successful; otherwise returns false.
This is a low-level method that operates directly on the database and should not be called directly. Use setData() to update values. The model will decide depending on its edit strategy when to modify the database.
Note that only values that have the generated-flag set are updated. The generated-flag can be set with QSqlRecord::setGenerated() and tested with QSqlRecord::isGenerated().
See Also▲
See also QSqlRecord::isGenerated(), setData()