QSqlTableModel露

PyQt5.QtSql.QSqlTableModel

Description露

The QSqlTableModel class provides an editable data model for a single database table.

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(parentObject, database);
#     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鈥檚 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.

Enums露

EditStrategy

This enum type describes which strategy to choose when editing values in the database.

Note: To prevent inserting only partly initialized rows into the database, OnFieldChange will behave like OnRowChange for newly inserted rows.

See also

setEditStrategy().

Member	Value	Description
OnFieldChange	0	All changes to the model will be applied immediately to the database.
OnManualSubmit	2	All changes will be cached in the model until either submitAll() or revertAll() is called.
OnRowChange	1	Changes to a row will be applied when the user selects a different row.

Methods露

__init__(parent: QObject = None, db: QSqlDatabase = 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.

clear(): TODO

data(QModelIndex, role: int = Qt.ItemDataRole.DisplayRole) → Any: TODO

database() → QSqlDatabase: Returns the model鈥檚 database connection.

deleteRowFromTable(int) → bool

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

removeRow(), removeRows().

editStrategy() → EditStrategy: Returns the current edit strategy.

See also

setEditStrategy().

fieldIndex(str) → int: Returns the index of the field fieldName, or -1 if no corresponding field exists in the model.

filter() → str: Returns the currently set filter.

See also

setFilter(), select().

flags(QModelIndex) → ItemFlags: TODO

headerData(int, Orientation, role: int = Qt.ItemDataRole.DisplayRole) → Any: TODO

indexInQuery(QModelIndex) → QModelIndex

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

indexInQuery().

insertRecord(int, QSqlRecord) → bool

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.

insertRowIntoTable(QSqlRecord) → bool

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

lastError(), insertRow(), insertRows().

insertRows(int, int, parent: QModelIndex = QModelIndex()) → bool: TODO

isDirty() → bool: TODO

isDirty(QModelIndex) → bool

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.

orderByClause() → str: Returns an SQL ORDER BY clause based on the currently set sort order.

See also

setSort(), selectStatement().

primaryKey() → QSqlIndex: 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

setTable(), setPrimaryKey(), primaryIndex().

primaryValues(int) → QSqlRecord: TODO

record() → QSqlRecord: TODO

record(int) → QSqlRecord: TODO

removeColumns(int, int, parent: QModelIndex = QModelIndex()) → bool: TODO

removeRows(int, int, parent: QModelIndex = QModelIndex()) → bool: TODO

revert(): TODO

revertAll(): Reverts all pending changes.

See also

revert(), revertRow(), submitAll().

revertRow(int): Reverts all changes for the specified row.

See also

revert(), revertAll(), submit(), submitAll().

rowCount(parent: QModelIndex = QModelIndex()) → int: TODO

select() → bool

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.

Note: Calling will revert any unsubmitted changes and remove any inserted columns.

selectRow(int) → bool: TODO

selectStatement() → str: Returns the SQL SELECT statement used internally to populate the model. The statement includes the filter and the ORDER BY clause.

See also

filter(), orderByClause().

setData(QModelIndex, Any, role: int = Qt.ItemDataRole.EditRole) → bool: TODO

setEditStrategy(EditStrategy)

Sets the strategy for editing values in the database to strategy.

This will revert any pending changes.

See also

editStrategy(), revertAll().

setFilter(str)

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.

setPrimaryKey(QSqlIndex)

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

primaryKey(), primaryIndex().

setQuery(QSqlQuery): This function simply calls setQuery()(query). You should normally not call it on a QSqlTableModel. Instead, use setTable(), setSort(), setFilter(), etc., to set up the query.

See also

selectStatement().

setRecord(int, QSqlRecord) → bool

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

record(), editStrategy().

setSort(int, SortOrder): 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

sort(), select(), orderByClause().

setTable(str)

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鈥檚 data, call select().

Error information can be retrieved with lastError().

See also

select(), setFilter(), lastError().

sort(int, SortOrder): TODO

submit() → bool: TODO

submitAll() → bool

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鈥檛 be cleared from the cache when fails. This allows transactions to be rolled back and resubmitted without losing data.

See also

revertAll(), lastError().

tableName() → str: Returns the name of the currently selected table.

updateRowInTable(int, QSqlRecord) → bool

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 setGenerated() and tested with isGenerated().

See also

isGenerated(), setData().

Signals露

beforeDelete(int): TODO

beforeInsert(QSqlRecord): TODO

beforeUpdate(int, QSqlRecord): TODO

primeInsert(int, QSqlRecord): TODO