QSqlTableModel Class

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

Header: #include <QSqlTableModel>
CMake: find_package(Qt6 COMPONENTS Sql REQUIRED)
target_link_libraries(mytarget PRIVATE Qt6::Sql)
qmake: QT += sql
继承: QSqlQueryModel
继承者:

QSqlRelationalTableModel

公共类型

enum EditStrategy { OnFieldChange, OnRowChange, OnManualSubmit }

公共函数

QSqlTableModel (QObject * parent = nullptr, const QSqlDatabase & db = QSqlDatabase())
virtual ~QSqlTableModel ()
QSqlDatabase database () const
QSqlTableModel::EditStrategy editStrategy () const
int fieldIndex (const QString & fieldName ) const
QString filter () const
bool insertRecord (int row , const QSqlRecord & record )
bool isDirty (const QModelIndex & index ) const
bool isDirty () const
QSqlIndex primaryKey () const
QSqlRecord record () const
QSqlRecord record (int row ) const
virtual void revertRow (int row )
virtual void setEditStrategy (QSqlTableModel::EditStrategy strategy )
virtual void setFilter (const QString & filter )
bool setRecord (int row , const QSqlRecord & values )
virtual void setSort (int column , Qt::SortOrder order )
virtual void setTable (const QString & tableName )
QString tableName () const

重实现公共函数

virtual void clear () override
virtual bool clearItemData (const QModelIndex & index ) override
virtual QVariant data (const QModelIndex & index , int role = Qt::DisplayRole) const override
virtual Qt::ItemFlags flags (const QModelIndex & index ) const override
virtual QVariant headerData (int section , Qt::Orientation orientation , int role = Qt::DisplayRole) const override
virtual bool insertRows (int row , int count , const QModelIndex & parent = QModelIndex()) override
virtual bool removeColumns (int column , int count , const QModelIndex & parent = QModelIndex()) override
virtual bool removeRows (int row , int count , const QModelIndex & parent = QModelIndex()) override
virtual int rowCount (const QModelIndex & parent = QModelIndex()) const override
virtual bool setData (const QModelIndex & index , const QVariant & value , int role = Qt::EditRole) override
virtual void sort (int column , Qt::SortOrder order ) override

公共槽

virtual void revert () override
void revertAll ()
virtual bool select ()
virtual bool selectRow (int row )
virtual bool submit () override
bool submitAll ()

信号

void beforeDelete (int row )
void beforeInsert (QSqlRecord & record )
void beforeUpdate (int row , QSqlRecord & record )
void primeInsert (int row , QSqlRecord & record )

保护函数

virtual bool deleteRowFromTable (int row )
virtual bool insertRowIntoTable (const QSqlRecord & values )
virtual QString orderByClause () const
QSqlRecord primaryValues (int row ) const
virtual QString selectStatement () const
void setPrimaryKey (const QSqlIndex & key )
void setQuery (const QSqlQuery & query )
virtual bool updateRowInTable (int row , const QSqlRecord & values )

重实现保护函数

virtual QModelIndex indexInQuery (const QModelIndex & item ) const override

详细描述

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 。例如:

    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 ,和 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.

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.

另请参阅 QSqlRelationalTableModel , QSqlQuery , 模型/视图编程 , 表格模型范例 ,和 Cached Table Example .

成员类型文档编制

enum QSqlTableModel:: EditStrategy

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

常量 描述
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 () 或 revertAll () 被调用。

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

另请参阅 setEditStrategy ().

成员函数文档编制

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 。若 db is not valid, the default database connection will be used.

The default edit strategy is OnRowChange .

[signal] void QSqlTableModel:: beforeDelete ( int row )

此信号被发射由 deleteRowFromTable () before the row is deleted from the currently active database table.

[signal] void QSqlTableModel:: beforeInsert ( QSqlRecord & record )

此信号被发射由 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.

[signal] void QSqlTableModel:: beforeUpdate ( int row , QSqlRecord & record )

此信号被发射由 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 ().

另请参阅 QSqlRecord::isGenerated ().

[signal] void QSqlTableModel:: primeInsert ( int row , QSqlRecord & record )

此信号被发射由 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 () 或 setRecord () while handling this signal.

[override virtual slot] void QSqlTableModel:: revert ()

重实现: 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.

使用 revertAll () to revert all pending changes for the OnManualSubmit strategy or revertRow () to revert a specific row.

另请参阅 submit (), submitAll (), revertRow (),和 revertAll ().

[slot] void QSqlTableModel:: revertAll ()

Reverts all pending changes.

另请参阅 revert (), revertRow (),和 submitAll ().

[virtual slot] 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 若成功;否则返回 false .

注意: Calling select() will revert any unsubmitted changes and remove any inserted columns.

另请参阅 setTable (), setFilter (),和 selectStatement ().

[virtual slot, 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.

返回 true 若成功;否则返回 false .

该函数在 Qt 5.0 引入。

另请参阅 select ().

[override virtual slot] bool QSqlTableModel:: submit ()

重实现: 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.

使用 submitAll () to submit all pending changes for the OnManualSubmit strategy.

返回 true 当成功时;否则返回 false 。使用 lastError () to query detailed error information.

Does not automatically repopulate the model. Submitted rows are refreshed from the database on success.

另请参阅 revert (), revertRow (), submitAll (), revertAll (),和 lastError ().

[slot] bool QSqlTableModel:: submitAll ()

Submits all pending changes and returns true on success. Returns false on error, detailed error information can be obtained with lastError ().

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.

另请参阅 revertAll () 和 lastError ().

[virtual] QSqlTableModel:: ~QSqlTableModel ()

销毁对象并释放任何分配资源。

[override virtual] void QSqlTableModel:: clear ()

重实现: QSqlQueryModel::clear ().

[override virtual] bool QSqlTableModel:: clearItemData (const QModelIndex & index )

重实现: QAbstractItemModel::clearItemData (const QModelIndex &index).

[override virtual] QVariant QSqlTableModel:: data (const QModelIndex & index , int role = Qt::DisplayRole) const

重实现: QSqlQueryModel::data (const QModelIndex &item, int role) const.

另请参阅 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 () 或 removeRows () to delete values. The model will decide depending on its edit strategy when to modify the database.

返回 true if the row was deleted; otherwise returns false .

另请参阅 removeRow () 和 removeRows ().

QSqlTableModel::EditStrategy QSqlTableModel:: editStrategy () const

Returns the current edit strategy.

另请参阅 setEditStrategy ().

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

Returns the currently set filter.

另请参阅 setFilter () 和 select ().

[override virtual] Qt::ItemFlags QSqlTableModel:: flags (const QModelIndex & index ) const

重实现: QAbstractTableModel::flags (const QModelIndex &index) const.

[override virtual] QVariant QSqlTableModel:: headerData ( int section , Qt::Orientation orientation , int role = Qt::DisplayRole) const

重实现: QSqlQueryModel::headerData (int section, Qt::Orientation orientation, int role) const.

[override virtual protected] QModelIndex QSqlTableModel:: indexInQuery (const QModelIndex & item ) const

重实现: 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.

另请参阅 QSqlQueryModel::indexInQuery ().

bool QSqlTableModel:: insertRecord ( int row , const QSqlRecord & record )

插入 record 在位置 row 。若 row is negative, the record will be appended to the end. Calls insertRows () 和 setRecord () internally.

返回 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.

另请参阅 insertRows (), removeRows (),和 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 () 和 setData () to insert values. The model will decide depending on its edit strategy when to modify the database.

返回 true if the values could be inserted, otherwise false. Error information can be retrieved with lastError ().

另请参阅 lastError (), insertRow (),和 insertRows ().

[override virtual] bool QSqlTableModel:: insertRows ( int row , int count , const QModelIndex & parent = QModelIndex())

重实现: QAbstractItemModel::insertRows (int row, int count, const QModelIndex &parent).

插入 count empty rows at position row 。注意, 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.

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.

返回 false if the parameters are out of bounds or the row cannot be inserted; otherwise returns true .

另请参阅 primeInsert () 和 insertRecord ().

bool QSqlTableModel:: isDirty (const QModelIndex & index ) const

返回 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.

index is invalid or points to a non-existing row, false is returned.

[since 5.0] bool QSqlTableModel:: isDirty () const

这是重载函数。

返回 true if the model contains modified values that have not been committed to the database, otherwise false.

该函数在 Qt 5.0 引入。

[virtual protected] QString QSqlTableModel:: orderByClause () const

Returns an SQL ORDER BY clause based on the currently set sort order.

另请参阅 setSort () 和 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.

另请参阅 setTable (), setPrimaryKey (),和 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.

该函数在 Qt 5.1 引入。

另请参阅 primaryKey ().

QSqlRecord QSqlTableModel:: record () const

这是重载函数。

It returns an empty record, having only the field names. This function can be used to retrieve the field names of a record.

另请参阅 setRecord () 和 QSqlRecord::isEmpty ().

[since 5.0] QSqlRecord QSqlTableModel:: record ( int row ) const

Returns the record at row in the model.

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.

该函数在 Qt 5.0 引入。

另请参阅 QSqlRecord::isEmpty ().

[override virtual] bool QSqlTableModel:: removeColumns ( int column , int count , const QModelIndex & parent = QModelIndex())

重实现: QSqlQueryModel::removeColumns (int column, int count, const QModelIndex &parent).

移除 count columns from the parent model, starting at index column .

Returns if the columns were successfully removed; otherwise returns false .

另请参阅 removeRows ().

[override virtual] bool QSqlTableModel:: removeRows ( int row , int count , const QModelIndex & parent = QModelIndex())

重实现: QAbstractItemModel::removeRows (int row, int count, const QModelIndex &parent).

移除 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 () 被调用。

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 () 信号被发射。

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 ().

另请参阅 removeColumns () 和 insertRows ().

[virtual] void QSqlTableModel:: revertRow ( int row )

Reverts all changes for the specified row .

另请参阅 revert (), revertAll (), submit (),和 submitAll ().

[override virtual] int QSqlTableModel:: rowCount (const QModelIndex & parent = QModelIndex()) const

重实现: QSqlQueryModel::rowCount (const QModelIndex &parent) const.

[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 子句。

另请参阅 filter () 和 orderByClause ().

[override virtual] bool QSqlTableModel:: setData (const QModelIndex & index , const QVariant & value , int role = Qt::EditRole)

重实现: 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.

返回 true if value is equal to the current value. However, the value will not be submitted to the database.

返回 true if the value could be set or false on error, for example if index is out of bounds.

返回 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 .

另请参阅 editStrategy (), data (), submit (), submitAll (),和 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.

另请参阅 editStrategy () 和 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 () 被调用。

另请参阅 filter (), select (), selectStatement (),和 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 ().

另请参阅 primaryKey () 和 QSqlDatabase::primaryIndex ().

[protected] void QSqlTableModel:: setQuery (const QSqlQuery & query )

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

另请参阅 selectStatement ().

bool QSqlTableModel:: setRecord ( int row , const QSqlRecord & values )

Applies values 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 使用 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.

返回 true if all the values could be set; otherwise returns false.

另请参阅 record () 和 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 ().

另请参阅 sort (), select (),和 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 ().

另请参阅 select (), setFilter (),和 lastError ().

[override virtual] void QSqlTableModel:: sort ( int column , Qt::SortOrder order )

重实现: 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.

另请参阅 setSort (), select (),和 orderByClause ().

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 。返回 true 若成功;否则返回 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 ().

另请参阅 QSqlRecord::isGenerated () 和 setData ().