com.trolltech.qt.sql
Class QSqlTableModel

java.lang.Object
  extended by com.trolltech.qt.QSignalEmitter
      extended by com.trolltech.qt.QtJambiObject
          extended by com.trolltech.qt.core.QObject
              extended by com.trolltech.qt.core.QAbstractItemModel
                  extended by com.trolltech.qt.gui.QAbstractTableModel
                      extended by com.trolltech.qt.sql.QSqlQueryModel
                          extended by com.trolltech.qt.sql.QSqlTableModel
All Implemented Interfaces:
QtJambiInterface
Direct Known Subclasses:
QSqlRelationalTableModel

public class QSqlTableModel
extends QSqlQueryModel

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 build 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->removeColumn(0); // don't show the ID
        model->setHeaderData(0, Qt::Horizontal, tr("Name"));
        model->setHeaderData(1, Qt::Horizontal, tr("Salary"));

        QTableView *view = new QTableView;
        view->setModel(model);
        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");
        QString name = model.record(4).value("name").toString();

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 sql/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.

The QSQLITE driver locks for updates until a select is finished. QSqlTableModel fetches data (QSqlQuery::fetchMore()) as needed; this may cause the updates to time out.

See Also:
QSqlRelationalTableModel, QSqlQuery, Model/View Programming, Model Example, Cached Table Example

Nested Class Summary
static class QSqlTableModel.EditStrategy
          This enum type describes which strategy to choose when editing values in the database.
 
Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter
QSignalEmitter.Signal0, QSignalEmitter.Signal1<A>, QSignalEmitter.Signal2<A,B>, QSignalEmitter.Signal3<A,B,C>, QSignalEmitter.Signal4<A,B,C,D>, QSignalEmitter.Signal5<A,B,C,D,E>, QSignalEmitter.Signal6<A,B,C,D,E,F>, QSignalEmitter.Signal7<A,B,C,D,E,F,G>, QSignalEmitter.Signal8<A,B,C,D,E,F,G,H>, QSignalEmitter.Signal9<A,B,C,D,E,F,G,H,I>
 
Field Summary
 QSignalEmitter.Signal1<java.lang.Integer> beforeDelete
          This signal is emitted before the row is deleted.
 QSignalEmitter.Signal1<QSqlRecord> beforeInsert
          This signal is emitted before a new row is inserted.
 QSignalEmitter.Signal2<java.lang.Integer,QSqlRecord> beforeUpdate
          This signal is emitted before the row is updated with the values from record.
 QSignalEmitter.Signal2<java.lang.Integer,QSqlRecord> primeInsert
          This signal is emitted when an insertion is initiated in the given row.
 
Fields inherited from class com.trolltech.qt.core.QAbstractItemModel
dataChanged, headerDataChanged, layoutAboutToBeChanged, layoutChanged
 
Constructor Summary
QSqlTableModel()
          Equivalent to QSqlTableModel(0, QSqlDatabase()).
QSqlTableModel(QObject parent)
          Equivalent to QSqlTableModel(parent, QSqlDatabase()).
QSqlTableModel(QObject parent, QSqlDatabase db)
          Creates an empty QSqlTableModel and sets the parent to parent and the database connection to db.
 
Method Summary
 void clear()
          This function is reimplemented for internal reasons.
 java.lang.Object data(QModelIndex idx, int role)
          This function is reimplemented for internal reasons.
 QSqlDatabase database()
          Returns a pointer to the used QSqlDatabase or 0 if no database was set.
protected  boolean deleteRowFromTable(int row)
          Deletes the given row from the currently active database table.
 QSqlTableModel.EditStrategy editStrategy()
          Returns the current edit strategy.
 int fieldIndex(java.lang.String fieldName)
          Returns the index of the field fieldName.
 java.lang.String filter()
          Returns the currently set filter.
 Qt.ItemFlags flags(QModelIndex index)
          This function is reimplemented for internal reasons.
static QSqlTableModel fromNativePointer(QNativePointer nativePointer)
          This function returns the QSqlTableModel instance pointed to by nativePointer
 java.lang.Object headerData(int section, Qt.Orientation orientation, int role)
          This function is reimplemented for internal reasons.
protected  QModelIndex indexInQuery(QModelIndex item)
          Returns the index of the value in the database result set for the given item in the model.
 boolean insertRecord(int row, QSqlRecord record)
          Inserts the record after row.
protected  boolean insertRowIntoTable(QSqlRecord values)
          Inserts the values values into the currently active database table.
 boolean insertRows(int row, int count, QModelIndex parent)
          Inserts count empty rows at position row.
 boolean isDirty(QModelIndex index)
          Returns true if the value at the index index is dirty, otherwise false.
protected  java.lang.String orderByClause()
          Returns an SQL ORDER BY clause based on the currently set sort order.
 QSqlIndex primaryKey()
          Returns the primary key for the current table, or an empty QSqlIndex if the table is not set or has no primary key.
 boolean removeColumns(int column, int count, QModelIndex parent)
          Removes count columns from the parent model, starting at index column.
 boolean removeRows(int row, int count, QModelIndex parent)
          Removes count rows starting at row.
 void revert()
          This reimplemented slot is called by the item delegates when the user canceled editing the current row.
 void revertAll()
          Reverts all pending changes.
 void revertRow(int row)
          Reverts all changes for the specified row.
 int rowCount(QModelIndex parent)
          This function is reimplemented for internal reasons.
 boolean 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.
protected  java.lang.String selectStatement()
          Returns the SQL SELECT statement used internally to populate the model.
 boolean setData(QModelIndex index, java.lang.Object value, int role)
          Sets the data for the item index for the role role to value.
 void setEditStrategy(QSqlTableModel.EditStrategy strategy)
          Sets the strategy for editing values in the database to strategy.
 void setFilter(java.lang.String filter)
          Sets the current filter to filter.
protected  void setPrimaryKey(QSqlIndex key)
          Protected method that allows subclasses to set the primary key to key.
 void setQuery(QSqlQuery query)
          This function simply calls QSqlQueryModel::setQuery(query).
 boolean setRecord(int row, QSqlRecord record)
          Sets the values at the specified row to the values of record.
 void setSort(int column, Qt.SortOrder order)
          Sets the sort order for column to order.
 void setTable(java.lang.String tableName)
          Sets the database table on which the model operates to tableName.
 void sort(int column, Qt.SortOrder order)
          Sorts the data by column with the sort order order.
 boolean submit()
          This reimplemented slot is called by the item delegates when the user stopped editing the current row.
 boolean submitAll()
          Submits all pending changes and returns true on success.
 java.lang.String tableName()
          Returns the name of the currently selected table.
protected  boolean updateRowInTable(int row, QSqlRecord values)
          Updates the given row in the currently active database table with the specified values.
 
Methods inherited from class com.trolltech.qt.sql.QSqlQueryModel
canFetchMore, columnCount, fetchMore, insertColumns, lastError, query, queryChange, record, record, setHeaderData, setLastError, setQuery, setQuery
 
Methods inherited from class com.trolltech.qt.gui.QAbstractTableModel
dropMimeData, hasChildren, index, parent
 
Methods inherited from class com.trolltech.qt.core.QAbstractItemModel
beginInsertColumns, beginInsertRows, beginRemoveColumns, beginRemoveRows, buddy, changePersistentIndex, changePersistentIndexList, columnCount, createIndex, createIndex, createIndex, data, data, data, decodeData, encodeData, endInsertColumns, endInsertRows, endRemoveColumns, endRemoveRows, hasChildren, hasIndex, hasIndex, headerData, index, insertColumn, insertColumn, insertColumns, insertRow, insertRow, insertRows, itemData, match, match, match, match, mimeData, mimeTypes, persistentIndexList, removeColumn, removeColumn, removeColumns, removeRow, removeRow, removeRows, reset, rowCount, setData, setData, setData, setHeaderData, setItemData, setSupportedDragActions, setSupportedDragActions, sibling, sort, span, supportedDragActions, supportedDropActions
 
Methods inherited from class com.trolltech.qt.core.QObject
blockSignals, childEvent, children, connectSlotsByName, customEvent, disposeLater, dumpObjectInfo, dumpObjectTree, dynamicPropertyNames, event, eventFilter, findChild, findChild, findChild, findChildren, findChildren, findChildren, findChildren, installEventFilter, isWidgetType, killTimer, moveToThread, objectName, parent, property, removeEventFilter, setObjectName, setParent, setProperty, signalsBlocked, startTimer, thread, timerEvent
 
Methods inherited from class com.trolltech.qt.QtJambiObject
dispose, disposed, finalize, reassignNativeResources, tr, tr, tr
 
Methods inherited from class com.trolltech.qt.QSignalEmitter
disconnect, disconnect, signalSender
 
Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface com.trolltech.qt.QtJambiInterface
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership
 

Field Detail

beforeDelete

public final QSignalEmitter.Signal1<java.lang.Integer> beforeDelete

This signal is emitted before the row is deleted.

Compatible Slot Signatures:
void mySlot(int row)
void mySlot()


beforeInsert

public final QSignalEmitter.Signal1<QSqlRecord> beforeInsert

This signal is emitted before a new row is inserted. The values that are about to be inserted are stored in record and can be modified before they will be inserted.

Compatible Slot Signatures:
void mySlot(com.trolltech.qt.sql.QSqlRecord record)
void mySlot()


beforeUpdate

public final QSignalEmitter.Signal2<java.lang.Integer,QSqlRecord> beforeUpdate

This signal is emitted before the row is updated 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.

Compatible Slot Signatures:
void mySlot(int row, com.trolltech.qt.sql.QSqlRecord record)
void mySlot(int row)
void mySlot()
See Also:
QSqlRecord::isGenerated


primeInsert

public final QSignalEmitter.Signal2<java.lang.Integer,QSqlRecord> primeInsert

This signal is emitted when an insertion is initiated in the given row. The record parameter can be written to (since it is a reference), for example to populate some fields with default values.

Compatible Slot Signatures:
void mySlot(int row, com.trolltech.qt.sql.QSqlRecord record)
void mySlot(int row)
void mySlot()

Constructor Detail

QSqlTableModel

public QSqlTableModel(QObject parent)

Equivalent to QSqlTableModel(parent, QSqlDatabase()).


QSqlTableModel

public QSqlTableModel()

Equivalent to QSqlTableModel(0, QSqlDatabase()).


QSqlTableModel

public QSqlTableModel(QObject parent,
                      QSqlDatabase db)

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.

Method Detail

database

public final QSqlDatabase database()

Returns a pointer to the used QSqlDatabase or 0 if no database was set.


editStrategy

public final QSqlTableModel.EditStrategy editStrategy()

Returns the current edit strategy.

See Also:
setEditStrategy

fieldIndex

public final int fieldIndex(java.lang.String fieldName)

Returns the index of the field fieldName.


filter

public final java.lang.String filter()

Returns the currently set filter.

See Also:
setFilter, select

indexInQuery

protected final QModelIndex indexInQuery(QModelIndex item)

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.

Overrides:
indexInQuery in class QSqlQueryModel
See Also:
QSqlQueryModel::indexInQuery

insertRecord

public final boolean insertRecord(int row,
                                  QSqlRecord record)

Inserts the record after row. If row is negative, the record will be appended to the end. Calls insertRows and setRecord internally.

Returns true if the row could be inserted, otherwise false.

See Also:
insertRows, removeRows

isDirty

public final boolean isDirty(QModelIndex index)

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.


primaryKey

public final QSqlIndex primaryKey()

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, QSqlDatabase::primaryIndex

revertAll

public final void revertAll()

Reverts all pending changes.

See Also:
revert, revertRow, submitAll

setPrimaryKey

protected final void setPrimaryKey(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:
primaryKey, QSqlDatabase::primaryIndex

setQuery

public final void setQuery(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.

Overrides:
setQuery in class QSqlQueryModel
See Also:
selectStatement

setRecord

public final boolean setRecord(int row,
                               QSqlRecord record)

Sets the values at the specified row to the values of record. Returns true if all the values could be set; otherwise returns false.

See Also:
record

submitAll

public final boolean submitAll()

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

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 again without losing data.

See Also:
revertAll, lastError

tableName

public final java.lang.String tableName()

Returns the name of the currently selected table.


clear

public void clear()

This function is reimplemented for internal reasons.

Overrides:
clear in class QSqlQueryModel

data

public java.lang.Object data(QModelIndex idx,
                             int role)

This function is reimplemented for internal reasons.

Overrides:
data in class QSqlQueryModel
See Also:
setData

deleteRowFromTable

protected boolean 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:
removeRow, removeRows

flags

public Qt.ItemFlags flags(QModelIndex index)

This function is reimplemented for internal reasons.

Overrides:
flags in class QAbstractItemModel
See Also:
Qt::ItemFlags

headerData

public java.lang.Object headerData(int section,
                                   Qt.Orientation orientation,
                                   int role)

This function is reimplemented for internal reasons.

Overrides:
headerData in class QSqlQueryModel
See Also:
setHeaderData

insertRowIntoTable

protected boolean insertRowIntoTable(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:
lastError, insertRow, insertRows

insertRows

public boolean insertRows(int row,
                          int count,
                          QModelIndex parent)

Inserts count empty rows at position row. Note that parent must be invalid, since this model does not support parent-child relations.

Only one row at a time can be inserted when using the OnFieldChange or OnRowChange update strategies.

The primeInsert signal will be emitted for each new row. Connect to it if you want to initialize the new row with default values.

Returns false if the parameters are out of bounds; otherwise returns true.

Overrides:
insertRows in class QAbstractItemModel
See Also:
primeInsert, insertRecord

orderByClause

protected java.lang.String orderByClause()

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

See Also:
setSort, selectStatement

removeColumns

public boolean removeColumns(int column,
                             int count,
                             QModelIndex parent)

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

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

Overrides:
removeColumns in class QSqlQueryModel
See Also:
removeRows

removeRows

public boolean removeRows(int row,
                          int count,
                          QModelIndex parent)

Removes count rows starting at row. Since this model does not support hierarchical structures, parent must be an invalid model index.

Emits the beforeDelete signal before a row is deleted.

Returns true if all rows could be removed; otherwise returns false. Detailed error information can be retrieved using lastError.

Overrides:
removeRows in class QAbstractItemModel
See Also:
removeColumns, insertRows

revert

public void 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. Does nothing for the other edit strategies.

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

Overrides:
revert in class QAbstractItemModel
See Also:
submit, submitAll, revertRow, revertAll

revertRow

public void revertRow(int row)

Reverts all changes for the specified row.

See Also:
revert, revertAll, submit, submitAll

rowCount

public int rowCount(QModelIndex parent)

This function is reimplemented for internal reasons.

Overrides:
rowCount in class QSqlQueryModel
See Also:
canFetchMore, QSqlDriver::hasFeature

select

public boolean 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.

See Also:
setTable, setFilter, selectStatement

selectStatement

protected java.lang.String selectStatement()

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

public boolean setData(QModelIndex index,
                       java.lang.Object value,
                       int role)

Sets the data for the item index for the role role to value. Depending on the edit strategy, the value might be applied to the database at once or cached in the model.

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

Overrides:
setData in class QAbstractItemModel
See Also:
editStrategy, data, submit, submitAll, revertRow

setEditStrategy

public void setEditStrategy(QSqlTableModel.EditStrategy strategy)

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

This will revert any pending changes.

See Also:
editStrategy, revertAll

setFilter

public void setFilter(java.lang.String 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:
filter, select, selectStatement, orderByClause

setSort

public void 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:
sort, select, orderByClause

setTable

public void setTable(java.lang.String 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:
select, setFilter, lastError

sort

public void 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.

Overrides:
sort in class QAbstractItemModel
See Also:
setSort, select, orderByClause

submit

public boolean 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.

On success the model will be repopulated. Any views presenting it will lose their selections.

Overrides:
submit in class QAbstractItemModel
See Also:
revert, revertRow, submitAll, revertAll, lastError

updateRowInTable

protected boolean updateRowInTable(int row,
                                   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:
QSqlRecord::isGenerated, setData

fromNativePointer

public static QSqlTableModel fromNativePointer(QNativePointer nativePointer)
This function returns the QSqlTableModel instance pointed to by nativePointer

Parameters:
nativePointer - the QNativePointer of which object should be returned.