|
|
||||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Objectcom.trolltech.qt.QSignalEmitter
com.trolltech.qt.QtJambiObject
com.trolltech.qt.core.QObject
com.trolltech.qt.core.QAbstractItemModel
com.trolltech.qt.gui.QAbstractTableModel
com.trolltech.qt.sql.QSqlQueryModel
com.trolltech.qt.sql.QSqlTableModel
public class QSqlTableModel
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.
Model Example
,
Cached Table ExampleNested 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()
Clears the model and releases any acquired resource. |
java.lang.Object |
data(QModelIndex idx,
int role)
Returns the value for the specified item and role. |
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)
Returns the item flags for the given index. |
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)
Returns the header data for the given role in the section of the header with the specified orientation. |
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)
If the database supports returning the size of a query (see QSqlDriver::hasFeature()), the amount of rows of the current query is returned. |
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 |
---|
public final QSignalEmitter.Signal1<java.lang.Integer> beforeDelete
This signal is emitted before the row is deleted.
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.
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.
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.
Constructor Detail |
---|
public QSqlTableModel(QObject parent)
Equivalent to QSqlTableModel(parent, QSqlDatabase()).
public QSqlTableModel()
Equivalent to QSqlTableModel(0, QSqlDatabase()).
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 |
---|
public final QSqlDatabase database()
Returns a pointer to the used QSqlDatabase or 0 if no database was set.
public final QSqlTableModel.EditStrategy editStrategy()
Returns the current edit strategy.
public final int fieldIndex(java.lang.String fieldName)
Returns the index of the field fieldName.
public final java.lang.String filter()
Returns the currently set filter.
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.
indexInQuery
in class QSqlQueryModel
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.
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.
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.
public final void revertAll()
Reverts all pending changes.
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.
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.
setQuery
in class QSqlQueryModel
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.
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.
public final java.lang.String tableName()
Returns the name of the currently selected table.
public void clear()
Clears the model and releases any acquired resource.
clear
in class QSqlQueryModel
public java.lang.Object data(QModelIndex idx, int role)
Returns the value for the specified item and role.
If item is out of bounds or if an error occurred, an invalid QVariant is returned.
data
in class QSqlQueryModel
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.
public Qt.ItemFlags flags(QModelIndex index)
Returns the item flags for the given index.
The base class implementation returns a combination of flags that enables the item (ItemIsEnabled) and allows it to be selected (ItemIsSelectable).
flags
in class QAbstractItemModel
public java.lang.Object headerData(int section, Qt.Orientation orientation, int role)
Returns the header data for the given role in the section of the header with the specified orientation.
headerData
in class QSqlQueryModel
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.
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.
insertRows
in class QAbstractItemModel
protected java.lang.String orderByClause()
Returns an SQL ORDER BY clause based on the currently set sort order.
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.
removeColumns
in class QSqlQueryModel
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.
removeRows
in class QAbstractItemModel
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.
revert
in class QAbstractItemModel
public void revertRow(int row)
Reverts all changes for the specified row.
public int rowCount(QModelIndex parent)
If the database supports returning the size of a query (see QSqlDriver::hasFeature()), the amount of rows of the current query is returned. Otherwise, returns the amount of rows currently cached on the client.
parent should always be an invalid QModelIndex.
rowCount
in class QSqlQueryModel
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.
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.
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.
setData
in class QAbstractItemModel
public void setEditStrategy(QSqlTableModel.EditStrategy strategy)
Sets the strategy for editing values in the database to strategy.
This will revert any pending changes.
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.
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.
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.
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.
sort
in class QAbstractItemModel
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.
submit
in class QAbstractItemModel
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().
public static QSqlTableModel fromNativePointer(QNativePointer nativePointer)
nativePointer
- the QNativePointer of which object should be returned.
|
|
||||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |