com.trolltech.qt.sql
Class QSqlTableModel

java.lang.Object
  extended by com.trolltech.qt.internal.QSignalEmitterInternal
      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.EditStrategy.OnManualSubmit);
        model.select();
        model.removeColumn(0); // don't show the ID
        model.setHeaderData(0, Qt.Orientation.Horizontal, tr("Name"));
        model.setHeaderData(1, Qt.Orientation.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 = new QSqlTableModel();
        model.setTable("employee");
        String 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.

See also:
QSqlRelationalTableModel, QSqlQuery, Model/View Programming, Table Model Example, and 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.AbstractSignal, QSignalEmitter.PrivateSignal0, QSignalEmitter.PrivateSignal1, QSignalEmitter.PrivateSignal2, QSignalEmitter.PrivateSignal3, QSignalEmitter.PrivateSignal4, QSignalEmitter.PrivateSignal5, QSignalEmitter.PrivateSignal6, QSignalEmitter.PrivateSignal7, QSignalEmitter.PrivateSignal8, QSignalEmitter.PrivateSignal9, QSignalEmitter.Signal0, QSignalEmitter.Signal1, QSignalEmitter.Signal2, QSignalEmitter.Signal3, QSignalEmitter.Signal4, QSignalEmitter.Signal5, QSignalEmitter.Signal6, QSignalEmitter.Signal7, QSignalEmitter.Signal8, QSignalEmitter.Signal9
 
Nested classes/interfaces inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
com.trolltech.qt.internal.QSignalEmitterInternal.AbstractSignalInternal
 
Field Summary
 QSignalEmitter.Signal1 beforeDelete
          This signal takes 1 generic argument(s).
 QSignalEmitter.Signal1 beforeInsert
          This signal takes 1 generic argument(s).
 QSignalEmitter.Signal2 beforeUpdate
          This signal takes 2 generic argument(s).
 QSignalEmitter.Signal2 primeInsert
          This signal takes 2 generic argument(s).
 
Fields inherited from class com.trolltech.qt.core.QAbstractItemModel
columnsAboutToBeInserted, columnsAboutToBeRemoved, columnsInserted, columnsRemoved, dataChanged, headerDataChanged, layoutAboutToBeChanged, layoutChanged, modelAboutToBeReset, modelReset, rowsAboutToBeInserted, rowsAboutToBeRemoved, rowsInserted, rowsRemoved
 
Fields inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
currentSender
 
Constructor Summary
QSqlTableModel()
          Creates an empty QSqlTableModel and sets the parent to parent and the database connection to db.
QSqlTableModel(QObject parent)
          Creates an empty QSqlTableModel and sets the parent to parent and the database connection to db.
QSqlTableModel(QObject parent, QSqlDatabase db)
          Creates an empty QSqlTableModel and sets the parent to parent and the database connection to db.
 
Method Summary
 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.
 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 isDirty(com.trolltech.qt.core.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.
 void revertAll()
          Reverts all pending changes.
 void revertRow(int row)
          Reverts all changes for the specified row.
 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.
 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.
 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.
 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
clear, indexInQuery, lastError, query, queryChange, record, record, setLastError, setQuery, setQuery, setQuery
 
Methods inherited from class com.trolltech.qt.core.QAbstractItemModel
beginInsertColumns, beginInsertRows, beginRemoveColumns, beginRemoveRows, buddy, canFetchMore, changePersistentIndex, changePersistentIndexList, columnCount, columnCount, createIndex, createIndex, createIndex, data, data, data, data, dropMimeData, endInsertColumns, endInsertRows, endRemoveColumns, endRemoveRows, fetchMore, flags, hasChildren, hasChildren, hasIndex, hasIndex, headerData, headerData, index, index, insertColumn, insertColumn, insertColumns, insertColumns, insertRow, insertRow, insertRows, insertRows, itemData, match, match, match, match, mimeData, mimeTypes, parent, persistentIndexList, removeColumn, removeColumn, removeColumns, removeColumns, removeRow, removeRow, removeRows, removeRows, reset, revert, rowCount, rowCount, setData, setData, setData, setData, setHeaderData, setHeaderData, setItemData, setSupportedDragActions, setSupportedDragActions, sibling, sort, sort, span, submit, supportedDragActions, supportedDropActions
 
Methods inherited from class com.trolltech.qt.core.QObject
childEvent, children, connectSlotsByName, customEvent, disposeLater, dumpObjectInfo, dumpObjectTree, dynamicPropertyNames, event, eventFilter, findChild, findChild, findChild, findChildren, findChildren, findChildren, findChildren, indexOfProperty, installEventFilter, isWidgetType, killTimer, moveToThread, objectName, parent, properties, property, removeEventFilter, setObjectName, setParent, setProperty, startTimer, timerEvent, toString, userProperty
 
Methods inherited from class com.trolltech.qt.QtJambiObject
dispose, disposed, equals, finalize, reassignNativeResources, tr, tr, tr
 
Methods inherited from class com.trolltech.qt.QSignalEmitter
blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread
 
Methods inherited from class com.trolltech.qt.internal.QSignalEmitterInternal
__qt_signalInitialization
 
Methods inherited from class java.lang.Object
clone, getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface com.trolltech.qt.QtJambiInterface
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership
 

Field Detail

beforeDelete

public final QSignalEmitter.Signal1 beforeDelete

This signal takes 1 generic argument(s). We list their type and the name they go by in the description of this signal. <java.lang.Integer(named: row)>:

This signal is emitted by deleteRowFromTable() before the row is deleted from the currently active database table.


beforeInsert

public final QSignalEmitter.Signal1 beforeInsert

This signal takes 1 generic argument(s). We list their type and the name they go by in the description of this signal. <com.trolltech.qt.sql.QSqlRecord(named: 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.


beforeUpdate

public final QSignalEmitter.Signal2 beforeUpdate

This signal takes 2 generic argument(s). We list their type and the name they go by in the description of this signal. <java.lang.Integer(named: row), com.trolltech.qt.sql.QSqlRecord(named: 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:
QSqlRecord::isGenerated().


primeInsert

public final QSignalEmitter.Signal2 primeInsert

This signal takes 2 generic argument(s). We list their type and the name they go by in the description of this signal. <java.lang.Integer(named: row), com.trolltech.qt.sql.QSqlRecord(named: 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.

Constructor Detail

QSqlTableModel

public QSqlTableModel(QObject parent)
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 .


QSqlTableModel

public QSqlTableModel()
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 .


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(), and select().


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(), and removeRows().


isDirty

public final boolean isDirty(com.trolltech.qt.core.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(), and QSqlDatabase::primaryIndex().


revertAll

public final void revertAll()
Reverts all pending changes.

See also:
revert(), revertRow(), and 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(), and QSqlDatabase::primaryIndex().


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(), and lastError().


tableName

public final java.lang.String tableName()
Returns the name of the currently selected table.


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(), and removeRows().


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(), and insertRows().


orderByClause

protected java.lang.String orderByClause()
Returns an SQL ORDER BY clause based on the currently set sort order.

See also:
setSort(), and selectStatement().


revertRow

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

See also:
revert(), revertAll(), submit(), and submitAll().


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(), and 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(), and orderByClause().


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(), and 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(), and 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(), and 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(), and 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(), and setData().