我想生成一个足够简单的应用程序，它使用QTreeView小部件显示来自SQLite3（平面）表的分层数据，使用QDataWidgetMapper填充一些lineedit字段，允许用户编辑，然后更新表。简单＆amp;基本的（大多数！）。
我一直在努力，以下过程是最好的方法：
dict操纵它来动态创建节点，父项和子项 - 对于每个dict条目，使用关联父项生成“节点”）我意识到如果我只是使用QTableView或QListView，我不需要自定义模型，可以直接写回数据库。我上面概述的过程似乎意味着必须保留两组数据 - 即SQLite表和自定义QAIM，并确保它们都保持最新。这对我来说似乎有点麻烦，我确信在QTreeView直接从SQLite表中获取数据时必须有更好的方法 - 显然需要一些操作来将平面数据转换为分层数据。
当然，我想知道我是否完全误解了QAbstractItemModel与QSQL *模型之间的关系，而我我是否因为无知而过度复杂化了？
由于
答案 0 :(得分：2)
您想要的是一个代理模型，它充当QSql*Model与视图之间的桥梁。为此，您需要继承QAbstractProxyModel。您必须采用一致的方法在代理模型中查找父子关系并将它们映射到源模型，这样可能需要在代理模型中保留一些计数。
当您对QAbstractProxyModel进行子类化时，您至少需要重新定义这些方法：
另外，请记住QAbstractProxyModel不会自动传播信号。因此，为了让视图了解源模型中的更改（如插入，删除，更新），您需要在代理模型中传递它们（当然，更新代理模型中的映射）。
这需要一些工作，但最终你会有一个更灵活的结构。它将消除您为同步数据库和自定义QAbstractItemModel所需要做的所有事情。
修改
自定义代理模型，它根据给定列对平面模型中的项进行分组：
import sys
from collections import namedtuple
import random
from PyQt4 import QtCore, QtGui
groupItem = namedtuple("groupItem",["name","children","index"])
rowItem = namedtuple("rowItem",["groupIndex","random"])
class GrouperProxyModel(QtGui.QAbstractProxyModel):
def __init__(self, parent=None):
super(GrouperProxyModel, self).__init__(parent)
self._rootItem = QtCore.QModelIndex()
self._groups = [] # list of groupItems
self._groupMap = {} # map of group names to group indexes
self._groupIndexes = [] # list of groupIndexes for locating group row
self._sourceRows = [] # map of source rows to group index
self._groupColumn = 0 # grouping column.
def setSourceModel(self, source, groupColumn=0):
super(GrouperProxyModel, self).setSourceModel(source)
# connect signals
self.sourceModel().columnsAboutToBeInserted.connect(self.columnsAboutToBeInserted.emit)
self.sourceModel().columnsInserted.connect(self.columnsInserted.emit)
self.sourceModel().columnsAboutToBeRemoved.connect(self.columnsAboutToBeRemoved.emit)
self.sourceModel().columnsRemoved.connect(self.columnsRemoved.emit)
self.sourceModel().rowsInserted.connect(self._rowsInserted)
self.sourceModel().rowsRemoved.connect(self._rowsRemoved)
self.sourceModel().dataChanged.connect(self._dataChanged)
# set grouping
self.groupBy(groupColumn)
def rowCount(self, parent):
if parent == self._rootItem:
# root level
return len(self._groups)
elif parent.internalPointer() == self._rootItem:
# children level
return len(self._groups[parent.row()].children)
else:
return 0
def columnCount(self, parent):
if self.sourceModel():
return self.sourceModel().columnCount(QtCore.QModelIndex())
else:
return 0
def index(self, row, column, parent):
if parent == self._rootItem:
# this is a group
return self.createIndex(row,column,self._rootItem)
elif parent.internalPointer() == self._rootItem:
return self.createIndex(row,column,self._groups[parent.row()].index)
else:
return QtCore.QModelIndex()
def parent(self, index):
parent = index.internalPointer()
if parent == self._rootItem:
return self._rootItem
else:
parentRow = self._getGroupRow(parent)
return self.createIndex(parentRow,0,self._rootItem)
def data(self, index, role):
if role == QtCore.Qt.DisplayRole:
parent = index.internalPointer()
if parent == self._rootItem:
return self._groups[index.row()].name
else:
parentRow = self._getGroupRow(parent)
sourceRow = self._sourceRows.index(self._groups[parentRow].children[index.row()])
sourceIndex = self.createIndex(sourceRow, index.column(), 0)
return self.sourceModel().data(sourceIndex, role)
return None
def flags(self, index):
return QtCore.Qt.ItemIsEnabled | QtCore.Qt.ItemIsSelectable
def headerData(self, section, orientation, role):
return self.sourceModel().headerData(section, orientation, role)
def mapToSource(self, index):
if not index.isValid():
return QtCore.QModelIndex()
parent = index.internalPointer()
if not parent.isValid():
return QtCore.QModelIndex()
elif parent == self._rootItem:
return QtCore.QModelIndex()
else:
rowItem_ = self._groups[parent.row()].children[index.row()]
sourceRow = self._sourceRows.index(rowItem_)
return self.createIndex(sourceRow, index.column(), QtCore.QModelIndex())
def mapFromSource(self, index):
rowItem_ = self._sourceRows[index.row()]
groupRow = self._getGroupRow(rowItem_.groupIndex)
itemRow = self._groups[groupRow].children.index(rowItem_)
return self.createIndex(itemRow,index.column(),self._groupIndexes[groupRow])
def _clearGroups(self):
self._groupMap = {}
self._groups = []
self._sourceRows = []
def groupBy(self,column=0):
self.beginResetModel()
self._clearGroups()
self._groupColumn = column
sourceModel = self.sourceModel()
for row in range(sourceModel.rowCount(QtCore.QModelIndex())):
groupName = sourceModel.data(self.createIndex(row,column,0),
QtCore.Qt.DisplayRole)
groupIndex = self._getGroupIndex(groupName)
rowItem_ = rowItem(groupIndex,random.random())
self._groups[groupIndex.row()].children.append(rowItem_)
self._sourceRows.append(rowItem_)
self.endResetModel()
def _getGroupIndex(self, groupName):
""" return the index for a group denoted with name.
if there is no group with given name, create and then return"""
if groupName in self._groupMap:
return self._groupMap[groupName]
else:
groupRow = len(self._groupMap)
groupIndex = self.createIndex(groupRow,0,self._rootItem)
self._groupMap[groupName] = groupIndex
self._groups.append(groupItem(groupName,[],groupIndex))
self._groupIndexes.append(groupIndex)
self.layoutChanged.emit()
return groupIndex
def _getGroupRow(self, groupIndex):
for i,x in enumerate(self._groupIndexes):
if id(groupIndex)==id(x):
return i
return 0
def _rowsInserted(self, parent, start, end):
for row in range(start, end+1):
groupName = self.sourceModel().data(self.createIndex(row,self._groupColumn,0),
QtCore.Qt.DisplayRole)
groupIndex = self._getGroupIndex(groupName)
self._getGroupRow(groupIndex)
groupItem_ = self._groups[self._getGroupRow(groupIndex)]
rowItem_ = rowItem(groupIndex,random.random())
groupItem_.children.append(rowItem_)
self._sourceRows.insert(row, rowItem_)
self.layoutChanged.emit()
def _rowsRemoved(self, parent, start, end):
for row in range(start, end+1):
rowItem_ = self._sourceRows[start]
groupIndex = rowItem_.groupIndex
groupItem_ = self._groups[self._getGroupRow(groupIndex)]
childrenRow = groupItem_.children.index(rowItem_)
groupItem_.children.pop(childrenRow)
self._sourceRows.pop(start)
if not len(groupItem_.children):
# remove the group
groupRow = self._getGroupRow(groupIndex)
groupName = self._groups[groupRow].name
self._groups.pop(groupRow)
self._groupIndexes.pop(groupRow)
del self._groupMap[groupName]
self.layoutChanged.emit()
def _dataChanged(self, topLeft, bottomRight):
topRow = topLeft.row()
bottomRow = bottomRight.row()
sourceModel = self.sourceModel()
# loop through all the changed data
for row in range(topRow,bottomRow+1):
oldGroupIndex = self._sourceRows[row].groupIndex
oldGroupItem = self._groups[self._getGroupRow(oldGroupIndex)]
newGroupName = sourceModel.data(self.createIndex(row,self._groupColumn,0),QtCore.Qt.DisplayRole)
if newGroupName != oldGroupItem.name:
# move to new group...
newGroupIndex = self._getGroupIndex(newGroupName)
newGroupItem = self._groups[self._getGroupRow(newGroupIndex)]
rowItem_ = self._sourceRows[row]
newGroupItem.children.append(rowItem_)
# delete from old group
oldGroupItem.children.remove(rowItem_)
if not len(oldGroupItem.children):
# remove the group
groupRow = self._getGroupRow(oldGroupItem.index)
groupName = oldGroupItem.name
self._groups.pop(groupRow)
self._groupIndexes.pop(groupRow)
del self._groupMap[groupName]
self.layoutChanged.emit()