def _handleNewColumns(self, tableName:str, existingSchema: QSqlRecord,
newSchema: QSqlRecord):
"""
Compares the existing schema with the new schema to work out what
changes need to be made.
Note: To modify a table column or insert a new column between existing
columns (as opposed to just appending at the end), a schema upgrade
routine will need to be written.
"""
i = 0
while i < min(existingSchema.count(), newSchema.count()):
if existingSchema.field(i) != newSchema.field(i):
raise UpgradeException("New schema cannot modify field " +
"properties or ordering without a schema" +
" upgrade routine.")
i += 1
if newSchema.count() > existingSchema.count():
while i < newSchema.count():
self._query.AlterTableAddColumn(tableName, newSchema.field(i))
i += 1
elif newSchema.count() < existingSchema.count() and self._dangerousMode:
while i < existingSchema.count():
self._query.AlterTableDropColumn(tableName, existingSchema.field(i))
i += 1
def _setDefaultColumn(self, model, db, record: QtSql.QSqlRecord):
'''根据一个record对象设置默认ViewColumns'''
self.__model = model
for i in range(record.count()):
fld = record.field(i)
fn = fld.name()
vc = ViewColumn(model, fn, fn)
vc.parent = self
self._list.append(vc)
self._setViewColumnAlighAndFormatString(vc)