题目描述：
本次实验为连接数据库的实验，并对数据库进行一些简单的操作，要实现的基本功能如下所示，要能连接并展现数据库里的数据，能够实现插入功能。
拓展;
- 实现按学号查找学生信息功能
- 实现清空数据功能
- 实现保存数据功能
- 实现右键菜单功能
解题思路/算法分析/问题及解决
本次实验可主要分为两个部分，即数据库连接操作部分和数据可视化操作界面部分。
数据库连接部分采用python的pymysql库对数据库进行连接操作。
数据可视化部分采用tableWidget控件进行表格化的呈现，并通过相应的控件交互来实现功能。TableWidget的主要方法如下表所示：
实验代码
数据库连接
def db_connect(self):
self.db = pymysql.connect(host='localhost',
user='root',
password='Zwq197166',
port=3306,
database='test')
可视化界面操作部分
def inser_row(self, row, sid, name, sex, address):
sid_item = QTableWidgetItem(sid)
name_item = QTableWidgetItem(name)
sex_item = QTableWidgetItem(sex)
address_item = QTableWidgetItem(address)
self.tableWidget.insertRow(row)
self.tableWidget.setItem(row, 0, sid_item)
self.tableWidget.setItem(row, 1, name_item)
self.tableWidget.setItem(row, 2, sex_item)
self.tableWidget.setItem(row, 3, address_item)
@pyqtSlot()
def on_button_load_clicked(self):
if self.button_save.isEnabled():
r = QMessageBox.warning(self, "警告", "是否覆盖当前表格数据", QMessageBox.Yes | QMessageBox.No, QMessageBox.Yes)
if r == QMessageBox.No:
return
self.tableWidget.setRowCount(0)
self.tableWidget.clearContents()
self.db_connect()
cursor = self.db.cursor()
sql = "select * from my_student;"
try:
cursor.execute(sql)
results = cursor.fetchall()
for (sid, name, sex,address) in results:
print(sid, name, sex, address)
row = self.tableWidget.rowCount()
# print(row)
self.inser_row(row, sid, name, sex, address)
data[sid] = [name, sex, address]
except:
print("unable to fetch data")
self.db.close()
self.button_save.setEnabled(True)
print("load")
@pyqtSlot()
def on_button_add_clicked(self):
di = inputDialog()
ok = di.exec_()
if not ok:
return
name = di.line_name.text()
sid = di.line_id.text()
sex = di.line_sex.text()
address = di.line_address.text()
print(name,sid)
print(type(address))
data[sid] = [name, sex, address]
self.inser_row(self.tableWidget.rowCount(), sid, name, sex, address)
print(data)
print("add")
# self.tableWidget.insertRow(self.tableWidget.rowCount()-1)
self.button_save.setEnabled(True)
@pyqtSlot()
def on_button_save_clicked(self):
print(data)
self.db_connect()
cursor = self.db.cursor()
try:
sql = "delete from my_student;"
cursor.execute(sql)
# self.db.commit()
for key, value in data.items():
sql = "insert into my_student(sid,name,sex,address) values('{sid}','{name}','{sex}','{address}');".format(sid=key, name=value[0], sex=value[1], address=value[2])
print(sql)
cursor.execute(sql)
self.db.commit()
self.db.close()
print("save")
self.button_save.setEnabled(False)
except:
QMessageBox.critical(self, "错误", "数据格式有误，请检查")
@pyqtSlot()
def on_button_clear_clicked(self):
self.tableWidget.setRowCount(0)
self.tableWidget.clearContents()
data.clear()
self.line_id.clear()
self.button_save.setEnabled(True)
@pyqtSlot()
def on_button_search_clicked(self):
sid = self.line_id.text()
if not sid:
QMessageBox.critical(self, "警告", "请输入一个学号！")
return
print(sid)
if sid in data:
search = INFO(sid)
search.exec_()
# print("search")
else:
QMessageBox.critical(self, "错误", "该学号不存在！")
@pyqtSlot(QTableWidgetItem)
def on_tableWidget_itemActivated(self, item):
"""
按住Enter键时，当前选中的单元格向下
"""
row = self.tableWidget.row(item)
column = self.tableWidget.column(item)
totalrow = self.tableWidget.rowCount()
if row + 1 < totalrow:
row = self.tableWidget.row(item) + 1
self.tableWidget.setCurrentCell(row, column)
elif row + 2 == totalrow:
row = totalrow - 1
self.tableWidget.setCurrentCell(row, column)
@pyqtSlot(int, int)
def on_tableWidget_cellDoubleClicked(self, row, column):
id = self.tableWidget.item(row, 0).text()
di = inputDialog(sid=id)
ok = di.exec_()
if not ok:
return
name = di.line_name.text()
sid = di.line_id.text()
sex = di.line_sex.text()
address = di.line_address.text()
print("before:", id)
print("after:", sid)
self.tableWidget.item(row, 0).setText(sid)
self.tableWidget.item(row, 1).setText(name)
self.tableWidget.item(row, 2).setText(sex)
self.tableWidget.item(row, 3).setText(address)
data[sid] = [name, sex, address]
if id != sid:
del data[id]
self.button_save.setEnabled(True)
def closeEvent(self, event):
if self.button_save.isEnabled():
r = QMessageBox.warning(self, "警告", "你还有操作没保存，现在保存下？", QMessageBox.Yes | QMessageBox.No, QMessageBox.Yes)
if r == QMessageBox.No:
event.accept()
else:
event.ignore()
def context_menu(self,pos):
pop_menu = QMenu()
change_new_event = pop_menu.addAction("修改行")
delete_event = pop_menu.addAction("删除行")
action = pop_menu.exec_(self.tableWidget.mapToGlobal(pos))
if action == change_new_event:
item = self.tableWidget.selectedItems()
row = item[0].row()
id = self.tableWidget.item(row, 0).text()
di = inputDialog(sid=id)
ok = di.exec_()
if not ok:
return
name = di.line_name.text()
sid = di.line_id.text()
sex = di.line_sex.text()
address = di.line_address.text()
print("before:",id)
print("after:",sid)
self.tableWidget.item(row, 0).setText(sid)
self.tableWidget.item(row, 1).setText(name)
self.tableWidget.item(row, 2).setText(sex)
self.tableWidget.item(row, 3).setText(address)
data[sid] = [name, sex, address]
if id != sid:
del data[id]
self.button_save.setEnabled(True)
elif action == delete_event:
r = QMessageBox.warning(self, "注意", "删除可不能恢复了哦！", QMessageBox.Yes | QMessageBox.No, QMessageBox.No)
if r == QMessageBox.No:
return
items = self.tableWidget.selectedItems()
if items:
selected_rows = []
for i in items:
row = i.row()
if row not in selected_rows:
selected_rows.append(row)
selected_rows = sorted(selected_rows, reverse=True)
for r in selected_rows:
sid = self.tableWidget.item(r, 0).text()
del data[sid]
self.tableWidget.removeRow(r)
self.button_save.setEnabled(True)
class inputDialog(QDialog, Ui_Dialog_input):
def __init__(self, sid=None):
super(inputDialog, self).__init__()
self.setupUi(self)
self.sid = sid
self.buttonBox.accepted.connect(self.check)
if sid:
self.line_id.setText(sid)
self.line_name.setText(data[sid][0])
self.line_sex.setText(data[sid][1])
self.line_address.setText(data[sid][2])
def check(self):
sid = self.line_id.text()
name = self.line_name.text()
if sid in data and self.sid not in data:
r = QMessageBox.warning(self, "警告", "该学号已存在!", QMessageBox.Ok)
return
if not sid:
r = QMessageBox.warning(self, "警告", "学号为必填项!", QMessageBox.Ok)
return
if not name:
r = QMessageBox.warning(self, "警告", "姓名为必填项!", QMessageBox.Ok)
return
self.accept()
# print('miss')
class INFO(QDialog, Ui_Dialog_info):
def __init__(self, id: str):
super(INFO, self).__init__()
self.setupUi(self)
self.line_id.setText(id)
self.line_name.setText(data[id][0])
self.line_sex.setText(data[id][1])
self.line_address.setText(data[id][2])
@pyqtSlot()
def on_button_confirm_clicked(self):
# print(1)
self.close()
运行结果
导入数据：
添加数据：
清空数据：
搜索数据：
修改数据：
双击修改
右键菜单修改：
删除后：
保存数据：
