python3+PyQt5使用数据库表视图
这篇文章主要为大家详细介绍了python3+PyQt5使用数据库表视图,具有一定的参考价值,感兴趣的小伙伴们可以参考一下
上文提到窗体可以一次性呈现出来自同一记录的各个域,但是对于用户希望能看到多条记录的表来说,就需要使用表格化的视图了。本文通过python3+pyqt5改写实现了python Qt gui 快速变成15章的例子,用户能够一次看到多条记录。
#!/usr/bin/env python3 import os import sys from PyQt5.QtCore import (PYQT_VERSION_STR, QDate, QFile, QRegExp, QVariant, QModelIndex,Qt) from PyQt5.QtWidgets import (QApplication,QComboBox, QDateTimeEdit, QDialog, QGridLayout, QHBoxLayout, QLabel, QLineEdit, QDateEdit,QMessageBox, QPushButton, QStyleOptionViewItem, QTableView,QVBoxLayout) from PyQt5.QtGui import QPixmap,QCursor,QRegExpValidator from PyQt5.QtSql import (QSqlDatabase, QSqlQuery, QSqlRelation, QSqlRelationalDelegate, QSqlRelationalTableModel,QSqlTableModel) import qrc_resources MAC = True try: from PyQt5.QtGui import qt_mac_set_native_menubar except ImportError: MAC = False ID = 0 NAME = ASSETID = 1 CATEGORYID = DATE = DESCRIPTION = 2 ROOM = ACTIONID = 3 ACQUIRED = 1 def createFakeData(): import random print("Dropping tables...") query = QSqlQuery() query.exec_("DROP TABLE assets") query.exec_("DROP TABLE logs") query.exec_("DROP TABLE actions") query.exec_("DROP TABLE categories") QApplication.processEvents() print("Creating tables...") query.exec_("""CREATE TABLE actions ( id INTEGER PRIMARY KEY AUTOINCREMENT UNIQUE NOT NULL, name VARCHAR(20) NOT NULL, description VARCHAR(40) NOT NULL)""") query.exec_("""CREATE TABLE categories ( id INTEGER PRIMARY KEY AUTOINCREMENT UNIQUE NOT NULL, name VARCHAR(20) NOT NULL, description VARCHAR(40) NOT NULL)""") query.exec_("""CREATE TABLE assets ( id INTEGER PRIMARY KEY AUTOINCREMENT UNIQUE NOT NULL, name VARCHAR(40) NOT NULL, categoryid INTEGER NOT NULL, room VARCHAR(4) NOT NULL, FOREIGN KEY (categoryid) REFERENCES categories)""") query.exec_("""CREATE TABLE logs ( id INTEGER PRIMARY KEY AUTOINCREMENT UNIQUE NOT NULL, assetid INTEGER NOT NULL, date DATE NOT NULL, actionid INTEGER NOT NULL, FOREIGN KEY (assetid) REFERENCES assets, FOREIGN KEY (actionid) REFERENCES actions)""") QApplication.processEvents() print("Populating tables...") query.exec_("INSERT INTO actions (name, description) " "VALUES ('Acquired', 'When installed')") query.exec_("INSERT INTO actions (name, description) " "VALUES ('Broken', 'When failed and unusable')") query.exec_("INSERT INTO actions (name, description) " "VALUES ('Repaired', 'When back in service')") query.exec_("INSERT INTO actions (name, description) " "VALUES ('Routine maintenance', " "'When tested, refilled, etc.')") query.exec_("INSERT INTO categories (name, description) VALUES " "('Computer Equipment', " "'Monitors, System Units, Peripherals, etc.')") query.exec_("INSERT INTO categories (name, description) VALUES " "('Furniture', 'Chairs, Tables, Desks, etc.')") query.exec_("INSERT INTO categories (name, description) VALUES " "('Electrical Equipment', 'Non-computer electricals')") today = QDate.currentDate() floors = list(range(1, 12)) + list(range(14, 28)) monitors = (('17" LCD Monitor', 1), ('20" LCD Monitor', 1), ('21" LCD Monitor', 1), ('21" CRT Monitor', 1), ('24" CRT Monitor', 1)) computers = (("Computer (32-bit/80GB/0.5GB)", 1), ("Computer (32-bit/100GB/1GB)", 1), ("Computer (32-bit/120GB/1GB)", 1), ("Computer (64-bit/240GB/2GB)", 1), ("Computer (64-bit/320GB/4GB)", 1)) printers = (("Laser Printer (4 ppm)", 1), ("Laser Printer (6 ppm)", 1), ("Laser Printer (8 ppm)", 1), ("Laser Printer (16 ppm)", 1)) chairs = (("Secretary Chair", 2), ("Executive Chair (Basic)", 2), ("Executive Chair (Ergonimic)", 2), ("Executive Chair (Hi-Tech)", 2)) desks = (("Desk (Basic, 3 drawer)", 2), ("Desk (Standard, 3 drawer)", 2), ("Desk (Executive, 3 drawer)", 2), ("Desk (Executive, 4 drawer)", 2), ("Desk (Large, 4 drawer)", 2)) furniture = (("Filing Cabinet (3 drawer)", 2), ("Filing Cabinet (4 drawer)", 2), ("Filing Cabinet (5 drawer)", 2), ("Bookcase (4 shelves)", 2), ("Bookcase (6 shelves)", 2), ("Table (4 seater)", 2), ("Table (8 seater)", 2), ("Table (12 seater)", 2)) electrical = (("Fan (3 speed)", 3), ("Fan (5 speed)", 3), ("Photocopier (4 ppm)", 3), ("Photocopier (6 ppm)", 3), ("Photocopier (8 ppm)", 3), ("Shredder", 3)) query.prepare("INSERT INTO assets (name, categoryid, room) " "VALUES (:name, :categoryid, :room)") logQuery = QSqlQuery() logQuery.prepare("INSERT INTO logs (assetid, date, actionid) " "VALUES (:assetid, :date, :actionid)") assetid = 1 for i in range(20): room = "{0:02d}{1:02d}".format( random.choice(floors), random.randint(1, 62)) for name, category in (random.choice(monitors), random.choice(computers), random.choice(chairs), random.choice(desks), random.choice(furniture)): query.bindValue(":name", name) query.bindValue(":categoryid", category) query.bindValue(":room", room) query.exec_() logQuery.bindValue(":assetid", assetid) when = today.addDays(-random.randint(7, 1500)) #when=when.toString() logQuery.bindValue(":date", when.toString("yyyy-MM-dd")) logQuery.bindValue(":actionid", ACQUIRED) logQuery.exec_() if random.random() > 0.7: logQuery.bindValue(":assetid", assetid) when = when.addDays(random.randint(1, 1500)) if when <= today: logQuery.bindValue(":date", when.toString("yyyy-MM-dd")) logQuery.bindValue(":actionid", random.choice((2, 4))) logQuery.exec_() assetid += 1 if random.random() > 0.8: name, category = random.choice(printers) query.bindValue(":name", name) query.bindValue(":categoryid", category) query.bindValue(":room", room) query.exec_() logQuery.bindValue(":assetid", assetid) when = today.addDays(-random.randint(7, 1500)) logQuery.bindValue(":date", when.toString("yyyy-MM-dd")) logQuery.bindValue(":actionid",ACQUIRED) logQuery.exec_() if random.random() > 0.6: logQuery.bindValue(":assetid", assetid) when = when.addDays(random.randint(1, 1500)) if when <= today: logQuery.bindValue(":date", when.toString("yyyy-MM-dd")) logQuery.bindValue(":actionid", random.choice((2, 4))) logQuery.exec_() assetid += 1 if random.random() > 0.6: name, category = random.choice(electrical) query.bindValue(":name", name) query.bindValue(":categoryid", category) query.bindValue(":room", room) query.exec_() logQuery.bindValue(":assetid", assetid) when = today.addDays(-random.randint(7, 1500)) logQuery.bindValue(":date", when.toString("yyyy-MM-dd")) logQuery.bindValue(":actionid",ACQUIRED) logQuery.exec_() if random.random() > 0.5: logQuery.bindValue(":assetid", assetid) when = when.addDays(random.randint(1, 1500)) if when <= today: logQuery.bindValue(":date", when.toString("yyyy-MM-dd")) logQuery.bindValue(":actionid", random.choice((2, 4))) logQuery.exec_() assetid += 1 QApplication.processEvents() print("Assets:") query.exec_("SELECT id, name, categoryid, room FROM assets " "ORDER by id") categoryQuery = QSqlQuery() while query.next(): id = query.value(0) name = str(query.value(1)) categoryid = query.value(2) room = str(query.value(3)) categoryQuery.exec_("SELECT name FROM categories " "WHERE id = {0}".format(categoryid)) category = "{0}".format(categoryid) if categoryQuery.next(): category = str(categoryQuery.value(0)) print("{0}: {1} [{2}] {3}".format(id, name, category, room)) QApplication.processEvents() class ReferenceDataDlg(QDialog): def __init__(self, table, title, parent=None): super(ReferenceDataDlg, self).__init__(parent) self.model = QSqlTableModel(self) self.model.setTable(table) self.model.setSort(NAME, Qt.AscendingOrder) self.model.setHeaderData(ID, Qt.Horizontal,"ID") self.model.setHeaderData(NAME, Qt.Horizontal, "Name") self.model.setHeaderData(DESCRIPTION, Qt.Horizontal,"Description") self.model.select() self.view = QTableView() self.view.setModel(self.model) self.view.setSelectionMode(QTableView.SingleSelection) self.view.setSelectionBehavior(QTableView.SelectRows) self.view.setColumnHidden(ID, True) self.view.resizeColumnsToContents() addButton = QPushButton("&Add") deleteButton = QPushButton("&Delete") okButton = QPushButton("&OK") if not MAC: addButton.setFocusPolicy(Qt.NoFocus) deleteButton.setFocusPolicy(Qt.NoFocus) buttonLayout = QHBoxLayout() buttonLayout.addWidget(addButton) buttonLayout.addWidget(deleteButton) buttonLayout.addStretch() buttonLayout.addWidget(okButton) layout = QVBoxLayout() layout.addWidget(self.view) layout.addLayout(buttonLayout) self.setLayout(layout) addButton.clicked.connect(self.addRecord) deleteButton.clicked.connect(self.deleteRecord) okButton.clicked.connect(self.accept) self.setWindowTitle( "Asset Manager - Edit {0} Reference Data".format(title)) def addRecord(self): row = self.model.rowCount() self.model.insertRow(row) index = self.model.index(row, NAME) self.view.setCurrentIndex(index) self.view.edit(index) def deleteRecord(self): index = self.view.currentIndex() if not index.isValid(): return #QSqlDatabase.database().transaction() record = self.model.record(index.row()) id = record.value(ID) table = self.model.tableName() query = QSqlQuery() if table == "actions": query.exec_("SELECT COUNT(*) FROM logs " "WHERE actionid = {0}".format(id)) elif table == "categories": query.exec_("SELECT COUNT(*) FROM assets " "WHERE categoryid = {0}".format(id)) count = 0 if query.next(): count = query.value(0) if count: QMessageBox.information(self, "Delete {0}".format(table), ("Cannot delete {0}<br>" "from the {1} table because it is used by " "{2} records").format(record.value(NAME),table,count)) #QSqlDatabase.database().rollback() return self.model.removeRow(index.row()) self.model.submitAll() self.model.select() #QSqlDatabase.database().commit() class AssetDelegate(QSqlRelationalDelegate): def __init__(self, parent=None): super(AssetDelegate, self).__init__(parent) def paint(self, painter, option, index): myoption = QStyleOptionViewItem(option) if index.column() == ROOM: myoption.displayAlignment |= (Qt.AlignRight|Qt.AlignVCenter) QSqlRelationalDelegate.paint(self, painter, myoption, index) def createEditor(self, parent, option, index): if index.column() == ROOM: editor = QLineEdit(parent) regex = QRegExp(r"(?:0[1-9]|1[0124-9]|2[0-7])" r"(?:0[1-9]|[1-5][0-9]|6[012])") validator = QRegExpValidator(regex, parent) editor.setValidator(validator) editor.setInputMask("9999") editor.setAlignment(Qt.AlignRight|Qt.AlignVCenter) return editor else: return QSqlRelationalDelegate.createEditor(self, parent, option, index) def setEditorData(self, editor, index): if index.column() == ROOM: text = index.model().data(index, Qt.DisplayRole) editor.setText(text) else: QSqlRelationalDelegate.setEditorData(self, editor, index) def setModelData(self, editor, model, index): if index.column() == ROOM: model.setData(index, editor.text()) else: QSqlRelationalDelegate.setModelData(self, editor, model, index) class LogDelegate(QSqlRelationalDelegate): def __init__(self, parent=None): super(LogDelegate, self).__init__(parent) def paint(self, painter, option, index): myoption = QStyleOptionViewItem(option) if index.column() == DATE: myoption.displayAlignment |= (Qt.AlignRight|Qt.AlignVCenter) QSqlRelationalDelegate.paint(self, painter, myoption, index) def createEditor(self, parent, option, index): if (index.column() == ACTIONID and index.model().data(index, Qt.DisplayRole) == ACQUIRED): # Acquired is read-only return if index.column() == DATE: editor = QDateEdit(parent) editor.setMaximumDate(QDate.currentDate()) editor.setDisplayFormat("yyyy-MM-dd") if PYQT_VERSION_STR >= "4.1.0": editor.setCalendarPopup(True) editor.setAlignment(Qt.AlignRight| Qt.AlignVCenter) return editor else: return QSqlRelationalDelegate.createEditor(self, parent, option, index) def setEditorData(self, editor, index): if index.column() == DATE: date = index.model().data(index, Qt.DisplayRole) editor.setDate(date) else: QSqlRelationalDelegate.setEditorData(self, editor, index) def setModelData(self, editor, model, index): if index.column() == DATE: model.setData(index, QVariant(editor.date())) else: QSqlRelationalDelegate.setModelData(self, editor, model, index) class MainForm(QDialog): def __init__(self): super(MainForm, self).__init__() self.assetModel = QSqlRelationalTableModel(self) self.assetModel.setTable("assets") self.assetModel.setRelation(CATEGORYID, QSqlRelation("categories", "id", "name")) self.assetModel.setSort(ROOM, Qt.AscendingOrder) self.assetModel.setHeaderData(ID, Qt.Horizontal,"ID") self.assetModel.setHeaderData(NAME, Qt.Horizontal,"Name") self.assetModel.setHeaderData(CATEGORYID, Qt.Horizontal,"Category") self.assetModel.setHeaderData(ROOM, Qt.Horizontal,"Room") self.assetModel.select() self.assetView = QTableView() self.assetView.setModel(self.assetModel) self.assetView.setItemDelegate(AssetDelegate(self)) self.assetView.setSelectionMode(QTableView.SingleSelection) self.assetView.setSelectionBehavior(QTableView.SelectRows) self.assetView.setColumnHidden(ID, True) self.assetView.resizeColumnsToContents() assetLabel = QLabel("A&ssets") assetLabel.setBuddy(self.assetView) self.logModel = QSqlRelationalTableModel(self) self.logModel.setTable("logs") self.logModel.setRelation(ACTIONID, QSqlRelation("actions", "id", "name")) self.logModel.setSort(DATE, Qt.AscendingOrder) self.logModel.setHeaderData(DATE, Qt.Horizontal, "Date") self.logModel.setHeaderData(ACTIONID, Qt.Horizontal,"Action") self.logModel.select() self.logView = QTableView() self.logView.setModel(self.logModel) self.logView.setItemDelegate(LogDelegate(self)) self.logView.setSelectionMode(QTableView.SingleSelection) self.logView.setSelectionBehavior(QTableView.SelectRows) self.logView.setColumnHidden(ID, True) self.logView.setColumnHidden(ASSETID, True) self.logView.resizeColumnsToContents() self.logView.horizontalHeader().setStretchLastSection(True) logLabel = QLabel("&Logs") logLabel.setBuddy(self.logView) addAssetButton = QPushButton("&Add Asset") deleteAssetButton = QPushButton("&Delete Asset") addActionButton = QPushButton("Add A&ction") deleteActionButton = QPushButton("Delete Ac&tion") editActionsButton = QPushButton("&Edit Actions...") editCategoriesButton = QPushButton("Ed&it Categories...") quitButton = QPushButton("&Quit") for button in (addAssetButton, deleteAssetButton, addActionButton, deleteActionButton, editActionsButton, editCategoriesButton, quitButton): if MAC: button.setDefault(False) button.setAutoDefault(False) else: button.setFocusPolicy(Qt.NoFocus) dataLayout = QVBoxLayout() dataLayout.addWidget(assetLabel) dataLayout.addWidget(self.assetView, 1) dataLayout.addWidget(logLabel) dataLayout.addWidget(self.logView) buttonLayout = QVBoxLayout() buttonLayout.addWidget(addAssetButton) buttonLayout.addWidget(deleteAssetButton) buttonLayout.addWidget(addActionButton) buttonLayout.addWidget(deleteActionButton) buttonLayout.addWidget(editActionsButton) buttonLayout.addWidget(editCategoriesButton) buttonLayout.addStretch() buttonLayout.addWidget(quitButton) layout = QHBoxLayout() layout.addLayout(dataLayout, 1) layout.addLayout(buttonLayout) self.setLayout(layout) #self.connect(self.assetView.selectionModel(), #SIGNAL(("currentRowChanged(QModelIndex,QModelIndex)")), #self.assetChanged) self.assetView.selectionModel().currentRowChanged.connect(self.assetChanged) addAssetButton.clicked.connect(self.addAsset) deleteAssetButton.clicked.connect(self.deleteAsset) addActionButton.clicked.connect(self.addAction) deleteActionButton.clicked.connect(self.deleteAction) editActionsButton.clicked.connect(self.editActions) editCategoriesButton.clicked.connect(self.editCategories) quitButton.clicked.connect(self.done) self.assetChanged(self.assetView.currentIndex()) self.setMinimumWidth(650) self.setWindowTitle("Asset Manager") def done(self, result=1): query = QSqlQuery() query.exec_("DELETE FROM logs WHERE logs.assetid NOT IN" "(SELECT id FROM assets)") QDialog.done(self, 1) def assetChanged(self, index): if index.isValid(): record = self.assetModel.record(index.row()) #print(index.row()) id = record.value("id") self.logModel.setFilter("assetid = {0}".format(id)) else: self.logModel.setFilter("assetid = -1") #self.logModel.reset() # workaround for Qt <= 4.3.3/SQLite bug #self.logModel.beginResetModel() self.logModel.select() self.logView.horizontalHeader().setVisible( self.logModel.rowCount() > 0) if PYQT_VERSION_STR < "4.1.0": self.logView.setColumnHidden(ID, True) self.logView.setColumnHidden(ASSETID, True) #self.logModel.endResetModel() def addAsset(self): row = (self.assetView.currentIndex().row() if self.assetView.currentIndex().isValid() else 0) QSqlDatabase.database().transaction() self.assetModel.insertRow(row) index = self.assetModel.index(row, NAME) self.assetView.setCurrentIndex(index) assetid = 1 query = QSqlQuery() query.exec_("SELECT MAX(id) FROM assets") if query.next(): assetid = query.value(0) query.prepare("INSERT INTO logs (assetid, date, actionid) " "VALUES (:assetid, :date, :actionid)") query.bindValue(":assetid", assetid + 1) query.bindValue(":date", QDate.currentDate()) query.bindValue(":actionid", ACQUIRED) query.exec_() QSqlDatabase.database().commit() #self.logModel.select() self.assetView.edit(index) def deleteAsset(self): index = self.assetView.currentIndex() if not index.isValid(): return QSqlDatabase.database().transaction() record = self.assetModel.record(index.row()) assetid = record.value(ID) logrecords = 1 query = QSqlQuery("SELECT COUNT(*) FROM logs WHERE assetid = {0}".format(assetid)) if query.next(): logrecords = query.value(0) msg = ("<font color=red>Delete</font><br><b>{0}</b>" "<br>from room {1}").format(record.value(NAME),record.value(ROOM)) if logrecords > 1: msg += (", along with {0} log records" .format(logrecords)) msg += "?" if (QMessageBox.question(self, "Delete Asset", msg, QMessageBox.Yes|QMessageBox.No) == QMessageBox.No): QSqlDatabase.database().rollback() return #query.exec_("DELETE FROM logs WHERE assetid = {0}" # .format(assetid)) #use model API self.logModel.setFilter("assetid={0}".format(assetid)) self.logModel.select() if self.logModel.rowCount()>0: self.logModel.removeRows(0,self.logModel.rowCount()) self.logModel.submitAll() self.assetModel.removeRow(index.row()) self.assetModel.submitAll() QSqlDatabase.database().commit() self.assetModel.select() self.assetChanged(self.assetView.currentIndex()) def addAction(self): index = self.assetView.currentIndex() if not index.isValid(): return QSqlDatabase.database().transaction() record = self.assetModel.record(index.row()) assetid = record.value(ID) row = self.logModel.rowCount() self.logModel.insertRow(row) self.logModel.setData(self.logModel.index(row, ASSETID), assetid) self.logModel.setData(self.logModel.index(row, DATE), QDate.currentDate()) QSqlDatabase.database().commit() index = self.logModel.index(row, ACTIONID) self.logView.setCurrentIndex(index) self.logView.edit(index) def deleteAction(self): index = self.logView.currentIndex() if not index.isValid(): return record = self.logModel.record(index.row()) action = record.value(ACTIONID) if action == "Acquired": QMessageBox.information(self, "Delete Log", "The 'Acquired' log record cannot be deleted.<br>" "You could delete the entire asset instead.") return when = str(record.value(DATE)) if (QMessageBox.question(self, "Delete Log", "Delete log<br>{0} {1}?".format(when, action), QMessageBox.Yes|QMessageBox.No) == QMessageBox.No): return self.logModel.removeRow(index.row()) self.logModel.submitAll() self.logModel.select() def editActions(self): form = ReferenceDataDlg("actions", "Action", self) form.exec_() def editCategories(self): form = ReferenceDataDlg("categories", "Category", self) form.exec_() def main(): app = QApplication(sys.argv) filename = os.path.join(os.path.dirname(__file__), "assets.db") create = not QFile.exists(filename) db = QSqlDatabase.addDatabase("QSQLITE") db.setDatabaseName(filename) if not db.open(): QMessageBox.warning(None, "Asset Manager", ("Database Error: {0}" .format(db.lastError().text()))) sys.exit(1) splash = None if create: app.setOverrideCursor(QCursor(Qt.WaitCursor)) splash = QLabel() pixmap = QPixmap(":/assetmanagersplash.png") splash.setPixmap(pixmap) splash.setMask(pixmap.createHeuristicMask()) splash.setWindowFlags(Qt.SplashScreen) rect = app.desktop().availableGeometry() splash.move((rect.width() - pixmap.width()) / 2, (rect.height() - pixmap.height()) / 2) splash.show() app.processEvents() createFakeData() form = MainForm() form.show() if create: splash.close() app.processEvents() app.restoreOverrideCursor() app.exec_() del form del db main()
运行结果:
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Untuk mengendalikan ralat sambungan pangkalan data dalam PHP, anda boleh menggunakan langkah berikut: Gunakan mysqli_connect_errno() untuk mendapatkan kod ralat. Gunakan mysqli_connect_error() untuk mendapatkan mesej ralat. Dengan menangkap dan mengelog mesej ralat ini, isu sambungan pangkalan data boleh dikenal pasti dan diselesaikan dengan mudah, memastikan kelancaran aplikasi anda.

PHP ialah bahasa pengaturcaraan bahagian belakang yang digunakan secara meluas dalam pembangunan laman web Ia mempunyai fungsi operasi pangkalan data yang kuat dan sering digunakan untuk berinteraksi dengan pangkalan data seperti MySQL. Walau bagaimanapun, disebabkan kerumitan pengekodan aksara Cina, masalah sering timbul apabila berurusan dengan aksara Cina bercelaru dalam pangkalan data. Artikel ini akan memperkenalkan kemahiran dan amalan PHP dalam mengendalikan aksara bercelaru bahasa Cina dalam pangkalan data, termasuk punca biasa aksara bercelaru, penyelesaian dan contoh kod khusus. Sebab biasa aksara bercelaru ialah tetapan set aksara pangkalan data yang salah: set aksara yang betul perlu dipilih semasa mencipta pangkalan data, seperti utf8 atau u

Menggunakan fungsi panggil balik pangkalan data di Golang boleh mencapai: melaksanakan kod tersuai selepas operasi pangkalan data yang ditentukan selesai. Tambah tingkah laku tersuai melalui fungsi berasingan tanpa menulis kod tambahan. Fungsi panggil balik tersedia untuk operasi memasukkan, mengemas kini, memadam dan pertanyaan. Anda mesti menggunakan fungsi sql.Exec, sql.QueryRow atau sql.Query untuk menggunakan fungsi panggil balik.
