initial commit

.gitignore

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+.venv
+.idea

main.py

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+import psycopg2
+from psycopg2 import sql
+from psycopg2.errors import DuplicateDatabase
+from PyQt5.QtWidgets import QApplication, QMainWindow, QGridLayout, QWidget, QTableWidget, QTableWidgetItem, QHeaderView
+from PyQt5.QtCore import QSize, Qt
+
+
+def connect(config):
+    """ Connect to the PostgreSQL database server """
+    try:
+        # connecting to the PostgreSQL server
+        with psycopg2.connect(**config) as conn:
+            print('Connected to the PostgreSQL server.')
+            return conn
+    except (psycopg2.DatabaseError, Exception) as error:
+        print(error)
+
+
+def createUsersDB(config):
+    """ Connect to the PostgreSQL database server """
+    try:
+        # connecting to the PostgreSQL server
+        conn.autocommit = True
+        cur = conn.cursor()
+        cur.execute(sql.SQL("CREATE DATABASE {}").format(
+            sql.Identifier('university'))
+        )
+        print('db created')
+    except DuplicateDatabase:
+            print('db already exists')
+            pass
+
+
+def createuUiversityDB(config):
+    """ Connect to the PostgreSQL database server """
+    try:
+        # connecting to the PostgreSQL server
+        conn.autocommit = True
+        cur = conn.cursor()
+        cur.execute(sql.SQL("CREATE DATABASE {}").format(
+            sql.Identifier('university'))
+        )
+        print('db created')
+    except DuplicateDatabase:
+            print('db already exists')
+            pass
+
+
+def createUsersTable(config):
+    """ Connect to the PostgreSQL database server """
+    try:
+        # connecting to the PostgreSQL server
+        conn.autocommit = True
+        cur = conn.cursor()
+        cur.execute(sql.SQL("CREATE TABLE IF NOT EXISTS users(id int, name varchar(255), age int)"))
+        print('table created')
+    except (psycopg2.DatabaseError, Exception) as error:
+        print(error)
+
+
+def selectUsers(config):
+    try:
+        cur = conn.cursor()
+        cur.execute(sql.SQL("SELECT * FROM users"))
+        return cur.fetchall()
+    except (psycopg2.DatabaseError, Exception) as error:
+        print(error)
+        return []
+
+
+def insertUsersData(config, values):
+    """ Connect to the PostgreSQL database server """
+    try:
+        conn.autocommit = True
+        cur = conn.cursor()
+
+        users = selectUsers(conn)
+
+        if len(users) == 0:
+            args = ','.join(cur.mogrify("(%s,%s,%s)", i).decode('utf-8')
+                            for i in values)
+
+            # executing the sql statement
+            cur.execute("INSERT INTO users VALUES " + (args))
+            print('inserted')
+        else:
+            print('already inserted')
+            print(users)
+    except (psycopg2.DatabaseError, Exception) as error:
+        print(error)
+
+
+class MainWindow(QMainWindow):
+    # Override class constructor
+    def __init__(self):
+        # You must call the super class method
+        QMainWindow.__init__(self)
+
+        self.setMinimumSize(QSize(480, 80))  # Set sizes
+        self.setWindowTitle("DB example")  # Set the window title
+        central_widget = QWidget(self)  # Create a central widget
+        self.setCentralWidget(central_widget)  # Install the central widget
+
+        grid_layout = QGridLayout(self)  # Create QGridLayout
+        central_widget.setLayout(grid_layout)  # Set this layout in central widget
+
+        self.table = QTableWidget(self)  # Create a table
+        self.table.setColumnCount(3)  # Set three columns
+        self.table.setRowCount(1)  # and one row
+        self.table.horizontalHeader().setSectionResizeMode(1, QHeaderView.Stretch)
+        # Set the table headers
+        self.table.setHorizontalHeaderLabels(["ID", "Name", "Age"])
+
+        # Set the tooltips to headings
+        self.table.horizontalHeaderItem(0).setToolTip("ID ")
+        self.table.horizontalHeaderItem(1).setToolTip("Name ")
+        self.table.horizontalHeaderItem(2).setToolTip("Age ")
+
+        # Set the alignment to the headers
+        self.table.horizontalHeaderItem(0).setTextAlignment(Qt.AlignHCenter)
+        self.table.horizontalHeaderItem(1).setTextAlignment(Qt.AlignHCenter)
+        self.table.horizontalHeaderItem(2).setTextAlignment(Qt.AlignHCenter)
+
+        # Do the resize of the columns by content
+        self.table.resizeColumnsToContents()
+
+        grid_layout.addWidget(self.table, 0, 0)  # Adding the table to the grid
+
+    def load_data(self, users_data):
+        for i, user in enumerate(users_data):
+            row_number = self.table.rowCount()-1
+            if len(users_data) != self.table.rowCount():
+                self.table.insertRow(row_number)
+            self.table.setItem(row_number, 0, QTableWidgetItem(str(user[0])))
+            self.table.setItem(row_number, 1, QTableWidgetItem(str(user[1])))
+            self.table.setItem(row_number, 2, QTableWidgetItem(str(user[2])))
+
+
+if __name__ == "__main__":
+    import sys
+
+    conn = psycopg2.connect("user=postgres password=456")
+
+    createuUiversityDB(conn)
+    createUsersTable(conn)
+
+    values = [(1, 'Ivan', 15), (2, 'Igor', 22), (3, 'Alex', 16), (4, 'Anna', 40), (5, 'Inna', 30)]
+
+    insertUsersData(conn, values)
+
+    users = selectUsers(conn)
+
+    app = QApplication(sys.argv)
+    mw = MainWindow()
+    mw.load_data(users)
+    mw.show()
+    sys.exit(app.exec())