درس ۸ مقدماتی: پایگاه داده مقدماتی با SQLite در پایتون

import sqlite3
conn = sqlite3.connect("mydb.db")
print("پایگاه داده ساخته شد!")
conn.close()

import sqlite3
conn = sqlite3.connect("school.db")
cursor = conn.cursor()
cursor.execute("CREATE TABLE IF NOT EXISTS students (id INTEGER PRIMARY KEY, name TEXT, grade REAL)")
conn.commit()
conn.close()

conn = sqlite3.connect("school.db")
cursor = conn.cursor()
cursor.execute("INSERT INTO students (name, grade) VALUES (?, ?)", ("علی", 15.5))
conn.commit()
conn.close()

conn = sqlite3.connect("school.db")
cursor = conn.cursor()
cursor.execute("SELECT * FROM students")
rows = cursor.fetchall()
for row in rows:
    print(f"ID: {row[0]}, نام: {row[1]}, نمره: {row[2]}")
conn.close()

conn = sqlite3.connect("school.db")
cursor = conn.cursor()
cursor.execute("UPDATE students SET grade = ? WHERE name = ?", (18.0, "علی"))
conn.commit()
conn.close()

conn = sqlite3.connect("school.db")
cursor = conn.cursor()
cursor.execute("DELETE FROM students WHERE grade < ?", (10.0,))
conn.commit()
conn.close()

try:
    conn = sqlite3.connect("school.db")
    cursor = conn.cursor()
    cursor.execute("SELECT * FROM nonexistent")
except sqlite3.OperationalError:
    print("جدول وجود نداره!")
finally:
    conn.close()

class StudentDB:
    def __init__(self, db_name):
        self.conn = sqlite3.connect(db_name)
        self.cursor = self.conn.cursor()
        self.cursor.execute("CREATE TABLE IF NOT EXISTS students (name TEXT, grade REAL)")

    def add_student(self, name, grade):
        self.cursor.execute("INSERT INTO students (name, grade) VALUES (?, ?)", (name, grade))
        self.conn.commit()

    def __del__(self):
        self.conn.close()

db = StudentDB("school.db")
db.add_student("مریم", 17.5)

import sqlite3
conn = sqlite3.connect("shop.db")
cursor = conn.cursor()
cursor.execute("CREATE TABLE IF NOT EXISTS items (id INTEGER PRIMARY KEY, item TEXT)")
cursor.execute("INSERT INTO items (item) VALUES (?)", ("شیر",))
conn.commit()
cursor.execute("SELECT * FROM items")
print(cursor.fetchall())
conn.close()

class GradeDB:
    def __init__(self):
        self.conn = sqlite3.connect("grades.db")
        self.cursor = self.conn.cursor()
        self.cursor.execute("CREATE TABLE IF NOT EXISTS grades (student TEXT, score REAL)")

    def add_grade(self, student, score):
        self.cursor.execute("INSERT INTO grades (student, score) VALUES (?, ?)", (student, score))
        self.conn.commit()

db = GradeDB()
db.add_grade("رضا", 19.0)

conn = sqlite3.connect("school.db")
cursor = conn.cursor()
name = input("نام دانش‌آموز: ")
cursor.execute("SELECT * FROM students WHERE name = ?", (name,))
result = cursor.fetchone()
if result:
    print(f"نام: {result[1]}, نمره: {result[2]}")
else:
    print("دانش‌آموز پیدا نشد!")
conn.close()

try:
    conn = sqlite3.connect("school.db")
    cursor = conn.cursor()
    cursor.execute("SELECT * FROM nonexistent")
except sqlite3.OperationalError:
    print("جدول وجود نداره!")
finally:
    conn.close()

import sqlite3

class SchoolManager:
    def __init__(self, db_name):
        self.conn = sqlite3.connect(db_name)
        self.cursor = self.conn.cursor()
        self.cursor.execute("CREATE TABLE IF NOT EXISTS students (id INTEGER PRIMARY KEY, name TEXT, grade REAL)")

    def add_student(self, name, grade):
        try:
            self.cursor.execute("INSERT INTO students (name, grade) VALUES (?, ?)", (name, grade))
            self.conn.commit()
            print(f"{name} اضافه شد!")
        except sqlite3.Error:
            print("خطا در افزودن!")

    def show_students(self):
        self.cursor.execute("SELECT * FROM students")
        rows = self.cursor.fetchall()
        if not rows:
            print("هیچ دانش‌آموزی نیست!")
        else:
            for row in rows:
                print(f"ID: {row[0]}, نام: {row[1]}, نمره: {row[2]}")

    def __del__(self):
        self.conn.close()

school = SchoolManager("school.db")
while True:
    print("\n=== مدیریت دانش‌آموزان ===")
    action = input("اضافه (a)، نمایش (s)، خروج (q): ")
    if action == "q":
        break
    elif action == "a":
        name = input("نام: ")
        grade = float(input("نمره: "))
        school.add_student(name, grade)
    elif action == "s":
        school.show_students()
print("خداحافظ!")