feat: Add $or logical operator for querying , Student Gradebook CLI

README.md

@@ -90,6 +90,7 @@ pip install -e .
 - String operations (`$contains`, `$startswith`, `$endswith`)
 - Regular expression matching
 - List membership testing (`$in`, `$nin`)
+- Logical Operators (`$or`)
 
 ### 🔧 **Developer Friendly**
 - Verbose mode for debugging

cafedb.py

@@ -113,19 +113,42 @@ def _match_condition(self, value: Any, condition: Union[Any, Dict[str, Any]]) ->
             else:
                 return value == condition
 
+
     def _build_condition_function(self, filters: Dict[str, Any]) -> Callable:
+        or_clause = filters.get('$or')
+        and_filters = {key: value for key, value in filters.items() if key != '$or'}
+
         def condition_func(row: dict) -> bool:
-            for field, condition in filters.items():
+            for field, condition in and_filters.items():
                 if field not in row:
                     return False
-
                 if not self._match_condition(row[field], condition):
                     return False
-
+
+            if or_clause:
+                if not isinstance(or_clause, list):
+                    raise ValueError("$or operator requires a list of conditions.")
+
+                or_match_found = False
+                for sub_filter in or_clause:
+                    sub_filter_passes = True
+                    for field, condition in sub_filter.items():
+                        if field not in row or not self._match_condition(row[field], condition):
+                            sub_filter_passes = False
+                            break 
+
+                    if sub_filter_passes:
+                        or_match_found = True
+                        break 
+
+                if not or_match_found:
+                    return False
+
             return True
 
         return condition_func
 
+
     def insert(self, table_name: str, row: dict):
         if table_name not in self._data:
             raise ValueError(f"Table '{table_name}' does not exist.")
@@ -307,11 +330,21 @@ def stats(self, table_name: str):
         {"age": {"$gte": 45}},
         {"category": "senior", "discount": 0.1}
     )
+    print("\n8. Users from London who are either young or high-scorers:")
+    results = db.select("users", {
+        "city": "London",
+        "$or": [
+        {"age": {"$lt": 30}},
+        {"score": {"$gte": 85}}
+    ]
+    })
+    for user in results:
+        print(f"   - {user['name']} (Age: {user['age']}, Score: {user['score']})")
 
     print("\n=== TABLE STATISTICS ===")
     stats = db.stats("users")
     print(f"Table: {stats['table']}")
     print(f"Total rows: {stats['total_rows']}")
     print("Fields:")
     for field, info in stats['fields'].items():
-        print(f"  {field}: {info['present_count']} present, {info['unique_count']} unique, types: {info['data_types']}")
+        print(f"  {field}: {info['present_count']} present, {info['unique_count']} unique, types: {info['data_types']}")

usage.py

@@ -1,84 +1,204 @@
 from cafedb import CafeDB
 from datetime import datetime
+import uuid
+import os
 
-# Initialize database
-db = CafeDB("user_management.cdb", verbose=True)
-db.create_table("users")
-db.create_table("sessions")
-
-# User registration
-def register_user(name, email, age, city):
-    # Check if user already exists
-    existing = db.select("users", {"email": email})
-    if existing:
-        raise ValueError("User with this email already exists")
-
-    user = {
+db = CafeDB("student_grades.cdb", verbose=False) 
+
+def clear_screen():
+    """Clears the terminal screen."""
+    os.system('cls' if os.name == 'nt' else 'clear')
+
+def print_header(title):
+    """Prints a formatted header."""
+    print("=" * 40)
+    print(f"| {title.center(36)} |")
+    print("=" * 40)
+
+def press_enter_to_continue():
+    """Pauses execution until the user presses Enter."""
+    input("\nPress Enter to continue...")
+
+def setup_database():
+    """Creates the necessary tables if they don't exist."""
+    try:
+        db.create_table("students")
+    except ValueError:
+        pass 
+
+    try:
+        db.create_table("grades")
+    except ValueError:
+        pass 
+
+def add_student_cli():
+    """CLI function to add a new student."""
+    print_header("Add New Student")
+    name = input("Enter student's full name: ")
+    email = input("Enter student's email: ")
+    while db.select("students", {"email": email}):
+        print("A student with this email already exists.")
+        email = input("Enter a different email: ")
+
+    try:
+        enrollment_year = int(input("Enter enrollment year: "))
+    except ValueError:
+        print("Invalid year. Please enter a number.")
+        return
+
+    student = {
+        "student_id": str(uuid.uuid4())[:8],
         "name": name,
         "email": email,
-        "age": age,
-        "city": city,
-        "created_at": datetime.now().isoformat(),
-        "active": True,
-        "login_count": 0
+        "enrollment_year": enrollment_year,
+        "created_at": datetime.now().isoformat()
     }
-
-    db.insert("users", user)
-    return user
-
-# User authentication simulation
-def login_user(email):
-    users = db.select("users", {"email": email, "active": True})
-    if not users:
-        raise ValueError("User not found or inactive")
-
-    user = users[0]
-
-    # Update login count
-    db.update("users", 
-        {"email": email},
-        lambda u: {**u, "login_count": u.get("login_count", 0) + 1, 
-                  "last_login": datetime.now().isoformat()}
-    )
-
-    # Create session
-    session = {
-        "email": email,
-        "login_time": datetime.now().isoformat(),
-        "active": True
-    }
-    db.insert("sessions", session)
-
-    return user
-
-# Analytics
-def get_user_analytics():
-    total_users = db.count("users")
-    active_users = db.count("users", {"active": True})
-    recent_users = db.count("users", {
-        "created_at": {"$gte": "2024-01-01T00:00:00Z"}
-    })
-
-    # Most common cities
-    all_users = db.select("users")
-    city_count = {}
-    for user in all_users:
-        city = user.get("city", "Unknown")
-        city_count[city] = city_count.get(city, 0) + 1
-
-    return {
-        "total_users": total_users,
-        "active_users": active_users,
-        "recent_users": recent_users,
-        "cities": dict(sorted(city_count.items(), key=lambda x: x[1], reverse=True))
+    db.insert("students", student)
+    print(f"\n Student '{name}' added successfully with ID: {student['student_id']}")
+
+def record_grade_cli():
+    """CLI function to record a new grade."""
+    print_header("Record a Grade")
+    student_id = input("Enter the student ID to record a grade for: ")
+    if not db.select("students", {"student_id": student_id}):
+        print(f" Error: Student with ID '{student_id}' not found.")
+        return
+
+    subject = input("Enter the subject (e.g., Math, Science): ")
+    try:
+        score = float(input("Enter the score: "))
+        if not 0 <= score <= 100:
+            raise ValueError("Score must be between 0 and 100.")
+    except ValueError as e:
+        print(f" Invalid score. {e}")
+        return
+
+    grade = {
+        "grade_id": str(uuid.uuid4())[:8],
+        "student_id": student_id,
+        "subject": subject,
+        "score": score,
+        "date": datetime.now().date().isoformat()
     }
+    db.insert("grades", grade)
+    print(f"\n Grade of {score} in {subject} recorded for student {student_id}.")
+
+def view_student_grades_cli():
+    """CLI function to view all grades for a specific student."""
+    print_header("View Student Grades")
+    student_id = input("Enter the student ID: ")
+    student = db.select("students", {"student_id": student_id})
+    if not student:
+        print(f" Error: Student with ID '{student_id}' not found.")
+        return
+
+    grades = db.select("grades", {"student_id": student_id})
+    print(f"\nGrades for {student[0]['name']} ({student_id}):")
+    if not grades:
+        print("No grades found for this student.")
+    else:
+        for grade in grades:
+            print(f"  - Subject: {grade['subject']}, Score: {grade['score']}, Date: {grade['date']}")
+
+def find_top_performers_cli():
+    """CLI function to find top performers in a subject."""
+    print_header("Find Top Performers")
+    subject = input("Enter the subject to search in: ")
+    try:
+        min_score = float(input("Enter the minimum score to be considered a top performer (e.g., 90): "))
+    except ValueError:
+        print(" Invalid score.")
+        return
+
+    results = db.select("grades", {"subject": subject, "score": {"$gte": min_score}})
+    print(f"\nTop Performers in {subject} (Score >= {min_score}):")
+    if not results:
+        print("No students met the criteria.")
+    else:
+        for grade in results:
+            student = db.select("students", {"student_id": grade['student_id']})
+            if student:
+                print(f"  - Student: {student[0]['name']}, Score: {grade['score']}")
+
+def list_all_students_cli():
+    """Lists all students in the database."""
+    print_header("All Students")
+    students = db.select("students")
+    if not students:
+        print("No students in the database.")
+    else:
+        for student in students:
+            print(f"  - Name: {student['name']}, Email: {student['email']}, ID: {student['student_id']}")
+
+def delete_student_cli():
+    """CLI function to delete a student."""
+    print_header("Delete a Student")
+    student_id = input("Enter the ID of the student to delete: ")
+    student = db.select("students", {"student_id": student_id})
+    if not student:
+        print(f" Error: Student with ID '{student_id}' not found.")
+        return
+
+    confirm = input(f"Are you sure you want to delete {student[0]['name']} and all their grades? (y/n): ").lower()
+    if confirm == 'y':
+        db.delete("students", {"student_id": student_id})
+        db.delete("grades", {"student_id": student_id})
+        print(f" Student {student_id} has been deleted.")
+    else:
+        print("Deletion cancelled.")
+
+def get_database_stats_cli():
+    """Displays statistics for all tables."""
+    print_header("Database Statistics")
+    for table_name in db.list_tables():
+        stats = db.stats(table_name)
+        print(f"\n--- Table: {stats['table']} ---")
+        print(f"  Total Rows: {stats['total_rows']}")
+        if "fields" in stats and stats['fields']:
+            print("  Fields:")
+            for field, info in stats['fields'].items():
+                print(f"    - {field}: Present: {info['present_count']}, Unique: {info['unique_count']}")
+        else:
+            print("  No fields or data in this table.")
+
+def main_menu():
+    """Displays the main menu and handles user input."""
+    while True:
+        clear_screen()
+        print_header("Student Gradebook CLI")
+        print("1. Add New Student")
+        print("2. Record a Grade")
+        print("3. View a Student's Grades")
+        print("4. Find Top Performers in a Subject")
+        print("5. List All Students")
+        print("6. Delete a Student")
+        print("7. View Database Statistics")
+        print("0. Exit")
+        print("-" * 40)
+        choice = input("Enter your choice: ")
 
-# Usage
-register_user("Alice Johnson", "alice@example.com", 28, "Paris")
-register_user("Bob Smith", "bob@example.com", 34, "London")
+        if choice == '1':
+            add_student_cli()
+        elif choice == '2':
+            record_grade_cli()
+        elif choice == '3':
+            view_student_grades_cli()
+        elif choice == '4':
+            find_top_performers_cli()
+        elif choice == '5':
+            list_all_students_cli()
+        elif choice == '6':
+            delete_student_cli()
+        elif choice == '7':
+            get_database_stats_cli()
+        elif choice == '0':
+            print("Goodbye!")
+            break
+        else:
+            print(" Invalid choice. Please try again.")
 
-user = login_user("alice@example.com")
-print(f"Welcome back, {user['name']}!")
+        press_enter_to_continue()
 
-analytics = get_user_analytics()
-print(f"Analytics: {analytics}")
+if __name__ == "__main__":
+    setup_database()
+    main_menu()