added postgresql files

app.py

 # importing library
-from scripts.services.crud_operations import start_crud_operation
+from scripts.services.crud_operations import start_crud_operation_mongodb, start_crud_operations_postgresql
 
-# calling function to perform crud operations
-start_crud_operation()
+print("-----CRUD Operations-----\n"
+      "1.MongoDB\n"
+      "2.PostgreSQL\n")
+# choose which method to start first
+choice = int(input("Enter your choice: "))
+
+
+# check which option is entered
+if choice == 1:
+    # calling function to perform crud operations in mongoDB
+    start_crud_operation_mongodb()
+elif choice == 2:
+    # calling function to perform crud operations in postgresqlDB
+    start_crud_operations_postgresql()

scripts/core/handlers/delete_postgresql.py

+def delete_row(connection):
+    try:
+        cursor = connection.cursor()
+        print("------DELETE OPERATION------\n")
+        license_no = input("Enter the license no")
+        delete_data = f'DELETE FROM tbl_company WHERE license_no={license_no}'
+        cursor.execute(delete_data)
+        connection.commit()
+        print("Row deleted successfully!")
+    except Exception as e:
+        print("Error ", e)

scripts/core/handlers/get_data_postgresql.py

+def data_from_user():
+    company_license_no = input("Enter the company license no: ")
+    company_name = input("Enter the company name: ")
+    market_cap = input("Enter the market capital: ")
+    revenue_change = input("Enter the revenue change: ")
+    pat_change = input("Enter the pat change: ")
+    company_document = (company_license_no, company_name, market_cap, revenue_change, pat_change)
+    return company_document

scripts/core/handlers/insert.py → scripts/core/handlers/insert_mongodb.py

-from scripts.core.handlers.get_data import data_from_user
+from scripts.core.handlers.get_data_mongodb import data_from_user
 
 
 def inserting_one(company_collection):

scripts/core/handlers/insert_postgresql.py

+from scripts.core.handlers.get_data_postgresql import data_from_user
+
+
+def insert(connection):
+    cursor = connection.cursor()
+    print("------INSERT OPERATION------\n")
+    insert_table = "INSERT INTO tbl_company(license_no, company_name, market_cap,revenue_change, pat_change) VALUES(" \
+                   "%s,%s,%s,%s,%s)"
+    row_value = data_from_user()
+    cursor.execute(insert_table, row_value)
+    connection.commit()
+    count = cursor.rowcount
+    print(count, "Record inserted successfully into tbl_company table")

scripts/core/handlers/read_data_postgresql.py

+def read_data(connection):
+    try:
+        cursor = connection.cursor()
+        print("------SELECT OPERATION------\n")
+        view_data = "SELECT * FROM tbl_company"
+        cursor.execute(view_data)
+        company_records = cursor.fetchall()
+        print("Each row and it's columns values")
+        for row in company_records:
+            print("license_no = ", row[0])
+            print("company_name = ", row[1])
+            print("market_cap = ", row[2])
+            print("revenue_change = ", row[3])
+            print("pat_change  = ", row[4], "\n")
+    except Exception as e:
+        print("Error ", e)

scripts/core/handlers/update_postgresql.py

+def update_row(connection):
+    try:
+        cursor = connection.cursor()
+        print("------UPDATE OPERATION------\n")
+        license_no = input("Enter the license no")
+        print("Choose the field you want to update\n"
+              "1.company_name\n"
+              "2.market_cap\n"
+              "3.revenue_change\n"
+              "4.pat_change\n")
+        field_choice = int(input("Enter your choice: "))
+        if field_choice == 1:
+            update_data = input("Enter the data: ")
+            update_query = f'update tbl_company SET company_name ={update_data} where license_no={license_no}'
+        else:
+            if field_choice == 2:
+                field_to_update = "market_cap"
+            elif field_choice == 3:
+                field_to_update = "revenue_change"
+            elif field_choice == 4:
+                field_to_update = "pat_change"
+            update_data = input("Enter the data: ")
+            update_query = f'UPDATE tbl_company SET {field_to_update}={update_data} WHERE license_no={license_no}'
+        cursor.execute(update_query)
+        connection.commit()
+        print("Row updated successfully!")
+    except Exception as e:
+        print("Error ", e)

scripts/db_connection/postgreSQL_connect.py

+import psycopg2
+
+
+def connect_db():
+    try:
+        connection = psycopg2.connect(user="postgres",
+                                      password="test",
+                                      host="127.0.0.1",
+                                      port="5432",
+                                      database="company_db")
+
+        return connection
+    except (Exception, psycopg2.Error) as error:
+        print("Failed to Connect to DB", error)

scripts/services/crud_operations.py

-from scripts.core.handlers.mongodb_connect import db_connect
-from scripts.core.handlers.insert import inserting_one, inserting_many
-from scripts.core.handlers.read_documents import finding_one, finding_many
-from scripts.core.handlers.delete import delete_one_document, delete_many_document
-from scripts.core.handlers.update import update_one_document, update_many_document
+from scripts.db_connection.mongodb_connect import db_connect
+from scripts.db_connection.postgreSQL_connect import connect_db
+from scripts.core.handlers.insert_mongodb import inserting_one, inserting_many
+from scripts.core.handlers.read_documents_mongodb import finding_one, finding_many
+from scripts.core.handlers.delete_mongodb import delete_one_document, delete_many_document
+from scripts.core.handlers.update_mongodb import update_one_document, update_many_document
+from scripts.core.handlers.insert_postgresql import insert
+from scripts.core.handlers.read_data_postgresql import read_data
+from scripts.core.handlers.delete_postgresql import delete_row
+from scripts.core.handlers.update_postgresql import update_row
 
-def start_crud_operation():
+
+def start_crud_operation_mongodb():
     try:
         # create a db connection
         db = db_connect()
@@ -12,32 +18,58 @@ def start_crud_operation():
         # create a collection
         company_collection = db['company']
 
-
         # inserting one document
         inserting_one(company_collection)
 
         # finding more than one document
         inserting_many(company_collection)
 
-
         # finding one document
         finding_one(company_collection)
 
         # inserting more than one document
         finding_many(company_collection)
 
-
         # updating one document
         update_one_document(company_collection)
 
         # updating many documents
         update_many_document(company_collection)
 
-
         # deleting one document
         delete_one_document(company_collection)
 
         # deleting many documents
         delete_many_document(company_collection)
     except Exception as e:
-        print("Error-", e)
\ No newline at end of file
+        print("Error-", e)
+
+
+def start_crud_operations_postgresql():
+    try:
+        postgresql_connection = connect_db()
+        cursor = postgresql_connection.cursor()
+        # checking if the table exists
+        cursor.execute(f"SELECT * FROM  information_schema.tables WHERE table_name = 'tbl_company'")
+        if cursor.fetchone():
+            print("Table Already Exists!")
+        else:
+            postgres_create_query = """CREATE TABLE tbl_company (license_no INT,
+                                                                 company_name CHAR(50) NOT NULL, 
+                                                                 market_cap INT NOT NULL,
+                                                                 revenue_change INT NOT NULL,
+                                                                 pat_change INT NOT NULL,
+                                                                 PRIMARY KEY( license_no ))"""
+            cursor.execute(postgres_create_query)
+            postgresql_connection.commit()
+            print("Table Created!")
+        # inserting records in the table
+        insert(postgresql_connection)
+        # read or selecting the data in the table
+        read_data(postgresql_connection)
+        # updating data in the table based on the license number user entered
+        update_row(postgresql_connection)
+        # deleting data in the table based on the license number user entered
+        delete_row(postgresql_connection)
+    except Exception as e:
+        print("Error-", e)