import unittest
import psycopg2
import pandas as pd

class TestPostgresQuery(unittest.TestCase):
    @classmethod
    def setUpClass(cls):
        cls.connection = psycopg2.connect(
            host="localhost",
            user="agent",
            password="qwerty",
            dbname="testdb",
            sslmode="disable"
        )
        cls.cursor = cls.connection.cursor()

    def test_query_selects_all_columns(self):
        """Check if query selects all columns from customers."""
        with open("query.sql", "r") as file:
            query = file.read()
        self.cursor.execute(query)
        columns = [desc[0] for desc in self.cursor.description]
        expected_columns = ['id', 'name', 'city', 'signup_date']
        condition = set(expected_columns) == set(columns)
        _dynamic_test(
            self,
            condition,
            "Query selects all columns from customers.",
            f"Query does not select all columns from customers. Columns found: {columns}"
        )

    def test_query_returns_all_records(self):
        """Check if query returns all 10 records from customers."""
        with open("query.sql", "r") as file:
            query = file.read()
        self.cursor.execute(query)
        rows = self.cursor.fetchall()
        condition = len(rows) == 10
        _dynamic_test(
            self,
            condition,
            "Query returns all 10 records from customers.",
            f"Query returned {len(rows)} records instead of 10."
        )

def _dynamic_test(test_case, condition, success_message, failure_message):
    if condition:
        test_case._testMethodName = success_message
        test_case.assertTrue(True, success_message)
    else:
        test_case._testMethodName = failure_message
        test_case.fail(failure_message)

def normalize_text(text):
    text = text.lower()
    text = re.sub(r"\\s{2,}", " ", text)
    text = re.sub(r"\\s*([,:?])\\s*", r"\\1 ", text)
    return text.strip()

if __name__ == "__main__":
    unittest.main()


test_solution.py

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Learn the foundational concepts of relational databases and SQL. Explore how to retrieve, filter, and sort data from tables, setting the stage for deeper data analysis.

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Challenge: Exploring Customer Data

Ratkaisu

Challenge: Exploring Customer Data

Ratkaisu