I am close to the end of a 10-day coding challenge organized by Ingressive for Good and I'll be sharing my thoughts on Day 8 of the challenge.
Let me briefly describe how the challenge works before I share my experience with you. From September 21 through October 30, 2022, the challenge is to solve one common algorithm problem every day for ten days.
Today's algorithm problem was "Combine Two Tables" It is the 175th algorithm challenge on "Leetcode.com".
Here is the question:
Table: Person
+-------------+---------+
| Column Name | Type |
+-------------+---------+
| personId | int |
| lastName | varchar |
| firstName | varchar |
+-------------+---------+
personId is the primary key column for this table.
This table contains information about the ID of some persons and their first and last names.
Table: Address
+-------------+---------+
| Column Name | Type |
+-------------+---------+
| addressId | int |
| personId | int |
| city | varchar |
| state | varchar |
+-------------+---------+
addressId is the primary key column for this table.
Each row of this table contains information about the city and state of one person with ID = PersonId.
Write an SQL query to report the first name, last name, city, and state of each person in the Person table. If the address of a personId is not present in the Address table, report null instead.
Return the result table in any order.
I visited w3schools.com to learn more about MySQL because I had never used it to resolve issue. As a result, I used the SELECT command to retrieve fields from the person table and the LEFT JOIN command to join the address table to the person table.
This task was completed in MySQL, took 525 milliseconds to execute, and consumed 0B of memory.
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