Combine Person and Address Data Using Join - PostgreSQL
Intuition\nThe problem requires combining information from two tables (Person and Address) based on a common personId. The goal is to retrieve the first name, l
# Intuition\nThe problem requires combining information from two tables (Person and Address) based on a common personId. The goal is to retrieve the first name, last name, city, and state for each person. If a person does not have an address (i.e., no corresponding entry in the Address table), we should return NULL values for city and state.\n\n# Approach\n1. Join Tables: Use a LEFT JOIN between the Person and Address tables on the personId column. This ensures that all rows from Person are included, regardless of whether there is a matching row in Address.\n\n2. Select Columns: Select the firstName, lastName, city, and state columns from the result of the join.\n\n# Complexity\n- Time complexity:\nThe time complexity of the SQL query depends on the size of the Person and Address tables and the efficiency of the join operation. Typically, for a left join operation, the time complexity is O(m+n), where m is the number of rows in Person and n is the number of rows in Address.\n\n- Space complexity:\nThe space complexity is primarily determined by the size of the result set returned by the query, which is O(m), where m is the number of rows in Person.\n\n# Code\n**PostgreSQL**\n```\n/* Write your PL/SQL query statement below */\nSELECT p.firstName, p.lastName, a.city, a.state\nFROM Person p\nLEFT JOIN Address a ON p.personId = a.personId;\n```
['PostgreSQL']