Duplicate Emails - Leetcode Solution

Problem Statement:

The problem of Duplicate Emails on Leetcode is as follows:

Suppose you have a table named Person with the following columns:

• Id: Intege
• Email: String

Write an SQL query to find all duplicate emails in the Person table.

Solution:

There are different ways to solve the problem of Duplicate Emails on Leetcode, but one possible solution using SQL can be as follows:

SELECT Email FROM Person GROUP BY Email HAVING COUNT(*) > 1;

Explanation:

The solution above uses SQL commands to find the duplicate emails in the Person table. Here's how it works:

• The SELECT statement selects the Email column from the Person table. This will give us a list of all the unique emails in the table.
• The GROUP BY statement groups the rows by their email addresses. This means that we'll get one row for each email address in the table.
• The HAVING clause specifies a condition that must be true for the selected rows to be included in the result. In this case, we want to include only those email addresses that appear more than once in the table. The COUNT(*) function counts the number of rows in each group, and the > operator compares this count to 1.

The result of the above SQL query will be a list of all the duplicate emails in the Person table.

Conclusion:

The Duplicate Emails problem on Leetcode can be solved using SQL in a few simple steps. By grouping the rows by their email addresses and counting the number of rows in each group, we can easily identify the duplicate emails in the table. This solution can be useful in real-world scenarios where data is stored in a database and we need to identify repetitions or inconsistencies in the data.

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