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48 lines
1.6 KiB
HTML
48 lines
1.6 KiB
HTML
<p>Table: <code>Person</code></p>
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<pre>
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+-------------+---------+
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| Column Name | Type |
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+-------------+---------+
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| id | int |
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| email | varchar |
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+-------------+---------+
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id is the primary key (column with unique values) for this table.
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Each row of this table contains an email. The emails will not contain uppercase letters.
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</pre>
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<p> </p>
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<p>Write a solution to<strong> delete</strong> all duplicate emails, keeping only one unique email with the smallest <code>id</code>.</p>
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<p>For SQL users, please note that you are supposed to write a <code>DELETE</code> statement and not a <code>SELECT</code> one.</p>
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<p>For Pandas users, please note that you are supposed to modify <code>Person</code> in place.</p>
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<p>After running your script, the answer shown is the <code>Person</code> table. The driver will first compile and run your piece of code and then show the <code>Person</code> table. The final order of the <code>Person</code> table <strong>does not matter</strong>.</p>
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<p>The result format is in the following example.</p>
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<p> </p>
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<p><strong class="example">Example 1:</strong></p>
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<pre>
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<strong>Input:</strong>
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Person table:
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+----+------------------+
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| id | email |
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+----+------------------+
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| 1 | john@example.com |
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| 2 | bob@example.com |
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| 3 | john@example.com |
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+----+------------------+
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<strong>Output:</strong>
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+----+------------------+
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| id | email |
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+----+------------------+
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| 1 | john@example.com |
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| 2 | bob@example.com |
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+----+------------------+
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<strong>Explanation:</strong> john@example.com is repeated two times. We keep the row with the smallest Id = 1.
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</pre>
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