国外版

算法题（国外版）/daily-leads-and-partners.html

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+<p>Table: <code>DailySales</code></p>
+
+<pre>
++-------------+---------+
+| Column Name | Type    |
++-------------+---------+
+| date_id     | date    |
+| make_name   | varchar |
+| lead_id     | int     |
+| partner_id  | int     |
++-------------+---------+
+This table does not have a primary key.
+This table contains the date and the name of the product sold and the IDs of the lead and partner it was sold to.
+The name consists of only lowercase English letters.
+</pre>
+
+<p>&nbsp;</p>
+
+<p>Write an SQL query that will, for each <code>date_id</code> and <code>make_name</code>, return the number of <strong>distinct</strong> <code>lead_id</code>&#39;s and <strong>distinct</strong> <code>partner_id</code>&#39;s.</p>
+
+<p>Return the result table in <strong>any order</strong>.</p>
+
+<p>The query result format is in the following example.</p>
+
+<p>&nbsp;</p>
+<p><strong>Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> 
+DailySales table:
++-----------+-----------+---------+------------+
+| date_id   | make_name | lead_id | partner_id |
++-----------+-----------+---------+------------+
+| 2020-12-8 | toyota    | 0       | 1          |
+| 2020-12-8 | toyota    | 1       | 0          |
+| 2020-12-8 | toyota    | 1       | 2          |
+| 2020-12-7 | toyota    | 0       | 2          |
+| 2020-12-7 | toyota    | 0       | 1          |
+| 2020-12-8 | honda     | 1       | 2          |
+| 2020-12-8 | honda     | 2       | 1          |
+| 2020-12-7 | honda     | 0       | 1          |
+| 2020-12-7 | honda     | 1       | 2          |
+| 2020-12-7 | honda     | 2       | 1          |
++-----------+-----------+---------+------------+
+<strong>Output:</strong> 
++-----------+-----------+--------------+-----------------+
+| date_id   | make_name | unique_leads | unique_partners |
++-----------+-----------+--------------+-----------------+
+| 2020-12-8 | toyota    | 2            | 3               |
+| 2020-12-7 | toyota    | 1            | 2               |
+| 2020-12-8 | honda     | 2            | 2               |
+| 2020-12-7 | honda     | 3            | 2               |
++-----------+-----------+--------------+-----------------+
+<strong>Explanation:</strong> 
+For 2020-12-8, toyota gets leads = [0, 1] and partners = [0, 1, 2] while honda gets leads = [1, 2] and partners = [1, 2].
+For 2020-12-7, toyota gets leads = [0] and partners = [1, 2] while honda gets leads = [0, 1, 2] and partners = [1, 2].
+</pre>