leetcode problem 2889 reshape data pivot

Okay, let's dive deep into LeetCode problem 2889: Reshape Data: Pivot. This is a SQL problem that challenges you to pivot a table, which is a fundamental data transformation technique. I'll provide a comprehensive explanation, covering the problem statement, the concept of pivoting, different approaches to solving it in SQL, potential challenges, and optimization tips.

**Problem Statement (LeetCode 2889: Reshape Data: Pivot)**

You are given a table named `Products` with the following structure:

| Column Name | Type |
|-------------|---------|
| product_id | int |
| store | varchar |
| price | int |

Each row represents the price of a specific product in a specific store.

Your task is to reshape the `Products` table into a pivoted table where:

* The `product_id` column becomes the row identifier.
* Each distinct `store` value becomes a column (e.g., `store1`, `store2`, `store3`).
* The values in the pivoted columns are the corresponding `price` values for that product in that store. If a product doesn't exist in a particular store, the value should be `NULL`.

The pivoted table should have the following columns:

| Column Name | Type |
|-------------|------|
| product_id | int |
| store1 | int |
| store2 | int |
| store3 | int |

**Example:**

**Input Table `Products`:**

| product_id | store | price |
|------------|--------|-------|
| 0 | store1 | 100 |
| 0 | store3 | 150 |
| 1 | store1 | 200 |
| 1 | store2 | 250 |
| 2 | store1 | 300 |
| 2 | store2 | 350 |
| 2 | store3 | 400 |

**Output Table:**

| product_id | store1 | store2 | store3 |
|------------|--------|--------|--------|
| 0 | 100 | NULL | 150 |
| 1 | 200 | 250 | NULL |
| 2 | 300 | 350 | 400 |

**Understanding Pivoting**

Pivoting (also sometimes called "crosstab" or "matrix transformation") is a data transformation techniqu ...

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