Add initial project files: .gitignore, VSCode settings, and README for Leetcode SQL problems

Author: trinhminhtriet

.gitignore

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+.DS_Store

.vscode/settings.json

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+{
+    "editor.formatOnPaste": true
+}

README.md

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+# Leetcode | Top SQL 50
+
+01. [Recyclable and Low Fat Products](solutions/01.1757.recyclable-and-low-fat-products/README.md)

solutions/01.1757.recyclable-and-low-fat-products/README.md

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+---
+comments: true
+difficulty: Easy
+tags:
+    - Database
+---
+
+<!-- problem:start -->
+
+# [1757. Recyclable and Low Fat Products](https://leetcode.com/problems/recyclable-and-low-fat-products)
+
+## Description
+
+<!-- description:start -->
+
+<p>Table: <code>Products</code></p>
+
+<pre>
++-------------+---------+
+| Column Name | Type    |
++-------------+---------+
+| product_id  | int     |
+| low_fats    | enum    |
+| recyclable  | enum    |
++-------------+---------+
+product_id is the primary key (column with unique values) for this table.
+low_fats is an ENUM (category) of type (&#39;Y&#39;, &#39;N&#39;) where &#39;Y&#39; means this product is low fat and &#39;N&#39; means it is not.
+recyclable is an ENUM (category) of types (&#39;Y&#39;, &#39;N&#39;) where &#39;Y&#39; means this product is recyclable and &#39;N&#39; means it is not.</pre>
+
+<p>&nbsp;</p>
+
+<p>Write a solution to find the ids of products that are both low fat and recyclable.</p>
+
+<p>Return the result table in <strong>any order</strong>.</p>
+
+<p>The result format is in the following example.</p>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+
+<pre>
+<strong>Input:</strong> 
+Products table:
++-------------+----------+------------+
+| product_id  | low_fats | recyclable |
++-------------+----------+------------+
+| 0           | Y        | N          |
+| 1           | Y        | Y          |
+| 2           | N        | Y          |
+| 3           | Y        | Y          |
+| 4           | N        | N          |
++-------------+----------+------------+
+<strong>Output:</strong> 
++-------------+
+| product_id  |
++-------------+
+| 1           |
+| 3           |
++-------------+
+<strong>Explanation:</strong> Only products 1 and 3 are both low fat and recyclable.
+</pre>
+
+<!-- description:end -->
+
+## Solutions
+
+<!-- solution:start -->
+
+### Solution 1: Conditional Filtering
+
+We can directly filter the product IDs where `low_fats` is `Y` and `recyclable` is `Y`.
+
+<!-- tabs:start -->
+
+#### Python3
+
+```python
+import pandas as pd
+
+
+def find_products(products: pd.DataFrame) -> pd.DataFrame:
+    rs = products[(products["low_fats"] == "Y") & (products["recyclable"] == "Y")]
+    rs = rs[["product_id"]]
+    return rs
+```
+
+#### MySQL
+
+```sql
+SELECT
+    product_id
+FROM Products
+WHERE low_fats = 'Y' AND recyclable = 'Y';
+```
+
+<!-- tabs:end -->
+
+<!-- solution:end -->
+
+<!-- problem:end -->