掌握 SQL SELECT 语句：综合指南

<code class="sql">SELECT column1, column2, ...
FROM table_name
WHERE condition
ORDER BY column_name [ASC|DESC];</code>

<code class="sql">SELECT first_name, last_name FROM employees;</code>

<code class="sql">SELECT * FROM orders;</code>

<code class="sql">SELECT * FROM customers WHERE city = 'New York';</code>

<code class="sql">SELECT * FROM products ORDER BY price DESC;</code>

<code class="sql">SELECT department, COUNT(*) AS employee_count FROM employees GROUP BY department;</code>

<code class="sql">SELECT department, COUNT(*) AS employee_count FROM employees 
GROUP BY department 
HAVING COUNT(*) > 10;</code>

<code class="sql">SELECT * FROM employees;</code>

<code class="sql">SELECT first_name, last_name FROM employees;</code>

<code class="sql">SELECT first_name AS "First Name", last_name AS "Last Name" FROM employees;</code>

<code class="sql">SELECT * FROM orders WHERE order_date = '2024-01-01';</code>

<code class="sql">SELECT * FROM products ORDER BY price ASC;</code>

<code class="sql">SELECT COUNT(*) AS total_employees FROM employees;</code>

<code class="sql">SELECT department, AVG(salary) AS average_salary FROM employees GROUP BY department;</code>

<code class="sql">SELECT * FROM customers WHERE city = 'London' AND age > 30;</code>

<code class="sql">SELECT * FROM products LIMIT 5;</code>

<code class="sql">SELECT employees.first_name, departments.department_name
FROM employees
JOIN departments ON employees.department_id = departments.department_id;</code>