Oracle SQL日期问题：查询最近入职员工姓名

Hey there! Let's figure out how to pull the list of employees who joined the company most recently using Oracle SQL. Here's a breakdown tailored to your data and requirements:

What We Need to Do #

Retrieve the names of employees with the latest joining date from the provided employee dataset.

Sample Input Data #

Expected Output #

Solution 1: Simple Subquery Approach #

This is the most straightforward method—first find the latest joining date, then filter employees who match that date:

SELECT emp, "Date of joining" AS "Date of Joining"
FROM your_employee_table
WHERE "Date of joining" = (SELECT MAX("Date of joining") FROM your_employee_table)
ORDER BY emp;

How it works:

• The subquery (SELECT MAX("Date of joining") FROM your_employee_table) grabs the most recent joining date in the table.
• The main query returns all employees whose joining date matches this maximum value.
• The ORDER BY emp clause sorts results alphabetically, matching your desired output order.

Solution 2: Window Function (RANK()) Approach #

If you need more flexibility (like fetching the top 2 most recent hiring batches later), use a window function:

WITH ranked_hires AS (
    SELECT 
        emp, 
        "Date of joining" AS "Date of Joining",
        RANK() OVER (ORDER BY "Date of joining" DESC) AS hire_rank
    FROM your_employee_table
)
SELECT emp, "Date of Joining"
FROM ranked_hires
WHERE hire_rank = 1
ORDER BY emp;

How it works:

• The CTE (ranked_hires) assigns a rank to each employee based on their joining date—those with the latest date get a rank of 1.
• We select only rows where hire_rank = 1 to get all the most recent hires.
• This method scales easily: if you ever need employees from the next most recent joining date, just adjust the WHERE clause to hire_rank <= 2.

Important Notes: #

• Replace your_employee_table with the actual name of your employee table in Oracle.
• Since the column name has spaces, we use double quotes ("Date of joining") to reference it correctly (Oracle is case-sensitive with quoted identifiers).

内容的提问来源于stack exchange，提问作者bradon Mc