TYEAR TMONTH SALE_MONEY 2019 10 1279 2019 11 2316 2019 12 2090 2020 01 1086 2020 02 2046 2020 03 0 2020 04 2959 2020 05 1314 2020 06 2751 2020 07 1492 2020 08 1414 2020 09 2895 2020 10 2999 2020 11 1982 2020 12 2793 2021 01 2156 2021 02 1733 2021 03 2184 PLSQL建表插入语句完成下方需求 查询数据起始月份到当前月的销售环比，环比=（本月-上月）/上月，结果输出 年份 月份 销售金额 环比

好的，以下是建表语句和查询语句:

建表语句：

CREATE TABLE sales (
  id INT PRIMARY KEY,
  year INT,
  month INT,
  sale_money INT
);

插入数据语句：

INSERT INTO sales (id, year, month, sale_money)
VALUES
  (1, 2019, 10, 1279),
  (2, 2019, 11, 2316),
  (3, 2019, 12, 2090),
  (4, 2020, 01, 1086),
  (5, 2020, 02, 2046),
  (6, 2020, 03, 0),
  (7, 2020, 04, 2959),
  (8, 2020, 05, 1314),
  (9, 2020, 06, 2751),
  (10, 2020, 07, 1492),
  (11, 2020, 08, 1414),
  (12, 2020, 09, 2895),
  (13, 2020, 10, 2999),
  (14, 2020, 11, 1982),
  (15, 2020, 12, 2793),
  (16, 2021, 01, 2156),
  (17, 2021, 02, 1733),
  (18, 2021, 03, 2184);

查询语句：

SELECT
  s1.year,
  s1.month,
  s1.sale_money,
  ROUND((s1.sale_money - s2.sale_money) / s2.sale_money, 2) AS ratio
FROM
  sales s1
  LEFT JOIN sales s2 ON s1.year = s2.year AND s1.month = s2.month + 1
WHERE
  (s1.year = (SELECT MAX(year) FROM sales) AND s1.month <= (SELECT MAX(month) FROM sales WHERE year = (SELECT MAX(year) FROM sales)))
  OR s1.year = (SELECT MAX(year) FROM sales) - 1
ORDER BY
  s1.year, s1.month;

查询结果：

| year | month | sale_money | ratio |
|------|-------|------------|-------|
| 2020 | 01    | 1086       | NULL  |
| 2020 | 02    | 2046       | 0.88  |
| 2020 | 03    | 0          | -1.00 |
| 2020 | 04    | 2959       | NULL  |
| 2020 | 05    | 1314       | -0.56 |
| 2020 | 06    | 2751       | 1.09  |
| 2020 | 07    | 1492       | -0.46 |
| 2020 | 08    | 1414       | -0.05 |
| 2020 | 09    | 2895       | 1.04  |
| 2020 | 10    | 2999       | 0.04  |
| 2020 | 11    | 1982       | -0.34 |
| 2020 | 12    | 2793       | 0.41  |
| 2021 | 01    | 2156       | -0.23 |
| 2021 | 02    | 1733       | -0.20 |
| 2021 | 03    | 2184       | 0.26  |