-- 获取当前日期
SELECT current_date;

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-- 获取当前年和月
SELECT year(current_date) AS current_year, month(current_date) AS current_month;

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-- 计算上一个月份的年份
SELECT 
    CASE 
        WHEN month(current_date) = 1 THEN year(current_date) - 1
        ELSE year(current_date)
    END AS last_year;

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-- 计算上一个月份
SELECT 
    CASE 
        WHEN month(current_date) = 1 THEN 12
        ELSE month(current_date) - 1
    END AS last_month;

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-- 创建表
CREATE TABLE IF NOT EXISTS last_months (
    year INT,
    month INT
);

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-- 将上个月和年份插入表中
INSERT INTO last_months
SELECT 
    CASE 
        WHEN month(current_date) = 1 THEN year(current_date) - 1
        ELSE year(current_date)
    END AS last_year,
    CASE 
        WHEN month(current_date) = 1 THEN 12
        ELSE month(current_date) - 1
    END AS last_month;

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