每月交易次数（从 2014 年到 2016 年）

如果我正确理解您的问题，您只需添加收入和年份组的总和。

试试这个：

SELECT 
    COUNT(*) as test, 
    SUM(EarnValue) as Total, 
    YEAR(TxnDate) as Year, 
    MONTH(TxnDate) as Month 
FROM fschevrondata 
WHERE 
    YEAR(TxnDate) >= 2014 -- or this can be TxnDate >= '2014-01-01'
    AND YEAR(TxnDate) <= 2016 -- or this can be TxnDate <= '2016-12-31'
GROUP BY 
    YEAR(TxnDate), 
    MONTH(TxnDate)