如何对多列求和并获取每列总计？SQL查询问题求助

你的SQL语句里加了GROUP BY borrower，这会让结果按每个借款人分组计算各列的和，而非你想要的全表总计，这就是结果不符合预期的原因。

要获取全表各列的总计，直接去掉GROUP BY子句即可，同时调整别名匹配你期望的格式：

SELECT 
  SUM(collateral_amount) AS collateral_amount,
  SUM(id) AS id,
  SUM(withdraw_amount) AS withdraw_collateral,
  SUM(total_amount_to_treasure) AS total_amount
FROM loans;

这条语句会返回一行数据，包含各列的全表总计值，和你期望的结构对应。

如果想要直接输出JSON格式的结果（以MySQL为例），可以使用JSON_OBJECT函数：

SELECT JSON_OBJECT(
  'collateral_amount', SUM(collateral_amount),
  'id', SUM(id),
  'withdraw_collateral', SUM(withdraw_amount),
  'total_amount', SUM(total_amount_to_treasure)
) AS total_summary
FROM loans;

执行后就能得到你给出的JSON格式的总计结果。

内容的提问来源于stack exchange，提问作者test_