sql group by date每天给出相同的值

Question

所以我想按天划分统计数据，所以我每天都有数据（类型1已购买，0已售出），但查询每天给我相同的结果，这是不正确的，有人可以帮我这个代码？

SELECT 
            DATE(from_unixtime(credit_transaction_time)) AS data_date,
            total_spend AS credits_spend,
            total_bought AS credits_bought
        FROM credit_transactions
            JOIN (SELECT SUM(`credit_transaction_amount`) AS total_spend FROM credit_transactions WHERE `credit_transaction_type` = 0 GROUP BY DATE(from_unixtime(credit_transaction_time))) AS spend
            JOIN (SELECT SUM(`credit_transaction_amount`) AS total_bought FROM credit_transactions WHERE `credit_transaction_type` = 1 GROUP BY DATE(from_unixtime(credit_transaction_time))) AS bought
        GROUP BY DATE(from_unixtime(credit_transaction_time))

Answer 1

使用条件聚合：

DbFunctions

您的查询不起作用，因为您没有SELECT DATE(from_unixtime(credit_transaction_time)) AS data_date, SUM(CASE WHEN credit_transaction_type = 0 THEN credit_transaction_amount ELSE 0 END) as credits_spend, SUM(CASE WHEN credit_transaction_type = 1 THEN credit_transaction_amount ELSE 0 END) as credits_bought FROM credit_transactions GROUP BY DATE(from_unixtime(credit_transaction_time)); 条件。在大多数数据库中，这会导致语法错误，但MySQL允许这种语法。