SQL 条件聚合
示例
付款表
select customer,
sum(case when payment_type = 'credit' then amount else 0 end) as credit,
sum(case when payment_type = 'debit' then amount else 0 end) as debit
from payments
group by customer结果：
select customer,
sum(case when payment_type = 'credit' then 1 else 0 end) as credit_transaction_count,
sum(case when payment_type = 'debit' then 1 else 0 end) as debit_transaction_count
from payments
group by customer结果：
热门推荐
10 财运虎年祝福语简短语
11 单亲爸爸春节祝福语简短
12 狗狗上厕所训练
13 植物种植祝福语简短
14 翻译考试祝福语朋友简短
15 个人周年庆简短祝福语
16 狗狗怎么训练
17 分别祝福语简短搞笑英文
18 生日广州男生祝福语简短