按日期

Question

分組如何選擇SQL結果我想從按日期

date  btype  amount 
1-2-2017 income  1000 
1-2-2017 income  200 
1-2-2017 Expense  100 
1-2-2017 Expense  200 

2-2-2017 income  1000 
2-2-2017 income  500 
2-2-2017 Expense  1000 

3-2-2017 income  2000 
3-2-2017 Expense  500 

下表組，以便我的結果應該是這樣選擇的數據。

date  Income  Expense 
1-2-2017 1200  300 
2-2-2017 1500  1000 
3-2-2017 2000  500 

請問一些機構指導我如何編寫SQL查詢來實現這種行爲！

Answer 1

這是相當簡單的SQL，你應該能夠有點谷歌的找出自己：

select date 
     ,sum(if(btype = 'income', amount, 0)) as Income 
     ,sum(if(btype = 'expense', amount, 0)) as Expense 
from table 
group by date 

Answer 2

創建一個測試表後，我插入一些記錄，然後我用這個查詢：

select date_ as Date_Time, btype, sum(amount) as amount 
from test 
group by date_ , btype 

Answer 3

另一種方法

select date 
     ,sum(case when btype = 'income' then amount else 0 end) as Income 
     ,sum(case when btype = 'expense' then amount else 0 end) as Expense 
from table 
group by date