单个SQL查询中的多个计数（事务类型）

Question

因此，我有一个用于企业所有交易的表格，非常简单，它有一个付款方式列，该列列出了如何进行所有交易（现金，贷方或借方）。

我想要做的是使用查询创建两列，该列计算出每笔交易的完成方式，一列是现金，另一列是Card，其中包括所有的信用卡和借记卡购买。

这是我到目前为止的内容：

SELECT COUNT (*) as CashTransactions
FROM Transaction
WHERE PaymentMethod='Cash'

我想要的输出是

Cash Transactions  |       Card Transactions

 (Count of Cash)   |  (Count of Credit AND Debit)

Answer 1

这里有几个选择。 我强烈建议选择一种，它更清洁，更快。

选项1 ：

SELECT PaymentMethod, COUNT(*) AS NumberOfTransactions
FROM Transaction
GROUP BY PaymentMethod

导致：

PaymentMethod | NumberOfTransactions
------------------------------------
Cash          | 33
Credit        | 12
Debit         | 87

或选项2 ：

SELECT (
SELECT COUNT(*) AS NumberOfTransactions
FROM Transaction
WHERE PaymentMethod = 'Cash'
) as CashTransactions,
(
SELECT COUNT(*) AS NumberOfTransactions
FROM Transaction
WHERE NOT PaymentMethod = 'Cash'
) as OtherTransactions

导致：

CashTransactions| OtherTransactions
------------------------------------
33              | 99

Answer 2

如果使用SQL Server，则可以尝试以下查询：

SELECT 
   SUM(CASE WHEN PaymentMethod='Cash' THEN 1 ELSE 0 END) as CashTransaction,
   SUM(CASE WHEN PaymentMethod IN ('Credit','Debit') THEN 1 ELSE 0 END) as CardTransaction 
FROM Transaction

但是，如果在查询中使用ms-access，则可以尝试以下查询：

SELECT sum(IIF(PaymentMethod='Cash',1,0)) as CashTransaction, sum(IIF(PaymentMethod in ('Credit','Debit'),1,0)) as CardTransaction
FROM Transaction;

Answer 3

只是总结而不是计数：

SELECT 
    ABS(SUM(PaymentMethod = 'Cash')) AS CashTransactions,
    ABS(SUM(PaymentMethod <> 'Cash')) AS CardTransactions
FROM 
    Transaction