資料庫多行轉換為單一列

資料庫存儲與實際顯示需求不一樣時，我們得寫SQL來實現數據呈現：

如：

先來看看數據表：

CREATE TABLE [dbo].[Expenses]
(
    [Date] DATE,
    [Description] NVARCHAR(40),
    [Charge] DECIMAL(18,2)
)
GO

然後，我們為表填充一些數據，比如春節購買開支：

INSERT INTO [dbo].[Expenses] ([Date],[Description],[Charge]) VALUES 
('2020-01-22',N'魷魚',305.40),
('2020-01-22',N'豬肉',110.60),
('2020-01-22',N'青菜',36.90),
('2020-01-22',N'酒',30.00),
('2020-01-22',N'米',75.00),

('2020-01-23',N'魷魚',200.40),
('2020-01-23',N'豬肉',50.00),
('2020-01-23',N'青菜',14.30),
('2020-01-23',N'酒',30.00),
('2020-01-23',N'米',20.00),

('2020-01-24',N'魷魚',460.00),
('2020-01-24',N'豬肉',200.00),
('2020-01-24',N'青菜',90.00),
('2020-01-24',N'酒',50.00),
('2020-01-24',N'米',300.00)

GO

所有數據準備完畢，現在寫SQL來實現此功能：

SELECT E1.[Date],E1.[Charge] AS N'魷魚',E2.[Charge] AS N'豬肉',E3.[Charge] AS N'青菜',E4.[Charge] AS N'酒', E5.[Charge] AS N'米'  FROM
[dbo].[Expenses] AS E1,[dbo].[Expenses] AS E2,[dbo].[Expenses] AS E3,[dbo].[Expenses] AS E4,[dbo].[Expenses] AS E5
WHERE E1.[Date] = E2.[Date] AND E2.[Date] = E3.[Date] AND E3.[Date] = E4.[Date] AND E4.[Date] = E5.[Date]
AND E1.[Description] = N'魷魚' AND E2.[Description] = N'豬肉' AND E3.[Description] = N'青菜' AND E4.[Description] = N'酒' AND E5.[Description] = N'米'  
GO