如何更改行和列在SQL表

Question

SQL表结果像这样

InvoiceId Tax1 Tax1value Tax2 Tax2Value Tax3 Tax3Value 
10   GST 2.0  PST 2.8  GRT  3.1 

查询以获得上述结果

SELECT InvoiceId,Tax1,Tax1value,Tax2,Tax2value,Tax3,Tax3Value 
FROM Invoice 
WHERE InvoicId=10 

现在我需要的表输出一样的打击同一张发票上表

GST PST GRT 
2.0 2.8 3.1 

如何获得像这样的结果

Answer 1

有点像？

SELECT Tax1value AS GST, Tax2value AS PST, Tax3Value AS GRT 
FROM Invoice 
WHERE InvoiceId = 10 

从http://www.1keydata.com/sql/sql-as.html

所述关键字作为用于将别名分配给所述列或表。

结果会;

| GST | PST | GRT | 
|-----|-----|-----| 
| 2 | 3 | 3 | 

这里一个SQL Fiddle DEMO。

Answer 2

看到这个question，也许可能对你有用。

应用到你的情况是这样的：

SELECT 
    invoiceid, 
    MAX(CASE WHEN (tax1= 'GST') THEN tax1value ELSE NULL END) AS GST, 
    MAX(CASE WHEN (tax2 = 'PST') THEN tax2value ELSE NULL END) AS PST, 
    MAX(CASE WHEN (tax3 = 'GRT') THEN tax3value ELSE NULL END) AS GRT 
FROM 
    invoice 
GROUP BY invoiceid 
ORDER BY invoiceid