合并 SQL 服务器中的 table 列

Question

当 Customer_address 相同 address_index 但不同 line_nbr 时，我必须合并它们：

CUSTOMER_NUM	CUSTOMER_CODE	CUSTOMER_ADDRSS	LINE_NBR	ADDRESS_INDEX	ADDRESS_CODE
31	GEW	3901 Castle Hayne Road	17	1	SHIP
30	GEW	Highway 117 N	18	1	SHIP
212	GEW	1005 2nd Street	19	2	SHIP
23	GEW	3901 Castle Hayne Road	20	3	SHIP
241	GEW	Highway 117 N	21	3	SHIP
360	GEW	465 McCarthy Road	1	4	SHIP
469	GEW	3901 Castle Hayne Road	1	5	SHIP
470	GEW	Highway 117 N	2	5	SHIP

我需要结合CUSTOMER_NUM 31和30阅读

Castle Hayne Road Highway 117 N

通过组合 Address_index = 1 与 Line_nbr 17 和 18，以及 Address_index = 3 与 line_nbr 20 和 21，以及 Address_index 5 与 line_nbr 1 和 2，等等......

SQL 的新手，正在尝试弄清楚如何 link 将两列放在一起并在一列而不是当前所在的两行中写出客户地址。

Answer 1

在 SQL Server 2017+ 上，STRING_AGG() 使这变得简单：

SELECT CUSTOMER_CODE, 
       MergedAddress = STRING_AGG(CUSTOMER_ADDRSS, ' ') 
                       WITHIN GROUP (ORDER BY LINE_NBR)
  FROM dbo.MyTable
  GROUP BY CUSTOMER_CODE, ADDRESS_INDEX;

输出：

CUSTOMER_CODE	MergedAddress
GEW	3901 Castle Hayne Road Highway 117 N
GEW	1005 2nd Street
GEW	3901 Castle Hayne Road Highway 117 N
GEW	465 McCarthy Road
GEW	3901 Castle Hayne Road Highway 117 N

在旧版本上，您将不得不使用更麻烦且效率低下的方法，例如：

SELECT CUSTOMER_CODE, 
       MergedAddress = RTRIM((SELECT CUSTOMER_ADDRSS + ' '
         FROM dbo.MyTable AS inside
         WHERE inside.ADDRESS_INDEX = outside.ADDRESS_INDEX
         ORDER BY LINE_NBR
         FOR XML PATH(''), TYPE).value(N'./text()[1]', N'varchar(max)'))
  FROM dbo.MyTable AS outside 
  GROUP BY CUSTOMER_CODE, ADDRESS_INDEX;

example db<>fiddle 显示了结果以及应该有助于解释为什么后者如此糟糕的计划。

合并 SQL 服务器中的 table 列

Combining table column in SQL Server

sql-server

sql-server-2017