SQL 服务器 - 编写查询以规范化构造不当的模式中的逗号分隔值

Question

问题：我正在查询规范化程度很低的数据库（我对数据的设计没有发言权，也无法更改它）

给定以下数据库：

------------------------------------------
|      Name      |         Codes          |
------------------------------------------
|       Josh     |    A2A-8292            |
-------------------------------------------
|       Adam     |    D2C-1292, B2A-7292  |
-------------------------------------------
|       Jery     |    A2A-1292, F2A-2292, | 
|                |    C2A-2292            |
-------------------------------------------

如何编写 returns 规范化版本的查询，例如：

 ------------------------------------------
|      Name      |         Codes          |
------------------------------------------
|       Josh     |    A2A-8292            |
-------------------------------------------
|       Adam     |    D2C-1292            |
-------------------------------------------
|       Adam     |    B2A-7292            |
-------------------------------------------
|       Jery     |    A2A-1292            |
-------------------------------------------
|       Jery     |    F2A-2292            |
-------------------------------------------
|       Jery     |    C2A-2292            |
-------------------------------------------

Answer 1

从这个答案中获取字符串拆分函数：T-SQL split string

您可以运行您的查询如下：

SELECT T.Name, X.*
FROM TABLE AS T
CROSS APPLY dbo.splitstring(Codes) AS X;

Answer 2

如果您不能使用 TVF，这里有另一个选择

例子

Select A.Name 
      ,B.*
 From  YourTable A
 Cross Apply (
                Select RetSeq = row_number() over (order by (Select null))
                      ,RetVal = ltrim(rtrim(B2.i.value('(./text())[1]', 'varchar(max)')))
                From  (Select x = Cast('<x>' + replace(Codes,',','</x><x>')+'</x>' as xml).query('.')) as B1
                Cross Apply x.nodes('x') AS B2(i)
             ) B

Returns

Name    RetSeq  RetVal
Josh    1       A2A-8292
Adam    1       D2C-1292
Adam    2       B2A-7292
Jery    1       A2A-1292
Jery    2       F2A-2292
Jery    3       C2A-2292

SQL 服务器 - 编写查询以规范化构造不当的模式中的逗号分隔值

SQL Server - write query that normalizes comma separated values in a poorly constructed schema

sql-server

sql-server-2012

database-normalization