Question

我有一个包含以下条目的列的表 -

Drug
Sertraline 100mg tablets
Phenobarbitol 20mg capsules

我希望将此列拆分为四列 -

Drugname    Strength   Units   Form
Sertraline  100        mg      tablets

有人可以指导我这是谁做的吗？

Answer 1

使用一点XML和CROSS APPLY

模式清晰，易于扩展或根据需要收缩

示例

Select A.* ,B.* From YourTable A Cross Apply ( Select Pos1 = ltrim(rtrim(xDim.value('/x[1]','varchar(max)'))) ,Pos2 = ltrim(rtrim(xDim.value('/x[2]','varchar(max)'))) ,Pos3 = ltrim(rtrim(xDim.value('/x[3]','varchar(max)'))) ,Pos4 = ltrim(rtrim(xDim.value('/x[4]','varchar(max)'))) ,Pos5 = ltrim(rtrim(xDim.value('/x[5]','varchar(max)'))) From (Select Cast('<x>' + replace((Select replace(A.[Drug],' ','§§Split§§') as [*] For XML Path('')),'§§Split§§','</x><x>')+'</x>' as xml) as xDim) as B1 ) B

<强>返回

Pos1 Pos2 Pos3 Pos4 Pos5 Sertraline 100mg tablets NULL NULL Phenobarbitol 20mg capsules NULL NULL

Answer 2

还有一个建议：

第一个CTE将您的CSV字符串转换为XML，允许分别处理每个部分第二个CTE检索这三个部分最后的SELECT使用一些字符串方法来分隔力量和单位。

DECLARE @tbl TABLE(Drug VARCHAR(100));
INSERT INTO @tbl VALUES('Sertraline 100mg tablets')
                      ,('Phenobarbitol 20mg capsules');
WITH Splitted AS
(
    SELECT CAST('<x>' + REPLACE((SELECT Drug AS [*] FOR XML PATH('')),' ','</x><x>') + '</x>' AS XML) AS Casted
    FROM @tbl 
)
,Parts AS
(
    SELECT Casted.value('/x[1]/text()[1]','nvarchar(100)') AS Drugname
          ,Casted.value('/x[2]/text()[1]','nvarchar(100)') AS CombinedStrenthUnit
          ,Casted.value('/x[3]/text()[1]','nvarchar(100)') AS Form
    FROM Splitted
)
SELECT *
      ,LEFT(CombinedStrenthUnit,PATINDEX('%[a-zA-Z]%',CombinedStrenthUnit)-1) AS Strength 
      ,SUBSTRING(CombinedStrenthUnit,PATINDEX('%[a-zA-Z]%',CombinedStrenthUnit),1000) AS Unit
FROM Parts;

结果

Drugname        S&U     Form        Strength    Unit
Sertraline      100mg   tablets     100         mg
Phenobarbitol   20mg    capsules    20          mg

Answer 3

我使用user-defined split function将文本拆分成3个由空格字符分隔的部分，如下所示

当然，如果你有SQL Server 2016或更高版本，那么你也可以使用STRING_SPLIT SQL函数

with rawdata as (
    select rn = ROW_NUMBER() over (order by txt), * from drugs
), cte as (
select
    rn,
    d.txt,
    s.id,
    s.val
from rawdata d
cross apply dbo.Split(rtrim(ltrim(d.txt)),' ') s
)
select * from cte

请注意，需要Row_Number列来标识以下脚本中的每一行。如果源表中有PK字段，而不是使用Row_Number函数创建的字段，则可以直接使用这些主键字段

为了拆分第二列（强度和单位），我再次使用自定义SQL函数; ClearNumericCharacters和ClearNonNumericCharacters 当然，您可以使用内联函数或RegExp而不是UDF

这是最终的SQL CTE表达式

with rawdata as (
    select rn = ROW_NUMBER() over (order by txt), * from drugs
), cte as (
select
    rn,
    d.txt,
    s.id,
    s.val
from rawdata d
cross apply dbo.Split(rtrim(ltrim(d.txt)),' ') s
), cte2 as (
select
rn,
case when id = 1 then val end as Drugname,
case when id = 2 then dbo.ClearNonNumericCharacters(val) end as Strength,
case when id = 2 then dbo.ClearNumericCharacters(val) end as Units,
case when id = 3 then val end as Form
from cte
)
select
    max(Drugname) Drugname,
    max(Strength) Strength,
    max(Units) Units,
    max(Form) Form
from cte2
group by rn

输出

如何将Microsoft SQL Server中的字段拆分为多个列

3 个答案: