sql-server - 如何从分隔字符串创建多个列

Question

我有一个包含 4 个组件的库存字段，每个组件用“-”分隔。我不确定如何使用charindex来解析字符串，以便为分隔符之间找到的每个值返回一列。例如：字段值或字符串 = item-color-size-shape。

我的目标是最终得到一个项目作为列，颜色作为列，大小作为列，最后是形状。

Answer 1

如果它是最多 4 列，你可以这样尝试：

declare @Table table (SomeColumn varchar(100));
insert into @Table
    select 'ball-blue-small-round'  union all
    select 'ball-red-small-round'   union all
    select 'ball-green-small-round' union all
    select 'ball---square'          union all
    select '----';

;with stage (s)
as  (   select  replace(SomeColumn, '-', '.')
        from    @Table
    )
select  [item] = parsename(s,4),
        [color] = parsename(s,3),
        [size] = parsename(s,2),
        [shape] = parsename(s,1)
from    stage;

如果它 > 4 请回复，我们可以制定更动态的解决方案。

Answer 2

使用 CROSS APPLYs（使用冗长的名称来理解） -

declare @Table table (SomeColumn varchar(100));
insert into @Table
select 'ball-Orange-small-round'  union all
select 'bat-blue-medium-square'   union all
select 'stumps-green-large-rectangle'

SELECT * FROM @Table

SELECT Sub1.FirstSub1 AS Item
       ,Sub2.SecondSub1 AS Color
       ,Sub3.ThirdSub1 AS Size
       ,SubAfterThirdHyphen AS Shape 

FROM @Table 
CROSS APPLY (SELECT CHARINDEX('-',SomeColumn) AS FirstHyphenPos) AS Pos1
CROSS APPLY (SELECT SUBSTRING(SomeColumn,1,FirstHyphenPos-1) AS FirstSub1) AS Sub1
CROSS APPLY (SELECT SUBSTRING(SomeColumn,FirstHyphenPos+1,LEN(SomeColumn)) AS SubAfterFirstHyphen) AS Substr1

CROSS APPLY (SELECT CHARINDEX('-',Substr1.SubAfterFirstHyphen) AS SecondHyphenPos) AS Pos2
CROSS APPLY (SELECT SUBSTRING(Substr1.SubAfterFirstHyphen,1,SecondHyphenPos-1) AS SecondSub1) AS Sub2
CROSS APPLY (SELECT SUBSTRING(Substr1.SubAfterFirstHyphen,SecondHyphenPos+1,LEN(Substr1.SubAfterFirstHyphen)) AS SubAfterSecondHyphen) AS Substr2

CROSS APPLY (SELECT CHARINDEX('-',Substr2.SubAfterSecondHyphen) AS ThirdHyphenPos) AS Pos3
CROSS APPLY (SELECT SUBSTRING(Substr2.SubAfterSecondHyphen,1,ThirdHyphenPos-1) AS ThirdSub1) AS Sub3
CROSS APPLY (SELECT SUBSTRING(Substr2.SubAfterSecondHyphen,ThirdHyphenPos+1,LEN(Substr2.SubAfterSecondHyphen)) AS SubAfterThirdHyphen) AS Substr3