Tsql 使用IndexOf和/或Substring将数据解析为单独的列

我正在为医院将数据从一个数据库迁移到另一个数据库。在旧数据库中，医生的专业ID都在一列（swvar_specialties）中，每个都用逗号分隔。在新数据库中，每个专业ID都有自己的列（例如：Specialty1_PrimaryID、Specialty2_PrimaryID、Specialty3_PrimaryID等）。我试图将数据从旧数据库中导出，并将其分离到这些单独的列中。我知道我可以使用

indexof

和

substring

来实现这一点-我只需要语法方面的帮助

所以这个查询：

Select swvar_specialties as Specialty1_PrimaryID
From PhysDirectory

可能会返回类似于39,52,16的结果。我需要此查询在结果中显示

Specialty1\u PrimaryID=39

，

Specialty2\u PrimaryID=52

，以及

Specialty3\u PrimaryID=16

。以下是我到目前为止的疑问。我最终将有一个连接从specialties表中提取专业名称。我只需要先解决这个问题

 Select pd.ref as PrimaryID, pd.swvar_name_first as FirstName, pd.swvar_name_middle as   MiddleName, 
 pd.swvar_name_last as LastName, pd.swvar_name_suffix + ' ' + pd.swvar_name_degree as NameSuffix, 
 pd.swvar_birthdate as DateOfBirth,pd.swvar_notes as AdditionalInformation, 'images/' + '' + pd.swvar_photo as ImageURL, 
 pd.swvar_philosophy as PhilosophyOfCare, pd.swvar_gender as Gender, pd.swvar_specialties as Specialty1_PrimaryID, pd.swvar_languages as Language1_Name 
 From PhysDirectory as pd

本文提供了有关如何使用split函数拆分逗号分隔字符串的一些详细信息

通过修改本文中提供的表值函数以提供标识列，我们可以针对特定行，例如Specialty1_PrimaryID：

/*
    Splits string into parts delimitered with specified character.
*/
CREATE FUNCTION [dbo].[SDF_SplitString]
(
    @sString nvarchar(2048),
    @cDelimiter nchar(1)
)
RETURNS @tParts TABLE (id bigint IDENTITY, part nvarchar(2048) )
AS
BEGIN
    if @sString is null return
    declare @iStart int,
        @iPos int
    if substring( @sString, 1, 1 ) = @cDelimiter 
    begin
        set @iStart = 2
        insert into @tParts
        values( null )
    end
    else 
        set @iStart = 1
        while 1=1
        begin
            set @iPos = charindex( @cDelimiter, @sString, @iStart )
            if @iPos = 0
            set @iPos = len( @sString )+1
            if @iPos - @iStart > 0          
            insert into @tParts
                values  ( substring( @sString, @iStart, @iPos-@iStart ))
            else
            insert into @tParts
                values( null )
            set @iStart = @iPos+1
            if @iStart > len( @sString ) 
            break
        end
    RETURN
END

您的查询可以使用此拆分功能，如下所示：

Select 
    pd.ref as PrimaryID, 
    pd.swvar_name_first as FirstName, 
    pd.swvar_name_middle as   MiddleName, 
    pd.swvar_name_last as LastName, 
    pd.swvar_name_suffix + ' ' + pd.swvar_name_degree as LastName, 
    pd.swvar_birthdate as DateOfBirth,pd.swvar_notes as AdditionalInformation,
    'images/' + '' + pd.swvar_photo as ImageURL, 
    pd.swvar_philosophy as PhilosophyOfCare, pd.swvar_gender as Gender, 
    (Select part from SDF_SplitString(pd.swvar_specialties, ',') where id=1) as Specialty1_PrimaryID, 
    (Select part from SDF_SplitString(pd.swvar_specialties, ',') where id=2) as Specialty2_PrimaryID,
    pd.swvar_languages as Language1_Name 
From PhysDirectory as pd

---

只有一条注释，但专业的多列不是第三种正常形式。应该有一张带有DrID、SpecialtId的桌子，这样Dr就可以没有或有很多特色菜了。