Talvez um pouco mais de SQL dinâmico faça o truque (junto com um analisador)
Declare @String varchar(max) = '1,25,659'
Declare @SQL varchar(max) = ''
Select @SQL = @SQL + concat('Exec [dbo].[sp1] ',Key_Value,';',char(13))
From (Select * from [dbo].[udf-Str-Parse-8K](@String,',')) A
Select @SQL
--Exec(@SQL)
Devoluções
Exec [dbo].[sp1] 1;
Exec [dbo].[sp1] 25;
Exec [dbo].[sp1] 659;
O UDF, se necessário (super rápido!)
CREATE FUNCTION [dbo].[udf-Str-Parse-8K](@String varchar(8000), @Delimiter varchar(50))
Returns Table
As
--Usage: Select * from [dbo].[udf-Str-Parse-8K]('Dog,Cat,House,Car',',')
-- Select * from [dbo].[udf-Str-Parse-8K]('John||Cappelletti||was||here','||')
-- Select * from [dbo].[udf-Str-Parse-8K]('The quick brown fox',' ')
Return (
with cte1(N) As (Select 1 From (Values(1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) N(N)),
cte2(N) As (Select Top (IsNull(DataLength(@String),0)) Row_Number() over (Order By (Select NULL)) From (Select N=1 From cte1 a, cte1 b, cte1 c, cte1 d) A ),
cte3(N) As (Select 1 Union All Select t.N+DataLength(@Delimiter) From cte2 t Where Substring(@String,t.N,DataLength(@Delimiter)) = @Delimiter),
cte4(N,L) As (Select S.N,IsNull(NullIf(CharIndex(@Delimiter,@String,s.N),0)-S.N,8000) From cte3 S)
Select Key_PS = Row_Number() over (Order By A.N)
,Key_Value = Substring(@String, A.N, A.L)
,Key_Pos = A.N
From cte4 A
)