实体框架存储过程

Question

I am building an Excel import feature that allows the user to specify which columns map to which property of the object. Then using reflection, I create a new object, set the property values and insert the new object into the DbSet. However, some of the new objects may be duplicates and should update an existing record instead of being added to the DbSet as a new object.

The Excel sheet will not contain a column for the object's ID. So I'm wanting to add an Index for a combination of other fields (such as FirstName and LastName). I want to then pass in a list of objects to the stored procedure like passing in a table parameter; so I can select all the records from the database where the indexes match.

How can I pass in a list of objects into an Entity Framework stored procedure?

Answer 1

DbSet is already a list objects to which you can add objects. If you have a functional key that uniquely identifies each object, then you should be able to find and update it using LINQ.

Answer 2

You can pass them through a comma separated list (string), as long as it's less than 8K characters. Then you can split them through this function. (The function would be used in the SP).

CREATE PROCEDURE ...
@NameList Varchar(8000)

Select * from People 
where (FirstName+'-'+LastName) in dbo.Split(@NameList,',')
....

The function to split values base on a delimiter chararter

CREATE FUNCTION [dbo].[Split]
(
    @Input VARCHAR(8000),
    @Delimiter CHAR(1)
)
RETURNS TABLE
AS
RETURN
(
    WITH Split(stpos,endpos)
    AS(
        SELECT 0 AS stpos, CHARINDEX(@Delimiter,@Input) AS endpos
        UNION ALL
        SELECT endpos+1, CHARINDEX(@Delimiter,@Input,endpos+1)
            FROM Split
            WHERE endpos > 0
    )
    SELECT  SUBSTRING(@Input,stpos,COALESCE(NULLIF(endpos,0),LEN(@Input)+1)-stpos) As Item
    FROM Split
)