获取地图 <Column,ValueOfTheColumn> 从SQL查询（C＃MVC5）

Question

I have a C# method that returns perfectly a sql string query (unknown columns + unknown table + unknown conditions).

How can I get a map as a result of executing the query ?

Thank you.

Edit

(copied from an OP's answer, which should not have been an answer by Shnugo)

Guys sorry if that is not clear enough, I mean having as a result : KeyValuePair<string, string>

• the first string is the column name or the alias,
• the second string is the value returned from the query

I don't know what is the table, the columns on SQL, it's a method that generate the query, I'm trying to build something dynamic.

I hope that's more clear.

Answer 1

With SQL Server you have two approaches

• sp_describe_first_result_set
• FOR XML RAW, XMLDATA or XMLSCHEMA

Try this

EXEC sp_describe_first_result_set N'SELECT * FROM sys.objects'; 

or

SELECT  TOP 0 * FROM sys.objects FOR XML RAW,XMLSCHEMA

or

SELECT  TOP 0 * FROM sys.objects FOR XML RAW,XMLDATA

UPDATE

Your edit told me, that you are trying to create a list of Key-Value-Pairs out of an unknown table / query result.

One approach is to create an XML result and use the XMLs great abilities to deal with generic structures:

In this case the unknown query is SELECT * FROM sys.objects . To be able to know, to which row a KVP belongs, there must be a RowKey :

SELECT r.value('@RowKey','nvarchar(max)') AS RowKey
      ,attr.value('local-name(.)','nvarchar(max)') AS ColumnName
      ,attr.value('.','nvarchar(max)') AS ColumnValue
FROM
(
SELECT 
    (
    SELECT o.object_id AS RowKey
           ,* 
    FROM sys.objects AS o 
    FOR XML RAW,TYPE
    ) 
) AS TableRows(InXML)
CROSS APPLY TableRows.InXML.nodes('/row') AS A(r)
CROSS APPLY A.r.nodes('@*') AS B(attr)

The (partial) result

Key ColumnName          ColumnValue
3   RowKey              3
3   name                sysrscols
3   object_id           3
3   schema_id           4
3   parent_object_id    0
3   type                S 
3   type_desc           SYSTEM_TABLE
[many more]

Warning

Whatever you are trying to achieve: KVP -solutions tend to become a severe headache... (type safety, castings, pivoting...)