The data reader is incompatible with the specified Entity Framework

Question

I have a method that will return the bare min results from a sproc to fill a select menu. When I want the bare min results I pass bool getMin = true to the sproc, and when I

Answer 1

I understand this is an old post; but, I wanted to share what I learned tonight about this. What I found that the 'most relevant portion of the error message is stating' is this.

db.proc_GetFramingSystems(brandID, frameType, glazeMethod, getMin).ToList<IFramingSystem>();

is expecting a column to be returned from the stored procedure with the alias of 'FrameType'.

I ran into this when I created a POCO (plain old clr object) class of my table with more programmer friendly names. Instead of a strongly typed name of say 'email_address', I wanted 'EmailAddy' and so forth. I created a mapped class stating this among other mapped columns.

this.Property(t => t.EmailAddy).HasColumnName("email_address");

Although this is necessary for other parts of EF to work, the mapping class is not referenced when executing a db.SqlQuery. So, when the code below executes

var a = new SqlParameter("@fshipno", shipno);
return _context.db.SqlQuery<EmailList>("exec spGetEmailAddy @fshipno", a).ToList();

It generated the same error except instead of 'FrameType', it mentioned 'EmailAddy'. The fix... I had to alias the 'email_address' column in my stored procedure to 'EmailAddy' to get it to map the returned dataset to my POCO.

EDIT: I have found that this only works if your method is returning an IEnumberable

public IEnumberable<myPOCO> GetMyPoco()

You will get the same error message if you are attempting to return a single POCO object.

public myPOCO GetMyPoco()

Answer 2

If you are inserting/deleting/updating (these are considered by EF as 'non-query'), and can be called by our code using

MyDbContext.Database.ExecuteSqlCommand(insert into Table (Col1,Col2) values (1,2));

But if are doing select query for a raw SQL statement, then use

MyDbContext.DbSet<Table_name>.SqlQuery(select * from table_name).ToList();

or

MyDbContext.Database.SqlQuery(select * from table_name).ToList();

()

The SqlQuery() function, in EF, for strange reasons, throw exception Insert/delete/update operation. (The exception thrown is "A member of the type, does not have a corresponding column in the data reader with the same name.") But it has actually performed operation if you open your Sql Management Studio and check for the entries.

FYI http://www.entityframeworktutorial.net/EntityFramework4.3/raw-sql-query-in-entity-framework.aspx

Answer 3

To me it seems that both branches of the IF return different data, the first branch returns 9 columns where the second - only three. I believe the EF can't reflect the IFramingSystem from the latter. Specifically, the column FrameType (and 5 other columns) are obviously missing:

 ...
 SELECT c.ID,c.Name,c.Descr    <- where are the remaining columns
    from Catelog.Component c
 ...