Linq tolist() count returns different value from translated sql

Question

I have a situation where the translated sql direct form Visual Studio is returning a different number of records from the Linq. I am expecting 4 items but in the count() of the resulting list I only have 1. This is the case despite creating more records - it always returns 1.

db.DCLVUnknowns.Where(x => x.DCLVUnknownId == Report.DCLid).ToList();

SELECT 
[Extent1].[DCLVUnknownId] AS [DCLVUnknownId], 
[Extent1].[Gender] AS [Gender], 
[Extent1].[Height] AS [Height], 
[Extent1].[Weight] AS [Weight],
[Extent1].[Age] AS [Age],
[Extent1].[Race] AS [Race],
[Extent1].[DCLid] AS [DCLid] 
FROM [dbo].[DCLVUnknown] AS [Extent1]

Strange thing is I have the same linq expression running fine for other entities and there is no problem. It is consistently happening at the same spot every time.

Answer 1

db.DCLVUnknowns

Is a query of the entire table, not the query for what you want.

If you want to inspect the IQueryable of the full query, try:

var results = db.DCLVUnknowns.Where(x => x.DCLVUnknownId == Report.DCLid);
var theResultSet = results.ToList();

Here results should translate as roughly:

SELECT 
[Extent1].[DCLVUnknownId] AS [DCLVUnknownId], 
[Extent1].[Gender] AS [Gender], 
[Extent1].[Height] AS [Height], 
[Extent1].[Weight] AS [Weight],
[Extent1].[Age] AS [Age],
[Extent1].[Race] AS [Race],
[Extent1].[DCLid] AS [DCLid] 
FROM [dbo].[DCLVUnknown] AS [Extent1]
WHERE [Extent1].[DCLVUnknownId] = DCLid

Assuming DCLVUnknownId is a PK/ Identity, you should see one result in theResultSet .