How to convert a simple SQL to LINQ

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I have a simple SQL Query. I am learning LINQ. can anyone help to understand, how can i convert SQl query to LINQ

Select LDRSectionReference from LDR.LDRFlagName Where SectionID=
(Select TOP 1 SectionID from LDR.LDRFlagName Order by 1 desc)

this above query is giving me the reference number from the table where sectionID is max.

What I have tried:

I have no idea to try.
Its a simple SQL query which return the reference detail from the table where sectionID is maximum.

Posted 26-Feb-20 18:29pm

Member 9956700

Updated 26-Feb-20 20:29pm

v2

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Maciej Los · Answer 1 · 2020-02-26T20:30:00

Solution 1

Try this:

C#

var result = LDR.LDRFlagName
    .OrderByDescending(x=>x.SectionID)
    .Select(x->x.LDRSectionReference);

You can also use First()[^] or FirstOrDefault()[^] methods.

Posted 26-Feb-20 20:30pm

Maciej Los

Updated 26-Feb-20 20:54pm

v3

Comments

Member 9956700 27-Feb-20 2:45am

you meant..

var result = from LDRSectionReference in LDR.LDRFlagName
.OrderByDescending(x=>x.SectionID)
.Select(x->x.LDRSectionReference);

Maciej Los 27-Feb-20 2:53am

If you say so... You're the owner of data ;)

Richard Deeming 27-Feb-20 6:41am

That won't compile: CS0742 A query body must end with a select clause or a group clause

Remember that:

var result = from x in someQuery select x;

is identical to:

var result = someQuery;

Member 9956700 27-Feb-20 10:34am

how to resolve this error?
Example

var a = from ss in studentList
.OrderByDescending(x=>x.StudentID).Select(x=>x.StudentName)
select ss.FirstOrDefault();