How convert Linq query to stored procedure

Question

Hi All,

     How we can below linq query convert in to  sql  stored procedure query?

  var output = (from c in db.candidates
                              select new
                              {
                                  c.ID,
                                  c.FirstName,
                                  c.LastName,
                                  c.LastClicked ,
                                  ProfessionName = c.Profession1.Name,
                                  SpecialtyName = c.Specialty1.Specialty1,
                                  c.Phone,
                                  c.Email,
                                  LastPageClicked = db.CandidateBlastListClicks.Where(l => l.CandidateBlastListId == c.ID).OrderByDescending(l => l.UTCDateTime).FirstOrDefault().URL.Replace("https://www.abc.com", "")
                              }).ToList();

Answer 1

To convert a LINQ query to a stored procedure, you'll need to manually create the stored procedure in your database and rewrite the query logic to fit the stored procedure syntax. Here are the general steps to follow:

Create the stored procedure: Use a database management tool (e.g., SQL Server Management Studio) to create a new stored procedure. Specify the input parameters, output parameters (if any), and the SQL logic that performs the desired query.

Rewrite the LINQ query logic: Analyze your LINQ query and rewrite it using SQL syntax within the stored procedure. This may involve translating LINQ operators, conditions, joins, and projections into SQL statements such as SELECT, FROM, WHERE, JOIN, and so on.

Map parameters: In the stored procedure, map the input parameters of the stored procedure to the corresponding SQL parameters. This allows you to pass values from your application to the stored procedure.

Execute the stored procedure: From your application code, invoke the stored procedure using the appropriate data access framework (e.g., ADO.NET) and pass the necessary parameters. Retrieve and process the results returned by the stored procedure, if any.

By following these steps, you can convert the logic of your LINQ query into a stored procedure that can be executed directly on the database server. Remember to handle any necessary error handling, security considerations, and performance optimizations as part of this process.

Answer 2

According to https://learn.microsoft.com/en-us/dotnet/framework/data/adonet/sql/linq/how-to-display-generated-sql, try adding db.Log = Console.Out and execute your current program. The SQL query that corresponds to your LINQ should appear in Output window of Visual Studio. You can use it to make a variant of the stored procedures.

If you are using Entity Framework, there are other techniques.

To view the SQL queries, it is also possible to use the SQL Server Profiler from Tools menu of Management Studio.

Answer 3

you don't give the navigation table names or keys, but it would be something like:

create proc GetCanidates
as
select 
 c.ID,
 c.FirstName,
 c.LastName,
 c.LastClicked ,
 p.Name as ProfessionName,
 s.Specialty1 as SpecialtyName,
 c.Phone,
 c.Email,
 LastPageClicked = 
 (
     select top 1 replace(URL.'https://www.abc.com','')
     from CandidateBlastListClicks
     where CandidateBlastListId == c.ID
     order by desc UTCDateTime
 )
from candidates c
join Profession p on p.Id = c.Profession1Id
join Specialty s on s.Id = c.Specialty1Id