Value Parameter for Entity Framework Stored Procedure Table

c# ef-code-first entity-framework stored-procedures table-valued-parameters

Question

I'm trying to call a stored procedure that accepts a table value parameter. I know that this isn't directly supported in Entity Framework yet but from what I understand you can do it using the ExecuteStoreQuery command off of the ObjectContext. I have a generic entity framework repository where I have the following ExecuteStoredProcedure method:

public IEnumerable<T> ExecuteStoredProcedure<T>(string procedureName, params object[] parameters)
{
    StringBuilder command = new StringBuilder();
    command.Append("EXEC ");
    command.Append(procedureName);
    command.Append(" ");

    // Add a placeholder for each parameter passed in
    for (int i = 0; i < parameters.Length; i++)
    {
        if (i > 0)
            command.Append(",");

        command.Append("{" + i + "}");
    }

    return this.context.ExecuteStoreQuery<T>(command.ToString(), parameters);
}

The command string ends up like this:

EXEC someStoredProcedureName {0},{1},{2},{3},{4},{5},{6},{7}

I tried to run this method on a stored procedure that accepts a table valued parameter and it breaks. I read here that the parameters needed to be of type SqlParameter and the table valued parameter needs to have the SqlDbType set to Structured. So I did this and I get an error stating:

The table type parameter p6 must have a valid type name

So, I set the SqlParameter.TypeName to the name of the user defined type I created on the database and then when I run the query I get the following truly helpful error:

Incorrect syntax near '0'.

I can get the query to run if I revert back to ADO.NET and and execute a data reader but I was hoping to get it to work using the data context.

Is there a way to pass a table value parameter using ExecuteStoreQuery? Also, I am actually using Entity Framework Code First and casting the DbContext to an ObjectContext to get the ExecuteStoreQuery method available. Is this necessary or can I do this against the DbContext as well?

1
65
10/23/2017 12:06:24 PM

Accepted Answer

UPDATE

I've added support for this on Nuget Package - https://github.com/Fodsuk/EntityFrameworkExtras#nuget (EF4,EF5,EF6)

Check out the GitHub repository for code examples.


Slightly off question, but none the less useful for people trying to pass user-defined tables into a stored procedure. After playing around with Nick's example and other Stackoverflow posts, I came up with this:

class Program
{
    static void Main(string[] args)
    {
        var entities = new NewBusinessEntities();

        var dt = new DataTable();
        dt.Columns.Add("WarningCode");
        dt.Columns.Add("StatusID");
        dt.Columns.Add("DecisionID");
        dt.Columns.Add("Criticality");

        dt.Rows.Add("EO01", 9, 4, 0);
        dt.Rows.Add("EO00", 9, 4, 0);
        dt.Rows.Add("EO02", 9, 4, 0);

        var caseId = new SqlParameter("caseid", SqlDbType.Int);
        caseId.Value = 1;

        var userId = new SqlParameter("userid", SqlDbType.UniqueIdentifier);
        userId.Value = Guid.Parse("846454D9-DE72-4EF4-ABE2-16EC3710EA0F");

        var warnings = new SqlParameter("warnings", SqlDbType.Structured);
        warnings.Value= dt;
        warnings.TypeName = "dbo.udt_Warnings";

        entities.ExecuteStoredProcedure("usp_RaiseWarnings_rs", userId, warnings, caseId);
    }
}

public static class ObjectContextExt
{
    public static void ExecuteStoredProcedure(this ObjectContext context, string storedProcName, params object[] parameters)
    {
        string command = "EXEC " + storedProcName + " @caseid, @userid, @warnings";

        context.ExecuteStoreCommand(command, parameters);
    }
}

and the stored procedure looks like this:

ALTER PROCEDURE [dbo].[usp_RaiseWarnings_rs]
    (@CaseID int, 
     @UserID uniqueidentifier = '846454D9-DE72-4EF4-ABE2-16EC3710EA0F', --Admin
     @Warnings dbo.udt_Warnings READONLY
)
AS

and the user-defined table looks like this:

CREATE TYPE [dbo].[udt_Warnings] AS TABLE(
    [WarningCode] [nvarchar](5) NULL,
    [StatusID] [int] NULL,
    [DecisionID] [int] NULL,
    [Criticality] [int] NULL DEFAULT ((0))
)

Constraints I found include:

  1. The parameters you pass into ExecuteStoreCommand have to be in order with the parameters in your stored procedure
  2. You have to pass every column in to your user-defined table, even if they are have defaults. So it seems i couldn't have a IDENTITY(1,1) NOT NULL column on my UDT
93
12/24/2016 9:37:48 AM

Popular Answer

Okay, so here is a 2018 update: end to end solution which describes how to invoke stored procedure with table parameter from Entity Framework without nuget packages

I'm using EF 6.xx, SQL Server 2012 and VS2017

1. Your Table Value prameter

Let's say you have a simple table type defined like this (just one column)

go
create type GuidList as table (Id uniqueidentifier)

2. Your Stored procedure

and a stored procedure with several parameters like:

go
create procedure GenerateInvoice
    @listIds GuidList readonly,
    @createdBy uniqueidentifier,
    @success int out,
    @errorMessage nvarchar(max) out
as
begin
    set nocount on;

    begin try
    begin tran;  

    -- 
    -- Your logic goes here, let's say a cursor or something:
    -- 
    -- declare gInvoiceCursor cursor forward_only read_only for
    -- 
    -- bla bla bla
    --
    --  if (@brokenRecords > 0)
    --  begin
    --      RAISERROR(@message,16,1);
    --  end
    -- 


    -- All good!
    -- Bonne chance mon ami!

    select @success = 1
    select @errorMessage = ''

    end try
    begin catch  
        --if something happens let's be notified
        if @@trancount > 0 
        begin
            rollback tran;  
        end

        declare @errmsg nvarchar(max)
        set @errmsg =       
            (select 'ErrorNumber: ' + cast(error_number() as nvarchar(50))+
            'ErrorSeverity: ' + cast(error_severity() as nvarchar(50))+
            'ErrorState: ' + cast(error_state() as nvarchar(50))+
            'ErrorProcedure: ' + cast(error_procedure() as nvarchar(50))+
            'ErrorLine: ' + cast(error_number() as nvarchar(50))+
            'error_message: ' + cast(error_message() as nvarchar(4000))
            )
        --save it if needed

        print @errmsg

        select @success = 0
        select @errorMessage = @message

        return;
    end catch;

    --at this point we can commit everything
    if @@trancount > 0 
    begin
        commit tran;  
    end

end
go

3. SQL Code to use this stored procedure

In SQL you would use something like that:

declare @p3 dbo.GuidList
insert into @p3 values('f811b88a-bfad-49d9-b9b9-6a1d1a01c1e5')
exec sp_executesql N'exec GenerateInvoice @listIds, @CreatedBy, @success',N'@listIds [dbo].[GuidList] READONLY,@CreatedBy uniqueidentifier',@listIds=@p3,@CreatedBy='FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF'

4. C# Code to use this stored procedure

And here is how you can call that Stored Procedure from Entity Framework (inside WebAPI):

    [HttpPost]
    [AuthorizeExtended(Roles = "User, Admin")]
    [Route("api/BillingToDo/GenerateInvoices")]
    public async Task<IHttpActionResult> GenerateInvoices(BillingToDoGenerateInvoice model)
    {
        try
        {
            using (var db = new YOUREntities())
            {
                //Build your record
                var tableSchema = new List<SqlMetaData>(1)
                {
                    new SqlMetaData("Id", SqlDbType.UniqueIdentifier)
                }.ToArray();

                //And a table as a list of those records
                var table = new List<SqlDataRecord>();

                for (int i = 0; i < model.elements.Count; i++)
                {
                    var tableRow = new SqlDataRecord(tableSchema);
                    tableRow.SetGuid(0, model.elements[i]);
                    table.Add(tableRow);
                }

                //Parameters for your query
                SqlParameter[] parameters =
                {
                    new SqlParameter
                    {
                        SqlDbType = SqlDbType.Structured,
                        Direction = ParameterDirection.Input,
                        ParameterName = "listIds",
                        TypeName = "[dbo].[GuidList]", //Don't forget this one!
                        Value = table
                    },
                    new SqlParameter
                    {
                        SqlDbType = SqlDbType.UniqueIdentifier,
                        Direction = ParameterDirection.Input,
                        ParameterName = "createdBy",
                        Value = CurrentUser.Id
                    },
                    new SqlParameter
                    {
                        SqlDbType = SqlDbType.Int,
                        Direction = ParameterDirection.Output, // output!
                        ParameterName = "success"
                    },
                    new SqlParameter
                    {
                        SqlDbType = SqlDbType.NVarChar,
                        Size = -1,                             // "-1" equals "max"
                        Direction = ParameterDirection.Output, // output too!
                        ParameterName = "errorMessage"
                    }
                };

                //Do not forget to use "DoNotEnsureTransaction" because if you don't EF will start it's own transaction for your SP.
                //In that case you don't need internal transaction in DB or you must detect it with @@trancount and/or XACT_STATE() and change your logic
                await db.Database.ExecuteSqlCommandAsync(TransactionalBehavior.DoNotEnsureTransaction,
                    "exec GenerateInvoice @listIds, @createdBy, @success out, @errorMessage out", parameters);

                //reading output values:
                int retValue;
                if (parameters[2].Value != null && Int32.TryParse(parameters[2].Value.ToString(), out retValue))
                {
                    if (retValue == 1)
                    {
                        return Ok("Invoice generated successfully");
                    }
                }

                string retErrorMessage = parameters[3].Value?.ToString();

                return BadRequest(String.IsNullOrEmpty(retErrorMessage) ? "Invoice was not generated" : retErrorMessage);
            }
        }
        catch (Exception e)
        {
            return BadRequest(e.Message);
        }
    }
}

I hope it helps! 🙂



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