如何使用 EF Core 从存储过程中获取返回值和 output 值？

Question

ALTER PROCEDURE [dbo].[SearchMovies]
    --@Year     int = null,
    @CategoryIds varchar(50) = null,
    @Keywords nvarchar(4000) = null,
    @PageIndex int = 1, 
    @PageSize int = 2147483644,
    @TotalRecords int = null OUTPUT
As ...

EF Repository:

 public class EFRepository<T> : IRepository<T> where T : BaseEntity
{
    private readonly ApplicationDbContext _ctx;
    private  DbSet<T> entities;
    string errorMessage = string.Empty;

    public EFRepository(ApplicationDbContext context)
    {
        this._ctx = context;
        entities = context.Set<T>();
    }     
   ...

    public IQueryable<T> ExecuteStoredProcedureList(string commandText, params object[] parameters)
    {          
        _ctx.Database.ExecuteSqlCommand(commandText, parameters);
        return entities.FromSql(commandText, parameters);
    }
}

I call this like:

var pCategoryIds = new SqlParameter()
            {
                ParameterName = "@CategoryIds",
                Value = commaSeparatedCategoryIds,
                DbType = DbType.String
            };
var pKeywords = new SqlParameter()
            {
                ParameterName = "@Keywords",
                DbType = DbType.String,
                Value = name
            };
var pPageIndex = new SqlParameter()
            {
                ParameterName = "@PageIndex",
                DbType = DbType.Int32,
                Value = pageIndex
            };
var pPageSize = new SqlParameter()
            {
                ParameterName = "@PageSize",
                DbType = DbType.Int32,
                Value = pageSize
            };

var pTotalRecords = new SqlParameter();
pTotalRecords.ParameterName = "@TotalRecords";
pTotalRecords.Direction = ParameterDirection.Output;
pTotalRecords.DbType = DbType.Int32;

var query1 = _ctx.Database.ExecuteSqlCommand("dbo.[SearchMovies] " +
                "@CategoryIds, @Keywords, @PageIndex, @PageSize, @TotalRecords OUTPUT", 
                pCategoryIds, pKeywords, pPageIndex, pPageSize, pTotalRecords);

var query2 = _ctx.Set<MovieItem>.FromSql("dbo.[SearchMovies] " +
                    "@CategoryIds, @Keywords, @PageIndex, @PageSize, @TotalRecords OUTPUT",
                    pCategoryIds, pKeywords, pPageIndex, pPageSize, pTotalRecords);

query1 does get the output pTotalRecords fine, but no return values, and the second query2 gets the return values but no output parameter.

In EF 6, we used to have SqlQuery to do both actions in one command, how can I do the same in EF core?

UPDATED :

Temporarily, I run 2 query, one to get the output param and one for result set.

 public IQueryable<T> ExecuteStoredProcedureList(string commandText, params object[] parameters)
    {          
        _ctx.Database.ExecuteSqlCommand(commandText, parameters);
        return entities.FromSql(commandText, parameters);
    }

Answer 1

I did something like this :-

-- My stored procedure:

CREATE PROCEDURE p1
AS
     BEGIN            
        RETURN 29
     END
GO

C# code

SqlParameter[] @params = 
{
   new SqlParameter("@returnVal", SqlDbType.Int) {Direction = ParameterDirection.Output}
 };   


_stagingContext.Database.ExecuteSqlCommand("exec @returnVal=" + storedProcName, @params);

var result = @params[0].Value; //result is 29 

Hope this helps

Answer 2

I am working to convert some EF6 code to EF Core, and ran into this same issue. In Microsoft.EntityFrameworkCore version 2.1.0 the following use of FromSql() does return a result set and set the output parameter. You have to use .ToList() to force the proc to execute immediately, thereby returning both the results and the output param.

This is a sample from my DbContext class:

private DbQuery<ExampleStoredProc_Result> ExampleStoredProc_Results { get; set; }
public IEnumerable<ExampleStoredProc_Result> RunExampleStoredProc(int firstId, out bool outputBit)
{
    var outputBitParameter = new SqlParameter
    {
        ParameterName = "outputBit",
        SqlDbType = SqlDbType.Bit,
        Direction = ParameterDirection.Output
    };

    SqlParameter[] parameters =
    {
        new SqlParameter("firstId", firstId),
        outputBitParameter
    };

    // Need to do a ToList to get the query to execute immediately 
    // so that we can get both the results and the output parameter.
    string sqlQuery = "Exec [ExampleStoredProc] @firstId, @outputBit OUTPUT";
    var results = ExampleStoredProc_Results.FromSql(sqlQuery, parameters).ToList();

    outputBit = outputBitParameter.Value as bool? ?? default(bool);

    return results;
}

The stored proc returns the following entity:

public class ExampleStoredProc_Result
{
    public int ID { get; set; }
    public string Name { get; set; }
}

Here's the stored proc:

CREATE PROCEDURE ExampleStoredProc 
    @firstId int = 0,
    @outputBit BIT OUTPUT
AS
BEGIN
    SET NOCOUNT ON;

    SET @outputBit = 1;

    SELECT @firstId AS [ID], 'first' AS [NAME]
    UNION ALL
    SELECT @firstId + 1 AS [ID], 'second' AS [NAME]
END
GO

Hopefully anyone that comes across this post in the future finds this useful.

Answer 3

var results = ExampleStoredProc_Results.FromSql(sqlQuery, parameters).ToList();

DbSet.FromSql Enables you to pass in a SQL command to be executed against the database to return instances of the type represented by the DbSet.

This answer will done the trick for me.

Answer 4

While trying to call a stored procedure with one input and one output parameter using ExecuteSqlCommandAsync EF Core. I was avoiding using FromSql on the entity object. Below code worked great from me so just wanted to share on this old post.

    SqlParameter Param1 = new SqlParameter();
    Param1 .ParameterName = "@Param1";
    Param1 .SqlDbType = SqlDbType.VarChar;
    Param1 .Direction = ParameterDirection.Input;
    Param1 .Size = 50;
    Param1 .Value = "ParamValue";

    SqlParameter Param2 = new SqlParameter();
    Param2 .ParameterName = "@Param2";
    Param2 .SqlDbType = SqlDbType.VarChar;
    Param2 .Size = 2048;
    Param2 .Direction = ParameterDirection.Output;

    var sprocResponse = await _dbContext.Database.ExecuteSqlCommandAsync("[dbo].[StoredProcName]  @Param1= @Param1, @Param2 = @Param2 OUTPUT", new object[] { Param1, Param2});
    string outPutVal= urlParam.Value.ToString();

Answer 5

Late response, but may be useful for someone:

My stored procedure:

create procedure GetSomething(@inCode varchar(5), @outValue int OUTPUT)
as
Set @outValue = 1
end

In C#,

SqlParameter[] parameters =
{
   new SqlParameter("@inCode", SqlDbType.Varchar { Direction = ParameterDirection.Input, Value = "InputValue" },
   new SqlParameter("@outValue", SqlDbType.Int { Direction = ParameterDirection.Output }
}
dbContext.Database.ExecuteSqlRaw("exec GetSomething @inCode, @outValue OUTPUT", parameters);
var result - parameters[1].Value;

The keyword OUTPUT is important while calling from .net

Answer 6

map into context as keyless entity

    modelBuilder
.Entity<yourentity>(
    eb =>
    {
        eb.HasNoKey();
        eb.ToView("procname");
    });

add a dbset

   public DbSet<yourentity> yourentity { get; set; }

exclude it from migrations

  modelBuilder.Entity<yourentity>().ToTable("procname", t => t.ExcludeFromMigrations());

then in context can execute it into the mapped type

var values = context.yourentity.FromSqlRaw("EXECUTE dbo.procname");