使用 Azure 移动自定义 API 从存储过程输出

Question

我有一个存储过程，它向表中添加一个新条目并将 ID（作为 nvarchar(255)）输出到 @NewID。我可以使用 Postman 对 asp.net 后端执行该过程，但我无法获得输出...我有几个存储过程，它们都工作得很好，只是弄清楚如何在 C# Post 方法中捕获输出.

为了澄清，我正在尝试执行存储过程并使用实体框架通过 Web 服务捕获输出。这是在 Azure 移动服务 asp.net 服务器上运行的。

测试存储过程

ALTER PROCEDURE [dbo].[AddEnclosureKey]
(
    -- Add the parameters for the stored procedure here
    @SpecItemID nvarchar(255),
    @EnclosureType varchar(3) = 'XXX',
    @Comments varchar(50),
    @Elevation varchar(50),
    @ProvidedBy varchar(50),
    @InstalledBy varchar(50),
    @SiteID nvarchar(255) = 'CE359D6F-490B-45E4-BA14-72D20AB757FD',
    @NewID nvarchar(255) OUTPUT
)
AS
IF (@SpecItemID is not null or @SiteID is not null)
    BEGIN

        -- SET NOCOUNT ON added to prevent extra result sets from
        -- interfering with SELECT statements.
        SET NOCOUNT ON;

        -- insert
        INSERT INTO dbo.SiteEnclosureKey(EnclosureKeyComments,EnclosureKeyType, EnclosureKeyElevation,EnclosureKeyProvidedBy,EnclosureKeyInstalledBy,EnclosureKeyItemID,EnclosureKeySiteID)
        VALUES (@Comments,IIF(@EnclosureType = 'XXX',dbo.AutoEnclosureKeyType(@SpecItemID),@EnclosureType), @Elevation, @ProvidedBy, @InstalledBy,@SpecItemID,@SiteID);

        IF @@IDENTITY > 0
        SELECT @NewID = Id FROM dbo.SiteEnclosures WHERE EnclosureID = @@IDENTITY;
        ELSE
        SET @NewID = null

    END
ELSE
    BEGIN
        RETURN 0
    END

自定义 ApiController

   [MobileAppController]
        public class AddEnclosureKeyController : ApiController
        {
            // POST api
            [HttpPost, Route("api/addenclosurekey")]
            public string Post(string item, string type="XXX", string comments="", string elevation="", string providedby="", string installedby="", string site="CE359D6F-490B-45E4-BA14-72D20AB757FD")
            {
                using (MIIToolsContext context = new MIIToolsContext())
                {
                    //get the database from the context
                    var database = context.Database;

                    //create the sql statement
                    var param1 = new System.Data.SqlClient.SqlParameter("@SpecItemID", item);
                    var param2 = new System.Data.SqlClient.SqlParameter("@EnclosureType", type);
                    var param3 = new System.Data.SqlClient.SqlParameter("@Comments", comments);
                    var param4 = new System.Data.SqlClient.SqlParameter("@Elevation", elevation);
                    var param5 = new System.Data.SqlClient.SqlParameter("@ProvidedBy", providedby);
                    var param6 = new System.Data.SqlClient.SqlParameter("@InstalledBy", installedby);
                    var param7 = new System.Data.SqlClient.SqlParameter("@SiteID", site);
                    var param8 = new System.Data.SqlClient.SqlParameter()
                    {
                        ParameterName = "@NewID",
                        Direction = System.Data.ParameterDirection.Output,
                        SqlDbType = System.Data.SqlDbType.NVarChar,
                        Size = 255
                    };

                    //var result = database.SqlQuery<string>("dbo.AddEnclosureKey @SpecItemID , @EnclosureType , @Comments , @Elevation , @ProvidedBy , @InstalledBy , @SiteID , @NewID OUTPUT", param1, param2, param3, param4, param5, param6, param7, param8);

                    //return NewID.ToString();

                   database.ExecuteSqlCommand("EXEC dbo.AddEnclosureKey @SpecItemID , @EnclosureType , @Comments , @Elevation , @ProvidedBy , @InstalledBy , @SiteID , @NewID OUTPUT", param1, param2, param3, param4, param5, param6, param7, param8);


                    return (string)param8.Value ?? "boo";

                }
            }
        }

Answer 1

将OUTPUT 关键字添加到您的执行行中，就在@NewID 部分之后，它将起作用：

database.ExecuteSqlCommand("EXEC dbo.AddEnclosureKey @SpecItemID , @EnclosureType , @Comments , @Elevation , @ProvidedBy , @InstalledBy , @SiteID , @NewID OUTPUT", 
                            param1, param2, param3, param4, param5, param6, param7, param8);

但正如我在 cmets 中提到的，您与代码有很大关系。您永远不应该在操作中触及数据库——您需要一个数据访问层。您最好不要在使用 ORM 时直接调用过程。您最好在您的过程中将SELECT 部分更改为SET (SET @param = (SELECT some FROM some blah blah blah))，依此类推。但它们与问题无关。 OUTPUT 关键字将完成这项工作。

Answer 2

想通了... SQL SP 参数似乎不是 INPUT 或 OUTPUT 而是 INPUT/OUTPUT。 所以我改变了 Direction = System.Data.ParameterDirection.InputOutput，它现在可以工作了。