Question

我在ASP.NET MVC3应用程序中使用Entity Framework，我正在尝试使用以下代码：

var token = "";
this.Database.ExecuteSqlCommand("exec dbo.MyUsp", new SqlParameter("token", token));

我的存储过程签名是：

CREATE PROCEDURE MyUSP(@token varchar(10) OUT)
(...)

当我使用此代码时，我收到一条错误消息，指出参数“@token”是预期但未提供。

如何告诉EF令牌参数是否用于输出？

Answer 1

我最终使用它来使它工作，但我确信有更优化的方式：

var p = new SqlParameter
{
    ParameterName = "token",
    DbType = System.Data.DbType.String,
    Size = 100,
    Direction = System.Data.ParameterDirection.Output
};
var resp = this.Database.SqlQuery<String>("exec dbo.usp_GetRequestToken @token", p);

return resp.First();

Answer 2

var outParam = new SqlParameter();
outParam.ParameterName = "OutPutParametname";
outParam.SqlDbType = SqlDbType.Bit;//DataType Of OutPut Parameter
outParam.Direction = ParameterDirection.Output;
db.Database.ExecuteSqlCommand("EXEC ProcedureName @Param1,@Param2 OUTPUT", new SqlParameter("Param1", value), outParam);
object outParamValue = Convert.ToBoolean(outParam.Value);

Answer 3

您需要在参数中指明方向。例如，尝试这样的事情：

var p = new SqlParameter("token", token);
p.Direction = ParameterDirection.InputOutput;
this.Database.ExecuteSqlCommand("exec dbo.MyUsp", p);

Answer 4

我使用以下SQL和实体框架代码解决了这个问题

SP：

    ALTER PROCEDURE [dbo].[SaveSingleColumnValueFromGrid]
(
    @TableName VARCHAR(200),
    @ColumnName VARCHAR (200),
    @CompareField VARCHAR(200),
    @CompareValue VARCHAR(200),
    @NewValue VARCHAR(200),
    @Result INT OUTPUT
)
AS
BEGIN
    DECLARE @SqlString NVARCHAR(2000),
            @id INTEGER = 0;


    IF @CompareValue = ''
        BEGIN

            SET @SqlString = 'INSERT INTO ' + @TableName + ' ( ' + @ColumnName +  ' )  VALUES ( ''' + @NewValue + ''' ) ; SELECT @id = SCOPE_IDENTITY()';
            EXECUTE sp_executesql @SqlString, N'@id INTEGER OUTPUT',  @id OUTPUT
        END
    ELSE
        BEGIN
            SET @SqlString = 'UPDATE ' + @TableName + ' SET ' + @ColumnName +  ' = ''' + @NewValue + '''  WHERE ' + @CompareField +  ' = ''' + @CompareValue + '''';
            EXECUTE sp_executesql @SqlString
            set @id = @@ROWCOUNT
        END


    SELECT @Result = @id
END

实体框架代码：

public FieldUpdateResult SaveSingleColumnValueFromGrid(string tableName, string tableSetFieldName, string updatedValue, string tableCompareFieldName, string uniqueFieldValue)
        {

            var fieldUpdateResult = new FieldUpdateResult() ;
            var isNewRecord = false;

            if (string.IsNullOrWhiteSpace(uniqueFieldValue))
            {
                uniqueFieldValue = string.Empty;
                isNewRecord = true;
            }
            using (var dbContext = new DBEntities())
            {
                var resultParameter = new SqlParameter("@Result", SqlDbType.Int)
                {
                    Direction = ParameterDirection.Output
                };

                var recordsAffected = dbContext.Database.ExecuteSqlCommand("SaveSingleColumnValueFromGrid @TableName,@ColumnName,@CompareField,@CompareValue,@NewValue,@Result out",
                    new SqlParameter("@TableName", tableName),
                    new SqlParameter("@ColumnName", tableSetFieldName),
                    new SqlParameter("@CompareField", tableCompareFieldName),
                    new SqlParameter("@CompareValue", uniqueFieldValue),
                    new SqlParameter("@NewValue", updatedValue),
                    resultParameter);

                fieldUpdateResult.Success = recordsAffected > 0;
                if (isNewRecord)
                {
                    fieldUpdateResult.NewId = (int)resultParameter.Value;
                }
                else
                {
                    fieldUpdateResult.AffectedRows = (int)resultParameter.Value;
                }
            }

            return fieldUpdateResult;
        }

Answer 5

以下是我使用DevArt驱动程序为Oracle做的事情。我有一个名为P_SID.SID_PGet的package.proc，它返回一个字符串值。 proc是：

PROCEDURE SID_PGet(io_SID OUT varchar2) is
Begin
   io_SID:=GetSID; -- GetSID just goes off and gets the actual value
End;

下面是我如何调用它并检索SID值（我首先使用EF 4.1代码，这个方法在DbContext中）：

/// <summary>
/// Get the next SID value from the database
/// </summary>
/// <returns>String in X12345 format</returns>
public string GetNextSId()
{
    var parameter = new Devart.Data.Oracle.OracleParameter("io_SID", Devart.Data.Oracle.OracleDbType.VarChar, ParameterDirection.Output);
    this.Database.ExecuteSqlCommand("BEGIN P_SID.SID_PGet(:io_SID); END;", parameter);
    var sid = parameter.Value as string;

    return sid;
}

Answer 6

var db = new DBContext();
var outParam = new SqlParameter
{
    ParameterName = "@Param",
    DbType = System.Data.DbType.String,
    Size = 20,
    Direction = System.Data.ParameterDirection.Output
};
var r = db.Database.ExecuteSqlCommand("EXEC MyStoredProd @Param OUT",outParam );
Console.WriteLine(outParam.Value);

我看到每个人都缺少的主要部分是@Param之后需要的OUT关键字。

带输出参数的ExecuteSqlCommand

6 个答案: