过程或函数 'x' 需要参数“@y”,这在 C# 上不是 supplied.Got 错误?

Procedure or function 'x' expects parameter '@y', which was not supplied.Got error on c#?

首先,我知道像这样的问题是重复的但是,请注意这个问题。 这是我的 C# 代码,它引发错误为:

Procedure or function 'aaa' expects parameter '@bbb', which was not supplied.

if (Dt.Rows.Count > 0)
{
    Cmd = new SqlCommand();
    Cmd.CommandText = ("[dbo].[aaa]");
    Cmd.CommandType = CommandType.StoredProcedure;
    Cmd.Parameters.Add("@bbb", SqlDbType.Int).Value = 1;
    Cmd.Parameters.Add("@LettType", SqlDbType.VarChar, 3).Value = LetterType;
    Cmd.Parameters.Add("@IsTajamo", SqlDbType.Char, 1).Value = 1;
    Da = new SqlDataAdapter(Cmd.CommandText, Con);
    Dt.Clear();
    /*Line72:*/    
    Da.Fill(Dt);
}

从技术上讲,我找不到错误在哪里。我传递了所有参数。当我在 MS-SQL 中单独执行我的存储过程时,它可以正确使用这些值。

各位专家能帮我解决这个问题吗? 注意:这里是存储过程:

   ALTER PROCEDURE [dbo].[aaa] (@bbb Int , @LettType CHAR(3) , @IsTajamo CHAR(1))

AS
BEGIN

select 1


END

注意:(可能会有帮助,这是我的堆栈跟踪):

at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action1 wrapCloseInAction) at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action1 wrapCloseInAction) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) at System.Data.SqlClient.SqlDataReader.TryConsumeMetaData() at System.Data.SqlClient.SqlDataReader.get_MetaData() at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString, Boolean isInternal, Boolean forDescribeParameterEncryption) at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite, Boolean inRetry, SqlDataReader ds, Boolean describeParameterEncryptionRequest) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean& usedCache, Boolean asyncWrite, Boolean inRetry) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method) at System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior) at System.Data.Common.DbCommand.System.Data.IDbCommand.ExecuteReader(CommandBehavior behavior) at System.Data.Common.DbDataAdapter.FillInternal(DataSet dataset, DataTable[] datatables, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior) at System.Data.Common.DbDataAdapter.Fill(DataTable[] dataTables, Int32 startRecord, Int32 maxRecords, IDbCommand command, CommandBehavior behavior) at System.Data.Common.DbDataAdapter.Fill(DataTable dataTable) at WebService.Services.GetLettersList(String UserName, String PassPhrase, String CodeName, String LetterType) in D:\Amiri\WebService\WebService\Services.asmx.cs:line 79

在你的行中:

Da = new SqlDataAdapter(Cmd.CommandText, Con);

您只传递了过程的名称,而忽略了参数。仅传递 Cmd(并将该连接添加到命令)以使用您定义的参数。

@Hans Kesting 说得对,但我觉得解释得不好。这是怎么回事...

da = new SqlDataAdapter(Cmd.CommandText, Con);

...您是否正在隐式创建一个与 Cmd 具有相同 CommandText 的新 SqlCommand。这与您直接使用 [dbo].[aaa] 作为参数值是一样的。因此,这个新 SqlCommand 没有分配 SqlParameters。然后你可以这样做:SqlDataAdapter.SelectCommand.Parameters.Add(....,但那是一团糟。

您需要做的是使用 SqlCommand (Cmd) 本身。但您还必须确保它已绑定到连接:

   Cmd = Con.CreateCommand(); //This hooks up the connection to this command
   Cmd.CommandText = "[dbo].[aaa]";
   Cmd.CommandType = CommandType.StoredProcedure;
   Cmd.Parameters.Add("@bbb", SqlDbType.Int).Value = 1;
   Cmd.Parameters.Add("@LettType", SqlDbType.VarChar, 3).Value = LetterType;
   Cmd.Parameters.Add("@IsTajamo", SqlDbType.Char, 1).Value = 1;
   Da = new SqlDataAdapter(Cmd); //Just the command
   Dt.Clear();
   Da.Fill(Dt);