带VB6的SQL Server和ADO数据类型-从存储过程为VARCHAR（MAX）OUTPUT参数设置什么大小？

Question

Calling a stored procedure from VB6.

lcmdADOCommand.Parameters.Append lcmdADOCommand.CreateParameter("@p_user_id", adVarChar, adParamInput, 8, lobjFPSysUtilsSBO.ExtractUserFromToken(strSessionTokenVal))
          lcmdADOCommand.Parameters.Append lcmdADOCommand.CreateParameter("@p_source_data_XML", adVarChar, adParamInput, -1, strXML_Warranty_RSRef)
          lcmdADOCommand.Parameters.Append lcmdADOCommand.CreateParameter("@p_unlock_object_flag", adBoolean, adParamInput, , blnUnlockObjectVal)
          lcmdADOCommand.Parameters.Append lcmdADOCommand.CreateParameter("@p_return_data_flag", adBoolean, adParamInput, , True)

      Set lobjADOParam = lcmdADOCommand.CreateParameter("@p_output_record_XML", adVarChar, adParamOutput, -1, strXML_RecordList_RSRef)
      lobjADOParam.Size = 8000
      lcmdADOCommand.Parameters.Append lobjADOParam

With the last output parameter ... if I don't set the size to 8000 I get a runtime error

"Parameter object is improperly defined. Inconsistent or incomplete information was provided".

What is the maximum size I can use here in VB6 for an output of VARCHAR(MAX)? Setting the size to -1 on the input is fine but not on an Output Parameter

Answer 1

Use -1 for size of adLongVarChar or adLongVarWChar parameters, not adVarChar as in your snippet (missing a Long in the enum entry name).

Btw, it doesn't matter if direction in adParamInput or adParamOutput as your Q suggests, ie suggesting a problem w/ direction managed to only slow down finding answers here.