Get data with rfc-sdk language c

Question

Good morning all,
Me was given a task to develop a simple data read between C and SAP.  To foreshadow my prerequisites: I did not work with SAP and only have the possibilities of the NW7.01 Trial with a MaxDB database.
I will use the RFC_READ_TABLE and the RfcCallReceive function. The error handling and opening the rfchandle runs.
Using the RFC_READ_TABLE requires to fill the export parameters and handle the 3 tables, FIELDS, OPTIONS and DATA.
Handling the tables throws the error:
RFC Call/Exception: SYSTEM_FAILURE
Group       Error group 104
Key         RFC_ERROR_SYSTEM_FAILURE
Message     Incorrect field length for 'Remote Function Call'.
After searching here this problem I place 3 structs  to define the maximum length, which is returnd by the rfc:
typedef struct tDATA
{     SAP_CHAR     WA[512];
}tDATA;
typedef struct tFIELDS
{     SAP_CHAR     Fieldname[30];
     SAP_CHAR     Offset[6];
     SAP_CHAR     Length[6];
     SAP_CHAR     Type;
     SAP_CHAR     Fiedltext[60];
}tFIELDS;
typedef struct tOPTIONS
{     SAP_CHAR     WA[72];
}tOPTIONS;
Now using the size of these structs the error still stays the same.
So how do I initialise the tables and export parameters, to receive a useable data returned in the DATA table?
The declaration of the export and table structs is left out for now, I will post them immediatly if necessary.
Thanks & Regards
H.Fischer
Edited by: HFischer on Aug 12, 2009 4:09 PM

Answer 1

Hi all,
I returned to my mind that there was a function embedded in the SDK which generates a  headerfile which could be implemented easily. Now I have the structs necessary for the tables but the problem is still the same. I tried some configurations on the termination of the parameter list and I observe that the rfc does not handle with 5 export parameter tables. Here is the parameter declaration I try to use.
At last the tables are terminated with NULL, here I placed it at index 5 but with this the RFC throws an error about the RFC length mentioned in the first post. If I terminate at index 3 the "rfccallreceive" runs without error but returns two empty tables.
Or is it a problem in the declaration of ROWSKIPS and ROWCOUNT?
exporting[0].name = cU("QUERY_TABLE");
exporting[0].nlen = strlen(cU("QUERY_TABLE"));
exporting[0].addr = cU("SPFLI");
exporting[0].leng = strlen(cU("SPFLI"));
exporting[0].type = RFCTYPE_CHAR;
exporting[1].name = cU("DELIMITER");
exporting[1].nlen = strlen(cU("DELIMITER"));
exporting[1].addr = cU(" ");
exporting[1].leng = strlen(cU(" "));
exporting[1].type = RFCTYPE_CHAR;
exporting[2].name = cU("NO_DATA");
exporting[2].nlen = strlen(cU("NO_DATA"));
exporting[2].addr = cU(" ");
exporting[2].leng = strlen(cU(" "));
exporting[2].type = RFCTYPE_CHAR;
exporting[3].name = cU("ROWSKIPS");
exporting[3].nlen = strlen(cU("ROWSKIPS"));
exporting[3].addr = cU("0");
exporting[3].leng = strlen(cU("0"));
exporting[3].type = RFCTYPE_CHAR;
exporting[4].name = cU("ROWCOUNT");
exporting[4].nlen = strlen(cU("ROWCOUNT"));
exporting[4].addr = cU("0");
exporting[4].leng = strlen(cU("0"));
exporting[4].type = RFCTYPE_CHAR;
exporting[5].name = NULL; /*position I mean*/
importing[0].name = NULL;
tables[3].name = NULL;