The is an example of a C table operator that uses FNC_TblOpGetBaseInfo() to retrieve UDT metadata.
/* CREATE FUNCTION mift1() RETURNS TABLE VARYING USING FUNCTION mift1_contract SPECIFIC mift1 LANGUAGE C NO SQL NO EXTERNAL DATA PARAMETER STYLE SQLTable NOT DETERMINISTIC CALLED ON NULL INPUT EXTERNAL NAME 'CS!mift1!mift1.c!F!mift1'; */
#define SQL_TEXT Latin_Text #include <stdio.h> #include <sqltypes_td.h> #define BufferSize (32*1024) #define SetError(e, m) strcpy((char *)sqlstate, ( e) ); strcpy((char *)error_message, ( m ))
typedef struct
{
int colcount;
FNC_TblOpColumnDef_t *iCols;
FNC_TblOpHandle_t *Handle;
int is_eof;
int dimension;
}InputInfo_t;
int mift1_contract(
INTEGER *Result,
int *indicator_Result,
char sqlstate[6],
SQL_TEXT extname[129],
SQL_TEXT specific_name[129],
SQL_TEXT error_message[257])
{
FNC_TblOpColumnDef_t *oCols;
FNC_TblOpColumnDef_t *iCols;
Stream_Fmt_en format;
InputInfo_t *icolinfo;
int incount, outcount, ocolcount;
int i,j, totalcols;
UDT_BaseInfo_t *baseInfos;
char mycontract[] = "this is my contract... this is my contract... this is my contract...";
FNC_TblOpGetStreamCount(&incount, &outcount);
if(incount == 0)
{
SetError("U0003", "mift1 requires number of input streams to be > 0.");
return -1;
}
icolinfo = FNC_malloc (incount * sizeof(InputInfo_t));
totalcols = 0;
for(i=0; i < incount; i++)
{
icolinfo[i].colcount = FNC_TblOpGetColCount(i, ISINPUT);
totalcols += icolinfo[i].colcount;
icolinfo[i].iCols = FNC_malloc(TblOpSIZECOLDEF(icolinfo[i].colcount));
TblOpINITCOLDEF(icolinfo[i].iCols, icolinfo[i].colcount);
FNC_TblOpGetColDef(i, ISINPUT, icolinfo[i].iCols);
}
/* Allocate space for columns. */
oCols = (FNC_TblOpColumnDef_t *)FNC_malloc( TblOpSIZECOLDEF(totalcols) );
memset(oCols, 0 , TblOpSIZECOLDEF(totalcols) );
oCols->num_columns = totalcols;
oCols->length = TblOpSIZECOLDEF(totalcols) - (2 * sizeof(int)) ;
TblOpINITCOLDEF(oCols, totalcols);
ocolcount = 0;
/* Copy input columns to output columns. */
for(j=0; j < incount; j++)
{
iCols = icolinfo[j].iCols;
baseInfos = (UDT_BaseInfo_t *)FNC_malloc(iCols->num_columns * sizeof(UDT_BaseInfo_t));
/* Get base info */
FNC_TblOpGetBaseInfo(iCols, baseInfos);
for(i=0;i < iCols->num_columns;i++)
{
switch (iCols->column_types[i].datatype)
{
case DECIMAL1_DT:
case DECIMAL4_DT:
case DECIMAL8_DT:
oCols->column_types[ocolcount].size.range.totaldigit
= iCols->column_types[i].size.range.totaldigit;
oCols->column_types[ocolcount].size.range.fracdigit
= iCols->column_types[i].size.range.fracdigit;
break;
case DECIMAL2_DT:
oCols->column_types[ocolcount].size.range.totaldigit= 5;
oCols->column_types[ocolcount].size.range.fracdigit=
iCols->column_types[i].size.range.fracdigit;
break;
case TIME_DT:
case TIMESTAMP_DT:
case PERIOD_DT:
oCols->column_types[ocolcount].size.precision =
iCols->column_types[i].size.precision;
break;
case INTERVAL_YEAR_DT:
case INTERVAL_YTM_DT:
case INTERVAL_MONTH_DT:
case INTERVAL_DAY_DT:
case INTERVAL_DTH_DT:
case INTERVAL_DTM_DT:
case INTERVAL_DTS_DT:
case INTERVAL_HOUR_DT:
case INTERVAL_HTM_DT:
case INTERVAL_HTS_DT:
case INTERVAL_MINUTE_DT:
case INTERVAL_MTS_DT:
case INTERVAL_SECOND_DT:
oCols->column_types[ocolcount].size.intervalrange =
iCols->column_types[i].size.intervalrange;
break;
case JSON_DT:
oCols->column_types[ocolcount].JSONStorageFormat = JSON_TEXT_EN;
oCols->column_types[ocolcount].charset =
iCols->column_types[i].charset;
oCols->column_types[ocolcount].size.length =
iCols->column_types[i].size.length;
oCols->column_types[ocolcount].udt_indicator = 5;
memcpy(oCols->column_types[ocolcount].udt_type,
icols->column_types[i].udt_type, FNC_MAXNAMELEN_EON);
break;
case ARRAY_DT:
oCols->column_types[ocolcount].charset =
iCols->column_types[i].charset;
oCols->column_types[ocolcount].size.length =
iCols->column_types[i].size.length;
oCols->column_types[ocolcount].udt_indicator = 4;
memcpy(oCols->column_types[ocolcount].udt_type,
icols->column_types[i].udt_type, FNC_MAXNAMELEN_EON);
oCols->column_types[ocolcount].struct_num_attributes=
iCols->column_types[i].struct_num_attributes;
break;
default:
oCols->column_types[ocolcount].size.length =
iCols->column_types[i].size.length;
oCols->column_types[ocolcount].charset = LATIN_CT;
break;
}
oCols->column_types[ocolcount].datatype =
iCols->column_types[i].datatype;
oCols->column_types[ocolcount].period_et =
iCols->column_types[i].period_et;
oCols->column_types[ocolcount].bytesize =
iCols->column_types[i].bytesize;
ocolcount++;
}
FNC_free(baseInfos);
}
FNC_TblOpSetContractDef(mycontract, strlen(mycontract)+1);
/* Define output columns. */
FNC_TblOpSetOutputColDef(0, oCols);
format = INDICFMT1;
FNC_TblOpSetFormat("RECFMT", 0, ISINPUT, &format, sizeof(format));
FNC_TblOpSetFormat("RECFMT", 0, ISOUTPUT, &format, sizeof(format));
FNC_free(oCols);
for(i=0; i < incount; i++)
FNC_free(icolinfo[i].iCols);
FNC_free(icolinfo);
*Result = 1;
}
void mift1()
{
int i;
FNC_TblOpColumnDef_t *iCols, *oCols;
FNC_TblOpHandle_t *Handle,*OutHandle;
Stream_Fmt_en format;
int incount, outcount,j;
InputInfo_t *icolinfo;
int *Result;
int allStreamsEOF = 0;
LOB_CONTEXT_ID lobid;
FNC_LobLength_t actlen;
LOB_RESULT_LOCATOR lrl_a[32];
int truncerr;
BYTE Buffer[BufferSize];
int foundrow = 0;
int isfirsttime = 1;
FNC_TblOpGetStreamCount(&incount, &outcount);
icolinfo = FNC_malloc (incount * sizeof(InputInfo_t));
for(i=0; i < incount; i++)
{
/* Get Column Count */
icolinfo[i].colcount = FNC_TblOpGetColCount(i, ISINPUT);
/* Get Column Definitions */
icolinfo[i].iCols = FNC_malloc(TblOpSIZECOLDEF(icolinfo[i].colcount));
TblOpINITCOLDEF(icolinfo[i].iCols, icolinfo[i].colcount);
FNC_TblOpGetColDef(i, ISINPUT, icolinfo[i].iCols);
/* Get Handles */
icolinfo[i].Handle = (FNC_TblOpHandle_t *)FNC_TblOpOpen(i,'r',0);
icolinfo[i].dimension = FNC_TblOpIsDimension(i,ISINPUT);
icolinfo[i].is_eof = 0;
}
Result = FNC_malloc(incount * SIZEOF_INTEGER);
OutHandle = (FNC_TblOpHandle_t*)FNC_TblOpOpen(0,'w',0);
isfirsttime = 1;
while(1)
{
allStreamsEOF = 1;
int ocount;
for(j=0; j < incount; j++)
{
if ( icolinfo[j].is_eof == 0)
Result[j] = FNC_TblOpRead(icolinfo[j].Handle);
if( Result[j] == TBLOP_EOF)
icolinfo[j].is_eof = 1;
else
if( Result[j] == TBLOP_SUCCESS)
icolinfo[j].is_eof = 0;
allStreamsEOF = allStreamsEOF & icolinfo[j].is_eof;
}
if(allStreamsEOF)
break;
/* We will write the o/p if atleast one non-dimesion o/p found a row */
foundrow = 0 ;
if( isfirsttime == 1 )
{
for( j=0; j < incount; j++)
{
if (icolinfo[j].dimension == 0 && icolinfo[j].is_eof == 0)
{
foundrow = 1;
}
}
}
if ( isfirsttime == 1 && foundrow == 0)
break;
isfirsttime = 0;
ocount = 0;
for(j=0; j < incount; j++)
{
Handle = icolinfo[j].Handle;
iCols = icolinfo[j].iCols;
for (i=0; i < iCols->num_columns; i++)
{
switch (iCols->column_types[i].datatype)
{
case CLOB_REFERENCE_DT:
case BLOB_REFERENCE_DT:
case JSON_DT:
case XML_DT:
case ST_GEOMETRY_DT:
/* This is output code, as we only have 1 outputstream should be 0 */
lrl_a[ocount] = FNC_LobCol2Loc(0, ocount);
if(icolinfo[j].is_eof == 0)
{
if (!(TBLOPISNULL(Handle->row->indicators,i)))
{
FNC_LobOpen_CL(Handle->row->columnptr[i], &lobid, 0, 0);
truncerr = 0;
while( FNC_LobRead(lobid, Buffer, BufferSize, &actlen) ==
0 && !truncerr)
truncerr=FNC_LobAppend (lrl_a[ocount], Buffer, actlen, &actlen);
FNC_LobClose(lobid);
}
}
break;
default:
if(icolinfo[j].is_eof == 0)
{
OutHandle->row->columnptr[ocount] = Handle->row->columnptr[i];
OutHandle->row->lengths[ocount] = Handle->row->lengths[i];
}
break;
}
if (icolinfo[j].is_eof == 1 || TBLOPISNULL(Handle->row->indicators,i))
{
TBLOPSETNULL(OutHandle->row->indicators,ocount);
}
ocount++;
}
}
FNC_TblOpWrite(OutHandle); // Writes current output row
}
for(i=0; i < incount; i++)
{
FNC_free(icolinfo[i].iCols);
FNC_TblOpClose(icolinfo[i].Handle); // close all contexts
}
FNC_free(icolinfo);
FNC_free(Result);
FNC_TblOpClose(OutHandle); // close all contexts
}