Fetching Blob Data from Selected Rows
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Go Up to Reading Data from a Blob
A looping construct is used to fetch (into the output XSQLDA) the column data for a single row at a time from the select-list and to process each row before the next row is fetched. Each execution of isc_dsql_fetch() fetches the column data into the corresponding XSQLVAR substructures of out_sqlda. For the Blob column, the Blob ID, not the actual Blob data, is fetched.
ISC_STATUS fetch_stat;
long SQLCODE;
. . .
while ((fetch_stat = isc_dsql_fetch(status_vector, &stmt, 1, out_sqlda))
== 0)
{
proj_name[PROJLEN] = '\0';
prod_type[TYPELEN] = '\0';
printf("\nPROJECT: %–20s TYPE: %–15s\n\n", proj_name, prod_type);
/* Read and process the Blob data (see next section) */
}
if (fetch_stat != 100L) {
/* isc_dsql_fetch returns 100 if no more rows remain to be
retrieved */
SQLCODE = isc_sqlcode(status_vector);
isc_print_sqlerror(SQLCODE, status_vector);
return(1);
}