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I’m testing GridDB Cloud with the C client. I insert a couple of rows into a container, but when I query them back, the row values sometimes come out as NULL (empty), even though I just inserted data.

Here’s a minimal example:

GSContainer *cont;
GSRow *row;
GSQuery *qry;
GSRowSet *rs;

// create row and insert
gsGetContainer(store, "sensor_data", &cont);

gsCreateRowByContainer(cont, &row);
gsSetRowFieldByString(row, 0, "sensor-01");
gsSetRowFieldByFloat(row, 1, 22.5f);
gsSetRowFieldByTimestamp(row, 2, gsCurrentTime());
gsPutRow(cont, NULL, row, NULL);
gsCloseRow(&row);

// query back
qry = gsQuery(cont, "SELECT *");
gsFetch(qry, &rs);

while (gsHasNextRow(rs)) {
    GSRow *fetched;
    gsNextRow(rs, &fetched);

    const char *id;
    float temp;
    GSTimestamp ts;

    gsGetRowFieldAsString(fetched, 0, &id);
    gsGetRowFieldAsFloat(fetched, 1, &temp);
    gsGetRowFieldAsTimestamp(fetched, 2, &ts);

    printf("id=%s temp=%.2f ts=%lld\n", id, temp, (long long)ts);
    gsCloseRow(&fetched);
}

I expected to get back the same row values:

  • sensor-01

  • 22.5

  • timestamp

Sometimes id prints (null) and temp prints 0.00.

Am I handling gsNextRow and gsGetRowFieldAs… correctly? Do I need to commit/flush after gsPutRow, or is there something else in the C API that ensures the data is visible immediately after insert?

Improve this question
3
  • Have you tried to remove gsCloseRow(&fetched); and also move GSRow *fetched; before the loop? Commented Sep 11 at 10:02
  • 1
    Hassan Saeed, gsGetRowFieldAsString() and others return a value. Re-write code to check each function return value and the answer will certainly become more clear. Its faster than posting on SO. Commented Sep 11 at 10:15
  • Thanks, I’ll try moving GSRow *fetched before the loop and avoid closing it too early. Commented Sep 11 at 11:08
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