Returns the size of the result (number of rows returned), or -1 if the size cannot be determined or if the database does not support reporting information about query sizes.
qid (scalar) – query number.
result_size (scalar) – number of rows in the current result set of the active query. If the number of rows cannot be determined a -1 is returned.
// Given a table with US States. qid = dbCreateQuery(db_id, "SELECT * FROM STATES"); count = dbQueryRows(qid); // count = 50
Note that if the query is not active or if the query is not a
statement, a -1 is returned. These properties can be checked with