Question

I get the error “JDBCExceptionReporter – incompatible data types in combination” when running the following code:

    public Collection<SensorReading> getLastReadings(int[] sensorIds)
    throws DataAccessException {
            StringBuilder sb = new StringBuilder();
    sb.append("SELECT r ");
    sb.append("FROM Sensor AS s, SensorReading AS r ");
    sb.append("WHERE s.id IN (");
    for(int sensId:sensorIds){
        sb.append("'");
        sb.append(sensId);
        sb.append("',");
    }
    //strip off the last comma
    sb.setLength(sb.length() -1);
    //build the rest of the query
    sb.append(")  AND s.id = r.sensorId ");
    sb.append("   AND r.readingTimestampUtc >= s.lastBeaconUtc ");
    List<SensorReading> readings = getHibernateTemplate().find(sb.toString());
    //map to hold only the latest result
    Map<Integer, SensorReading> readingsMap = new HashMap<Integer, SensorReading>();
    //flash through the readings and make sure there's only one per sensor ID
    for(SensorReading rdg:readings){
        Integer sensorId = rdg.getSensorId();
        SensorReading reading = readingsMap.get(sensorId);
        if(reading==null){
            readingsMap.put(sensorId, rdg);
        }
        else{
            //replace if the new reading is later
            if(reading.getReadingTimestampUtc().after(rdg.getReadingTimestampUtc())){
                readingsMap.put(sensorId, reading);
            }
        }
    }
    return readingsMap.values();
}

sensor id and sensorreading sensorid are all integers and the other joins are dates. Any ideas why i might be getting this?

Answer 1

Yikes! The problem was the quotes around the IDs in the list.

Why doesn’t hibernate deal with this properly?