Java-Sprache simulierte Zeilenfunktion

import org.netezza.ae.*;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
public class TestJavaTime {
private static final Executor exec =
Executors.newCachedThreadPool();
public static final void main(String [] args) {
try {
mainImpl(args);
} catch (Throwable t) {
System.err.println(t.toString());
NzaeUtil.logException(t, "main");
}
}
public static final void mainImpl(String [] args) {
NzaeApiGenerator helper = new NzaeApiGenerator();
while (true) {
final NzaeApi api = helper.getApi(NzaeApi.FUNCTION);
if (api.apiType == NzaeApi.FUNCTION) {
if (!helper.isRemote()) {
run(api.aeFunction);
break;
} else {
Runnable task = new Runnable() {
public void run() {
try {
TestJavaTime.run(api.aeFunction);
} finally {
api.aeFunction.close();
}
}
};
exec.execute(task);
}
}
}
helper.close();
}
public static class MyHandler implements NzaeMessageHandler
{
public void evaluate(Nzae ae, NzaeRecord input, NzaeRecord output) {
final NzaeMetadata meta = ae.getMetadata();
int op = 0;
double result = 0;
if (meta.getOutputColumnCount() != 3 ||
meta.getOutputNzType(0) != NzaeDataTypes.NZUDSUDX_INT32 ||
meta.getOutputNzType(1) != NzaeDataTypes.NZUDSUDX_INT32 ||
meta.getOutputNzType(2) != NzaeDataTypes.NZUDSUDX_INT32
) {
throw new NzaeException("expecting three output columns of "+
"type int32");
}
if (meta.getInputColumnCount() != 1) {
throw new NzaeException("expecting one input column");
}
if (meta.getInputNzType(0) != NzaeDataTypes.NZUDSUDX_FIXED &&
meta.getInputNzType(0) != NzaeDataTypes.NZUDSUDX_VARIABLE) {
throw new NzaeException("first input column expected to be a "+
"string type");
}
int hour, min, sec;
Object field = input.getField(0);
if (field == null)
throw new NzaeException("first input column may not be null");
String sf = (String)field;
String[] ar = sf.split(":");
if (ar.length != 3)
throw new NzaeException("Badly formatted time " + sf + ". "+
"Expected h:m:s");
hour = Integer.parseInt(ar[0]);
min = Integer.parseInt(ar[1]);
sec = Integer.parseInt(ar[2]);
output.setField(0, hour);
output.setField(1,min);
output.setField(2, sec);
}
}
public static int run(Nzae ae)
{
ae.run(new MyHandler());
return 0;
}
}

Kompilieren Sie den Code:

$NZ_EXPORT_DIR/ae/utilities/bin/compile_ae --language java \
--template compile TestJavaTime.java --version 3

Da es in Netezza SQL kein eingebautes Konzept für eine Zeilenfunktion gibt, wird diese Funktion als Tabellenfunktion registriert, obwohl sie nur eine Zeile pro Eingabezeile ausgibt:

$NZ_EXPORT_DIR/ae/utilities/bin/register_ae --sig "timeae(VARCHAR(ANY))" \
--return "table(hour int4, minute int4, second int4)" --class AeUdtf \
--language java --template udtf --version 3 --define \
"java_class=TestJavaTime"

Führen Sie die Abfrage in nzsql aus:

SELECT * FROM TABLE WITH FINAL(timeae('12:30:15'));
HOUR | MINUTE | SECOND
------+--------+--------
12 | 30 | 15
(1 row)
SELECT * FROM TABLE WITH FINAL(timeae('12:30'));
ERROR: Badly formatted time 12:30. Expected h:m:s