JDBC SELECT COUNT(*) returns empty resultset on HSQLDB - select

Question

I would expect to always receive a resultset with one row on a SELECT COUNT, but results.next() always returns false. This is on HSQLDB 2.5.1.
The code below prints:
number of columns: 1. First column C1 with type INTEGER
No COUNT results
statement = connection.createStatement();
// check if table empty
statement.executeQuery("SELECT COUNT(*) FROM mytable");
ResultSet results = statement.getResultSet();
System.out.println("number of columns: " + results.getMetaData().getColumnCount() + ". First column " +results.getMetaData().getColumnName(1) + " with type " +results.getMetaData().getColumnTypeName(1) );
int numberOfRows = 0;
boolean hasResults = results.next();
if (hasResults){
numberOfRows = results.getInt(1);
System.out.println("Table size " + numberOfRows );
}else{
System.out.println("No COUNT results" );
}
statement.close();
Executing the same SQL statement in my SQL console works fine:
C1
104
Other JDBC actions on this database work fine as well.
Is there something obvious I'm missing?

Answer 1

The getResultSet method is applicable to execute, but not executeQuery which returns a ResultSet. That is the one you need to refer to, at the moment you are losing it as you are not assigning it to anything.
See https://docs.oracle.com/javase/7/docs/api/java/sql/Statement.html#executeQuery(java.lang.String) and https://docs.oracle.com/javase/7/docs/api/java/sql/Statement.html#getResultSet()
ResultSet results = statement.executeQuery("SELECT COUNT(*) FROM mytable");