Chapter 12 Calling EAServer Component Methods from PowerDynamo

Working with tabular results

When a Dynamo script calls an EAServer component through Java, results are returned as Tabular ResultSets. Tabular ResultSets have different properties and methods than the Dynamo query object. Dynamo includes a script called javaqry.ssc that is installed in the system/utils folder of the Dynamo web site. This script implements a class called JavaQuery which takes as a parameter a TabularResults Set object sent by EAServer and returns a class that has methods mimicking those of a Dynamo query object.

Scripts that call an EAServer component through Java and do not make use of the JavaQuery class look something like this:

comp = java.CreateComponent( "SVU/SVUEnrollment" );
prequery = comp.getMajors();
query = java.CallStaticMethod( "com.sybase.CORBA.jdbc11.SQL","getResultSet",prequery );
received = query.next();
metadata = query.getMetaData();
columns = metadata.getColumnCount();
document.writeln( "There are " + columns + " columns" );
while( received ) {
    fields = query.Fields;
    for( j = 0; j < columns; j++ ) {
        value = query.getString( j )
        document.writeln( value );
    }
    received = query.next();
}

Using the JavaQuery class, you could use:

import ~/system/utils/javaqry.ssc;

comp = java.CreateComponent( "SVU/SVUEnrollment" );
// returns Tabular ResultSet object
query = comp.getMajors();
// wrap up the Tabular ResultSet to mimic a Dynamo query 
//object
dynQuery = new JavaQuery( query );
columns = dynQuery.GetColumnCount();
document.writeln( "There are " + columns + " columns" );
while( dynQuery.MoveNext() ) {
    for( j = 0; j <= columns; j++ ) {
        value = dynQuery.GetValue(j);
        document.writeln( value );
    }
}