Example: Executing a Java Table UDF with Java Result Set Construction

Java Table UDF code example. This example creates a result set.

1. Java code for Java creation of a return_rset method, for numeric values:

   public static void rowgenerator( int a, int b,  ResultSet rset[] ) {
   	int result = a + b;
   	// Create the meta data needed for the result set
   	ResultSetMetaDataImpl rsmd = new ResultSetMetaDataImpl(1);
   	rsmd.setColumnType(1, Types.INTEGER);
   	rsmd.setColumnName(1,"sum");
   	rsmd.setColumnLabel(1,"sum");
   	rsmd.setTableName(1,"my_sum");
   
   	// Create result set
   	ResultSetImpl rs = null;
   	try {
   		rs = new ResultSetImpl( (ResultSetMetaData)rsmd );
   		rs.beforeFirst();
   	} catch( Exception e ) {
   		System.out.println( "Error: couldn't create result set." );
   		System.out.println( e.toString() );
   	}
   
   	// Add the rows to the result set and populate them
   	try {
   		rs.insertRow();
   		rs.updateInt( 1, result );
   	} catch( Exception e ) {
   		System.out.println( "Error: couldn't insert row/data on row 1" );
   		System.out.println( e.toString() );
   	}
   	try {
   		rs.beforeFirst();
   	} catch( Exception e ) {
   		System.out.println( e.toString() );
   	}
   	rset[0] = rs;
   }

2. Java code for java creation of a return_rset method, for non-numerical values:

   public static void char_result_udf( java.lang.String s, ResultSet rset[]) {
   	// Create the meta data needed for the result set
   	ResultSetMetaDataImpl rsmd = new ResultSetMetaDataImpl(1);
   	rsmd.setColumnType(1, Types.CHAR);
   	if(s.length()==0){
   		rsmd.setColumnDisplaySize(1, 1);
   	} else { 
   		rsmd.setColumnDisplaySize(1,s.length() );
   	}
   	rsmd.setColumnName(1,"c1");
   	rsmd.setColumnLabel(1,"c1");
   	rsmd.setTableName(1,"my_string");
   
   	// Create result set
   	ResultSetImpl rs = null;
   	try {
   		rs = new ResultSetImpl( (ResultSetMetaData)rsmd );
   		rs.beforeFirst();
   		//Insert some values into the result set
   		rs.insertRow();
   		rs.updateString(1, c);
   	} catch( Exception e ) {
   		System.out.println( "Error: couldn't create result set." );
   		System.out.println( e.toString() );
   	try {
   		rs.beforeFirst();
   	} catch( Exception e ) {
   		System.out.println( "Error: couldn't insert row/data on row 1" );
   		System.out.println( e.toString() );
   	}
   	rset[0] = rs;