Example: Executing a Java Scalar UDF

Java scalar UDF code example.

1. Create the Java class.

   public class Sample {
   	public static int add( int a, int b ){
   		return a + b;
   	}
   }
   public class Sample {
   	public static int add( int a, int b ){
   		return new java.lang.Integer(a + b);
   	}
   }
   

2. Execute the SQL statement to deploy the Java class to the database.

   INSTALL JAVA NEW FROM FILE 'd:\\java\\samples\\Sample.class'

3. Create the SQL function that maps to the Java method “Sample.add( int, int)”.

   CREATE FUNCTION sample_add_int (IN a int, IN b int)
   RETURNS int
   EXTERNAL NAME 'Sample.add(II)I'
   LANGUAGE JAVA

4. Use the SQL function in a SELECT statement.

   SELECT sample_add_int( ID, ID ) from Customers WHERE ID < 110

5. Remove a Java class from the database.

   REMOVE JAVA CLASS ‘Sample’

6. Update a java class in the database.

   INSTALL JAVA UPDATE FROM FILE 'd:\\java\\samples\\Sample.class'
   INSTALL JAVA JAR UPDATE FROM FILE 'd:\\java\\samples\\Sample.jar'