ADBC and JDBC

[JerryWang]

horst.keller has already introduced ADBC in his blog ABAP Geek 15 – ADBC long times ago. And recently during my self study on PostgreSQL I made some practice to connect PostgreSQL in Java programming using Java Database Connectivity - JDBC. In fact I found out that there are lots of commonality between these two technologies.

There is a demo program demo_adbc_query mentioned in SAP help to demonstrate the use of ADBC.

I make some changes on it in order to perform a line-by-line comparison with JDBC.

The source code of adapted program:

REPORT zjerry_adbc.



CLASS demo DEFINITION.

  PUBLIC SECTION.

    CLASS-METHODS main.

  PRIVATE SECTION.

    CLASS-DATA: BEGIN OF result_line,

                  carrid TYPE sflight-carrid,

                  connid TYPE sflight-connid,

                  fldate TYPE sflight-fldate,

                END OF result_line,

                result_tab LIKE TABLE OF result_line.

ENDCLASS.



CLASS demo IMPLEMENTATION.

  METHOD main.

    DATA: carrid    TYPE sflight-carrid VALUE 'AA',

          cols      TYPE adbc_column_tab,

          lv_carrid TYPE string,

          con_ref   TYPE REF TO cl_sql_connection,

          con_name  TYPE dbcon-con_name VALUE 'DEFAULT'.



    cols = VALUE #( ( CONV adbc_name( 'CARRID' ) )

                    ( CONV adbc_name( 'CONNID' ) )

                    ( CONV adbc_name( 'FLDATE' ) ) ).

    lv_carrid = cl_abap_dyn_prg=>quote( to_upper( carrid ) ).

    TRY.

        con_ref = cl_sql_connection=>get_connection( con_name ).

        DATA(statement) = con_ref->create_statement( ).

        DATA(lv_query) = `SELECT carrid, connid, fldate ` &&

         `FROM sflight ` &&

         `WHERE mandt  = ` && `'` && sy-mandt && `' AND` &&

         `      carrid = ` &&  lv_carrid.

        DATA(result) = statement->execute_query( lv_query ).

        result->set_param_table( itab_ref = REF #( result_tab )

                                 corresponding_fields = cols ).

        IF result->next_package( ) > 0.

          SORT result_tab BY carrid connid fldate.

          WRITE:/ 'Number of lines found: ', lines( result_tab ).

        ENDIF.

        con_ref->close( ).

      CATCH cx_sql_exception INTO DATA(err).

    ENDTRY.

  ENDMETHOD.

ENDCLASS.



START-OF-SELECTION.

  demo=>main( ).

And now have a look at how JDBC can achieve the same.

I have replicated an ABAP table COMM_PRODUCT to my local PostgreSQL server:

And I manually inserted two test records into it:

Both is the source code implemented in Java to perform a query against this table and display result：

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import java.sql.Timestamp;

public class PostgreSQLJDBC {

	private Connection connection = null;

	private void select() {

		try {

			int index = 0;

			Class.forName("org.postgresql.Driver");

			connection = DriverManager.getConnection(

					"jdbc:postgresql://localhost:9812/zproduct", "postgres", "XXXXXX");

			Statement stmt = connection.createStatement();

			String query = "SELECT * FROM public.comm_product;";

			ResultSet rs = stmt.executeQuery(query);

	         while ( rs.next() ) {

	        	System.out.println("Row index: " + index++);

	        	String  client = rs.getString("client");

	            System.out.println("Client: " + client);

	            String  guid = rs.getString("product_guid");

	            System.out.println("Product guid: " + guid);

	            Timestamp validFrom = rs.getTimestamp("valid_from");

	            System.out.println("Valid from: " + validFrom);

	         }

	         rs.close();

	         stmt.close();

	         connection.close();

		} catch (Exception e) {

			e.printStackTrace();

		} 

	}

	public static void main(String args[]) {

		PostgreSQLJDBC jdbcTest = new PostgreSQLJDBC();

		jdbcTest.select();

	}

}

Output in console:

And I mark the corresponding part in both language which has the same semantic meaning with same color ( although grammar is different ).

Through this comparison we can know that both connectivity technology follow the same idea.

Further reading

I have written a series of blogs which compare the language feature among ABAP, JavaScript and Java. You can find a list of them below:

• Lazy Loading, Singleton and Bridge design pattern in JavaScript and in ABAP


• 
  
  Functional programming – Simulate Curry in ABAP


• 
  
  Functional Programming – Try Reduce in JavaScript and in ABAP


• 
  
  Simulate Mockito in ABAP


• 
  
  A simulation of Java Spring dependency injection annotation @Inject in ABAP


• 
  
  Singleton bypass – ABAP and Java


• 
  
  Weak reference in ABAP and Java


• Fibonacci Sequence in ES5, ES6 and ABAP


• Java byte code and ABAP Load


• How to write a correct program rejected by compiler: Exception handling in Java and in ABAP


• An small example to learn Garbage collection in Java and in ABAP


• String Template in ABAP, ES6, Angular and React


• Try to access static private attribute via ABAP RTTI and Java Reflection


• Local class in ABAP, Java and JavaScript


• Integer in ABAP, Java and JavaScript


• Covariance in Java and simulation in ABAP


• Various Proxy Design Pattern implementation variants in Java and ABAP


• Tag(Marker) Interface in ABAP and Java


• Bitwise operation ( OR, AND, XOR ) on ABAP Integer


• ABAP ICF handler and Java Servlet


• ADBC and JDBC


• CL_ABAP_CORRESPONDING, CL_JAVA_CORRESPONDING and CL_JS_CORRESPONDING


• Build an Cross Site Scripting example in Java and ABAP


• Play around with JSONP in nodeJS server and ABAP server