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Horst 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:
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2 Comments

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    1. Horst Keller

       

      Well yes, of course. Native SQL is native SQL and therefore platform dependent. That’s the main difference to Open SQL and that’s why we recommend Open SQL.

      The ABAP documentation clearly states that and doesn’t claim that its Native SQL examples work on each platform. In recent versions of the documentation, the examples are written and tested for HANA only.

      (0) 

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