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
