Enhancements in Oracle 23c Introducing the NewOld Returning Clause

1. Enhancements in Oracle 23c: Introducing the New/Old
Returning Clause
Oracle 23c brings a host of new features aimed at simplifying application development. One
standout feature is the enhanced Returning Clause for Data Manipulation Language (DML)
operations, which now includes the ability to work with both NEW and OLD values. This addition
empowers developers to streamline their code, boost productivity, and enhance performance.
Understanding the Returning Clause:
The RETURNING INTO clause for INSERT, UPDATE, and DELETE statements has undergone
signi
fi
cant improvements. It now provides a comprehensive report on the OLD and NEW values
a
ff
ected by the respective statement.
This means that developers can employ the same logic for all DML types to retrieve values before
and after the execution of a statement.
It’s important to note that old and new values are only applicable to UPDATE statements.
INSERT statements exclusively return new values, while DELETE statements only report old
values.
The Evolution from the Previous Norm:
Previously, Oracle’s returning clause primarily focused on providing new values. For example, in
cases where an application inserted data into a table, it would return an auto-generated ID for the
row. In the context of updates, developers could return the ID along with the updated row and
other relevant columns. While it was possible to retrieve old column values for updates through
some workarounds, it was by no means straightforward. Oracle’s commitment to simplifying the
process for application developers led to the introduction of this feature as a SQL clause.
Utilizing the New Returning Clause:
This newly enhanced feature allows developers to retrieve either a single row/value or multiple
rows/values, o
ff
ering a
fl
exible and dynamic approach to data manipulation. Let’s delve into a
example:
set serveroutput on
DROP table if exists TEST_TAB purge;
CREATE TABLE TEST_TAB (columnA VARCHAR2(10), columnB number);
INSERT INTO TEST_TAB(columnA, columnB) VALUES ('Test', 10);
INSERT INTO TEST_TAB(columnA, columnB) VALUES ('Row 2', 20);
CREATE TABLE IF not exists audit_table1(col_new VARCHAR2(10),col_old VARCHAR2(10),
columnB number);
DECLARE
TYPE columnA_TYPE IS TABLE OF TEST_TAB.columnA%TYPE;
OLD_columnA columnA_TYPE;
NEW_columnA columnA_TYPE;
BEGIN
UPDATE TEST_TAB AA
SET AA.columnA = 'NEW_VALUE'
WHERE AA.columnB < 30

2. RETURNING OLD columnA, NEW columnA
BULK COLLECT INTO OLD_columnA, NEW_columnA;
FOR I IN 1 .. OLD_columnA.COUNT LOOP
DBMS_OUTPUT.PUT_LINE('Old.columnA = ' || OLD_columnA(I));
DBMS_OUTPUT.PUT_LINE('New.columnA = ' || NEW_columnA(I));
--insert into audit_table1 values ( NEW_columnA, OLD_columnA);
END LOOP;
END;
Output
-------------------
Old.columnA = Test
New.columnA = NEW_VALUE
Old.columnA = Row 2
New.columnA = NEW_VALUE
Oracle 23c’s enhanced RETURNING clause can come in handy in application auditing,
Application level Change Data Capture, and many application-driven logic.
This powerful feature promises to be a game-changer for developers seeking code e
ffi
ciency,
precision, and performance in their applications.
Insert and Delete
The NEW and OLD keywords can be used on INSERT and DELETE also, but they don't bring
anything new to the table. For inserts we have no old values, and for deletes we have no new
values.
set serveroutput on
declare
l_old_code t1.code%type;
l_old_description t1.description%type;
l_new_code t1.code%type;
l_new_description t1.description%type;
begin
insert into t1 (id, code, description)
values (5, 'FIVE', 'Description for FIVE')
returning old code , old description, new code, new description
into l_old_code, l_old_description, l_new_code, l_new_description;
dbms_output.put_line('l_old_code = ' || l_old_code);
dbms_output.put_line('l_old_description = ' || l_old_description);
dbms_output.put_line('l_new_code = ' || l_new_code);
dbms_output.put_line('l_new_description = ' || l_new_description);
rollback;
END;
/
------------------
l_old_code =
l_old_description =
l_new_code = FIVE
l_new_description = Description for FIVE
PL/SQL procedure successfully completed.

3. SQL>
--------------------------
set serveroutput on
declare
l_old_code t1.code%type;
l_old_description t1.description%type;
l_new_code t1.code%type;
l_new_description t1.description%type;
begin
delete from t1
where id = 2
returning old code , old description, new code, new description
into l_old_code, l_old_description, l_new_code, l_new_description;
dbms_output.put_line('l_old_code = ' || l_old_code);
dbms_output.put_line('l_old_description = ' || l_old_description);
dbms_output.put_line('l_new_code = ' || l_new_code);
dbms_output.put_line('l_new_description = ' || l_new_description);
rollback;
END;
/
l_old_code = TWO
l_old_description = Description for TWO
l_new_code =
l_new_description =
PL/SQL procedure successfully completed.
SQL>
Also you can use this feature instead of Golden gate to achieve xhange data capture (CDC) using
some manually scripts.
Alireza Kamrani.