ORACLE RETURNING 语句的使用方法

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　　1.The
RETURNING INTO clause allows us to return column values for rows
affected by DML statements. The following test table is used to
demonstrate this clause.


　　


　　


　　

DROP TABLE t1;
DROP SEQUENCE t1_seq;
CREATE TABLE t1 (
ID NUMBER(10),
DESCRIPTION VARCHAR2(50),
CONSTRAINT t1_pk PRIMARY KEY (id));
CREATE SEQUENCE t1_seq;
INSERT INTO t1 VALUES (t1_seq.nextval, 'ONE');
INSERT INTO t1 VALUES (t1_seq.nextval, 'TWO');
INSERT INTO t1 VALUES (t1_seq.nextval, 'THREE');
COMMIT;
 　　
　　2.When we insert data using a sequence to generate our primary key value, we can return the primary key value as follows.


　　


　　

SET SERVEROUTPUT ON
DECLARE
v_id t1.id%TYPE;
BEGIN
INSERT INTO t1
VALUES (t1_seq.nextval, 'FOUR')
RETURNING id INTO v_id;
COMMIT;
DBMS_OUTPUT.put_line('ID=' || v_id);
END;
/
　　
　　ID
=
4



　　
　　


　　3.The syntax is also available for update and delete statements.


　　


　　

SET SERVEROUTPUT ON
DECLARE
v_id t1.id%TYPE;
BEGIN
UPDATE t1
SET description = description
WHERE description = 'FOUR'
RETURNING id INTO v_id;
DBMS_OUTPUT.put_line('UPDATE ID=' || v_id);
DELETE FROM t1
WHERE description = 'FOUR'
RETURNING id INTO v_id;
DBMS_OUTPUT.put_line('DELETE ID=' || v_id);
COMMIT;
END;
/
　　
　　UPDATE


ID
=
4



　　DELETE


ID
=
4



　　
　　


　　4.When
DML affects multiple rows we can still use the RETURNING INTO, but now
we must return the values into a collection using the BULK COLLECT
clause.


　　



SET SERVEROUTPUT ON
DECLARE
TYPE t_tab IS TABLE OF t1.id%TYPE;
v_tab t_tab;
BEGIN
UPDATE t1
SET description = description
RETURNING id BULK COLLECT INTO v_tab;
FOR i IN v_tab.first .. l_tab.last LOOP
DBMS_OUTPUT.put_line('UPDATE ID=' || l_tab(i));
END LOOP;
COMMIT;
END;
/
　　UPDATE


ID
=
1



　　UPDATE


ID
=
2



　　UPDATE


ID
=
3



　　
　　


　　5.We can also use the RETURNING INTO clause in combination with bulk binds.



SET SERVEROUTPUT ON
DECLARE
TYPE t_desc_tab IS TABLE OF t1.description%TYPE;
TYPE t_tab IS TABLE OF t1%ROWTYPE;
l_desc_tab t_desc_tab := t_desc_tab('FIVE', 'SIX', 'SEVEN');
l_tab t_tab;
BEGIN
FORALL i IN l_desc_tab.first .. l_desc_tab.last
INSERT INTO t1
VALUES (t1_seq.nextval, l_desc_tab(i))
RETURNING id, description BULK COLLECT INTO l_tab;
FOR i IN l_tab.first .. l_tab.last LOOP
DBMS_OUTPUT.put_line('INSERT ID=' || l_tab(i).id || ' DESC=' || l_tab(i).description);
END LOOP;
COMMIT;
END;
 /

　　INSERT


ID
=
5


DESC
=FIVE



　　INSERT


ID
=
6


DESC
=SIX



　　INSERT


ID
=
7


DESC
=SEVEN



　　
　　


　　6.This functionality is also available from dymanic SQL.


　　



SET SERVEROUTPUT ON
DECLARE
TYPE t_tab IS TABLE OF t1.id%TYPE;
l_tab t_tab;
BEGIN
EXECUTE IMMEDIATE 'UPDATE t1
SET description = description
RETURNING id INTO :l_tab'
RETURNING BULK COLLECT INTO l_tab;
FOR i IN l_tab.first .. l_tab.last LOOP
DBMS_OUTPUT.put_line('UPDATE ID=' || l_tab(i));
END LOOP;
COMMIT;
END;
/
　　UPDATE


ID
=
1



　　UPDATE


ID
=
2



　　UPDATE


ID
=
3