RETURNING INTO的简单用法

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');

returning into语句的主要作用是：

delete操作：returning返回的是delete之前的结果

insert操作:returning返回的是insert之后的结果

update操作:returning语句是返回update之后的结果

注意：returning into语句不支持insert into select 语句和merge语句

下面演示该语句的具体用法

（1）获取添加的值

declare
l_id t1.id%type;
begin
insert into t1 values(t1_seq.nextval,'four')
returning id into l_id;
commit;
dbms_output.put_line('id='||l_id);
end

运行结果 id=4

(2)更新和删除

1 DECLARE l_id t1.id%TYPE;
2 BEGIN
3 UPDATE t1
4 SET description = 'two2'
5 WHERE ID=2
6 RETURNING id INTO l_id;
7 DBMS_OUTPUT.put_line('UPDATE ID=' || l_id);
8 DELETE FROM t1 WHERE description = 'THREE'
9 RETURNING id INTO l_id;
10 DBMS_OUTPUT.put_line('DELETE ID=' || l_id);
11 COMMIT;
12* END;
SQL> /
UPDATE ID=2
DELETE ID=3
（3）如果更新dml操作影响多条记录可以通过bulk collect into 来提取
1 declare
2 type t_tab is table of t1.id%type;
3 l_tab t_tab;
4 begin
5 update t1
6 set description=description
7 returning id bulk collect into l_tab;
8 for i in l_tab.first..l_tab.last loop
9 dbms_output.put_line('update id='||l_tab(i));
10 end loop;
11* end;
SQL> /
update id=21
update id=22
update id=23
（4）如果插入操作影响多行也可以获取

declare
type description_table_type is table of t1.description%type;
type t1_table_type is table of t1%rowtype;
description_table description_table_type:=description_table_type('FIVE', 'SIX', 'SEVEN');
t1_table t1_table_type;
begin
forall i in description_table.first..description_table.last
insert into t1 values(t1_seq.nextval,description_table(i))
returning id ,description bulk collect into t1_table;
for i in t1_table.first..t1_table.last loop
DBMS_OUTPUT.put_line('INSERT ID=' || t1_table(i).id ||'DESC='|| t1_table(i).description);
end loop;
end;
/

执行结果

INSERT ID=27DESC=FIVE
INSERT ID=28DESC=SIX
INSERT ID=29DESC=SEVEN

PL/SQL procedure successfully completed.

forall指的是同时插入，如果使用for循环也可以插入三条记录，但默认returing只显示最后一条