Oracle — insert into,insert all into,insert first into的区别

1、建测试表

CREATE TABLE EDW_INT   
(   
  AGMT_NO         VARCHAR2(40 BYTE)             NOT NULL,   
  AGMT_SUB_NO     VARCHAR2(4 BYTE)              NOT NULL,   
  NEED_REPAY_INT  NUMBER(22,2),   
  CURR_PERIOD     NUMBER(4)                     NOT NULL   
);   
CREATE TABLE EDW_INT_1   
(   
  AGMT_NO         VARCHAR2(40 BYTE)             NOT NULL,   
  AGMT_SUB_NO     VARCHAR2(4 BYTE)              NOT NULL,   
  NEED_REPAY_INT  NUMBER(22,2),   
  CURR_PERIOD     NUMBER(4)                     NOT NULL   
);   
CREATE TABLE EDW_INT_2   
(   
  AGMT_NO         VARCHAR2(40 BYTE)             NOT NULL,   
  AGMT_SUB_NO     VARCHAR2(4 BYTE)              NOT NULL,   
  NEED_REPAY_INT  NUMBER(22,2),   
  CURR_PERIOD     NUMBER(4)                     NOT NULL   
);  

2、插入测试数据

INSERT INTO EDW_INT   
  (AGMT_NO, AGMT_SUB_NO, NEED_REPAY_INT, CURR_PERIOD)   
VALUES   
  ('20003874', '2104', 3126.5, 7);   
INSERT INTO EDW_INT   
  (AGMT_NO, AGMT_SUB_NO, NEED_REPAY_INT, CURR_PERIOD)   
VALUES   
  ('20003874', '2104', 3290.76, 6);   
INSERT INTO EDW_INT   
  (AGMT_NO, AGMT_SUB_NO, NEED_REPAY_INT, CURR_PERIOD)   
VALUES   
  ('20003874', '2104', 3454.06, 5);   
INSERT INTO EDW_INT   
  (AGMT_NO, AGMT_SUB_NO, NEED_REPAY_INT, CURR_PERIOD)   
VALUES   
  ('20003874', '2104', 3616.41, 4);   
INSERT INTO EDW_INT   
  (AGMT_NO, AGMT_SUB_NO, NEED_REPAY_INT, CURR_PERIOD)   
VALUES   
  ('20017143', '2104', 2350.86, 0);   
INSERT INTO EDW_INT   
  (AGMT_NO, AGMT_SUB_NO, NEED_REPAY_INT, CURR_PERIOD)   
VALUES   
  ('20017143', '2104', 3566.55, 0);   
INSERT INTO EDW_INT   
  (AGMT_NO, AGMT_SUB_NO, NEED_REPAY_INT, CURR_PERIOD)   
VALUES   
  ('20018273', '2104', 1639.46, 0);   
INSERT INTO EDW_INT   
  (AGMT_NO, AGMT_SUB_NO, NEED_REPAY_INT, CURR_PERIOD)   
VALUES   
  ('20018273', '2104', 2080.49, 0);   
COMMIT;  

3、insert all/first语句示例

(1)、insert all-不带条件

insert all   
into edw_int_1(agmt_no,agmt_sub_no,need_repay_int,curr_period)   
values(agmt_no,agmt_sub_no,need_repay_int,curr_period)   
into edw_int_2(agmt_no,agmt_sub_no,curr_period)   
values(agmt_no,'1234',curr_period)   
select agmt_no,agmt_sub_no,need_repay_int,curr_period from edw_int;   
commit;  

(2)、insert all-带条件

insert all   
when curr_period=0 then    
into edw_int_1(agmt_no,agmt_sub_no,need_repay_int,curr_period)   
values(agmt_no,agmt_sub_no,need_repay_int,curr_period)   
else  
into edw_int_2(agmt_no,agmt_sub_no,need_repay_int,curr_period)   
values(agmt_no,agmt_sub_no,need_repay_int,curr_period)   
select agmt_no,agmt_sub_no,need_repay_int,curr_period from edw_int;   
commit; 

(3)、insert first-带条件

insert first   
when curr_period=0 then    
into edw_int_1(agmt_no,agmt_sub_no,need_repay_int,curr_period)   
values(agmt_no,agmt_sub_no,need_repay_int,curr_period)   
when agmt_sub_no='2104' then   
into edw_int_2(agmt_no,agmt_sub_no,need_repay_int,curr_period)   
values(agmt_no,agmt_sub_no,need_repay_int,curr_period)   
select agmt_no,agmt_sub_no,need_repay_int,curr_period from edw_int;   
commit;  

4、数据结果查看

truncate table edw_int_1;   
truncate table edw_int_2;   
select * from edw_int;   
select * from edw_int_1;   
select * from edw_int_2;  

5、all与first的区别

all:不考虑先后关系，只要满足条件，就全部插入；

first:考虑先后关系，如果有数据满足第一个when条件又满足第二个when条件，则执行第一个then插入语句，第二个then就不插入第一个then已经插入过的数据了。

其区别也可描述为，all只要满足条件，可能会作重复插入；first首先要满足条件，然后筛选，不做重复插入。