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基于openGauss内核开发的企业级关系型数据库。

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INSERT ALL&FIRST子句语法

功能描述

Insert All&First语句允许用户在一条Insert语句中往不同的表同时插入数据,也可以实现有条件的插入。

  • Insert All表示所有满足条件的插入语句都会被执行,并且INSERT ALL支持针对指定字段批量插入数据。

  • Insert First在执行第一个满足条件的插入语句后就会结束。

语法格式

Insert [ First | All ] 
[ WHEN { Condition } THEN INTO table [ [ AS ] alias ] [(column_name[,...])] Values (v1, ...), ...]
{ Subquery }

参数说明

  • WHEN { Condition }

    任意一个判断表达式。

    表达式中可以使用常量或引用查询中的表字段。

  • alias

    表的别名。

  • column_name[,…]

    指定字段的名称序列。

  • Subquery

    子查询语句。

注意事项

  • 指定字段功能即column_name选项仅在数据库兼容模式为Oracle时能够使用(即创建DB时DBCOMPATIBILITY='A'),在其他数据库兼容模式下不能使用该特性。

  • 指定字段功能暂不支持视图操作、自增列和with语法。

示例

示例1 使用insert all往不同的表批量指定字段插入数据。

1、创建数据库,设置兼容性为Oracle。

CREATE DATABASE my_test DBCOMPATIBILITY='A';
\c my_test
show sql_compatibility;

查看兼容性结果为:

 sql_compatibility
-------------------
 A
(1 row)

2、创建测试表1、表2。

create table test1
(id int,
sign_in date,
name varchar2(128),
last_id int,
last_name varchar2(128)
);

create table test2
(id int,
sign_in date,
name varchar2(128),
last_id int,
last_name varchar2(128)
);

3、指定字段批量插入数据。

INSERT ALL INTO test1 as TODO (id,sign_in,name,last_id,last_name)
VALUES (1,sysdate,'a',3,'c')
INTO test1 (id,sign_in,name)
VALUES (2,sysdate,'b')
INTO test2 (id,sign_in,name)
VALUES (1,sysdate,'a')
INTO test2 (id,sign_in,name,last_id,last_name)
VALUES (1,sysdate,'a',2,'b')
select 1 from dual;

4、查看插入数据结果。

select * from test1;
select * from test2;

显示结果为:

 id |    sign_in    | name | last_id | last_name
----+---------------+------+---------+-----------
  1 | 2022-10-14 14:23:31 | a    |       3 | c
  2 | 2022-10-14 14:23:31 | b    |         |
(2 rows)

 id |    sign_in    | name | last_id | last_name
----+---------------+------+---------+-----------
  1 | 2022-10-14 14:23:31 | a    |         |
  1 | 2022-10-14 14:23:31 | a    |       2 | b
(2 rows)

示例2 实现有条件的往不同的表批量插入数据。

1、创建测试表并插入数据。

CREATE TABLE small_orders 
  ( order_id       NUMERIC   NOT NULL,
    customer_id    NUMERIC    NOT NULL,
    order_total    NUMERIC );
CREATE TABLE medium_orders AS SELECT * FROM small_orders;
CREATE TABLE large_orders AS SELECT * FROM small_orders;
CREATE TABLE special_orders 
  (  order_id       NUMERIC  NOT NULL,
     customer_id    NUMERIC  NOT NULL,
     order_total    NUMERIC,
     other          NUMERIC
   );

CREATE TABLE orders 
(   order_id       NUMERIC NOT NULL,
    customer_id    NUMERIC NOT NULL,
    order_total    NUMERIC ,
    other          NUMERIC );

INSERT INTO orders SELECT 1, 1, 10000, 1 ;
INSERT INTO orders SELECT 1, 1, 20000, 1 ; 
INSERT INTO orders SELECT 1, 1, 30000, 1 ;
INSERT INTO orders SELECT 1, 1, 210000, 1 ;
INSERT INTO orders SELECT 1, 1, 220000, 1 ;
INSERT INTO orders SELECT 1, 1, 110000, 1 ;
INSERT INTO orders SELECT 1, 1, 120000, 1 ;
INSERT INTO orders SELECT 1, 1, 130000, 1 ;
INSERT INTO orders SELECT 1, 1, 140000, 1 ;
INSERT INTO orders SELECT 1, 1, 140000, 1 ;
INSERT INTO orders SELECT 1, 1, 340000, 1 ;

2、使用INSERT ALL向不同表中插入数据。

INSERT ALL
WHEN ottl < 100000 THEN
INTO small_orders
VALUES(oid, ottl, cid)
WHEN ottl > 100000 and ottl < 200000 THEN
INTO medium_orders
VALUES(oid, ottl, cid)
WHEN ottl > 200000 THEN
into large_orders
VALUES(oid, ottl, cid)
SELECT o.order_id oid, o.customer_id cid, o.order_total ottl,
o.other
FROM orders o;

3、查询INSERT ALL结果。

select * from small_orders;

返回结果如下,则表示插入数据成功:

 order_id | customer_id | order_total
----------+-------------+-------------
        1 |       10000 |           1
        1 |       20000 |           1
        1 |       30000 |           1
(3 rows)
select * from medium_orders;

返回结果如下,则表示插入数据成功:

 order_id | customer_id | order_total
----------+-------------+-------------
        1 |      110000 |           1
        1 |      120000 |           1
        1 |      130000 |           1
        1 |      140000 |           1
        1 |      140000 |           1
(5 rows)
select * from large_orders;

返回结果如下,则表示插入数据成功:

 order_id | customer_id | order_total
----------+-------------+-------------
        1 |      210000 |           1
        1 |      220000 |           1
        1 |      340000 |           1
(3 rows)
select * from special_orders;

返回结果如下,则表示插入数据成功:

 order_id | customer_id | order_total | other
----------+-------------+-------------+-------
(0 rows)

4、使用INSERT FIRST向不同表中插入数据。

INSERT First
WHEN ottl > 10000 THEN
INTO small_orders
VALUES(oid, ottl, cid)
INTO small_orders
VALUES(oid, ottl, cid)
INTO small_orders
VALUES(oid, ottl, cid)
WHEN ottl > 100000 THEN
INTO medium_orders
VALUES(oid, ottl, cid)
WHEN ottl > 200000 THEN
into large_orders
VALUES(oid, ottl, cid)
SELECT o.order_id oid, o.customer_id cid, o.order_total ottl,
o.other
FROM orders o;

5、查询INSERT First结果。

select * from small_orders;

返回结果如下,则表示插入数据成功:

 order_id | customer_id | order_total
----------+-------------+-------------
        1 |       10000 |           1
        1 |       20000 |           1
        1 |       30000 |           1
        1 |       20000 |           1
        1 |       20000 |           1
        1 |       20000 |           1
        1 |       30000 |           1
        1 |       30000 |           1
        1 |       30000 |           1
        1 |      210000 |           1
        1 |      210000 |           1
        1 |      210000 |           1
        1 |      220000 |           1
        1 |      220000 |           1
        1 |      220000 |           1
        1 |      110000 |           1
        1 |      110000 |           1
        1 |      110000 |           1
        1 |      120000 |           1
        1 |      120000 |           1
        1 |      120000 |           1
        1 |      130000 |           1
        1 |      130000 |           1
        1 |      130000 |           1
        1 |      140000 |           1
        1 |      140000 |           1
        1 |      140000 |           1
        1 |      140000 |           1
        1 |      140000 |           1
        1 |      140000 |           1
        1 |      340000 |           1
        1 |      340000 |           1
        1 |      340000 |           1
(33 rows)
select * from medium_orders;

返回结果如下(与第三步查询结果相同时),则表示语句执行成功:

 order_id | customer_id | order_total
----------+-------------+-------------
        1 |      110000 |           1
        1 |      120000 |           1
        1 |      130000 |           1
        1 |      140000 |           1
        1 |      140000 |           1
(5 rows)
select * from large_orders;

返回结果如下(与第三步查询结果相同时),则表示语句执行成功:

 order_id | customer_id | order_total
----------+-------------+-------------
        1 |      210000 |           1
        1 |      220000 |           1
        1 |      340000 |           1
(3 rows)
select * from special_orders;

返回结果如下(与第三步查询结果相同时),则表示语句执行成功:

 order_id | customer_id | order_total | other
----------+-------------+-------------+-------
(0 rows)