PrimaryキーまたはUniqueキーを指定して、レコードがなければINSERT、あればUPDATEしたい。
mysql
INSERT … ON DUPLICATE KEY UPDATE文を使う
mysql> desc foo;
+-------+--------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+--------------+------+-----+---------+-------+
| code | varchar(32) | NO | PRI | | |
| name | varchar(256) | YES | | NULL | |
+-------+--------------+------+-----+---------+-------+
mysql> insert into foo (code, name ) values ('0001', 'abc') on duplicate key update code='0001', name='def';
code='0001'のレコードがないので、insert
mysql> select * from foo;
+------+------+
| code | name |
+------+------+
| 0001 | abc |
+------+------+
mysql> insert into foo (code, name ) values ('0001', 'abc') on duplicate key update code='0001', name='def';
code='0001'のレコードがあるので、name='def'でupdate
+------+------+
| code | name |
+------+------+
| 0001 | def |
+------+------+
oracle
MERGE文を使う(9i以降）
Ex.
merge into user_master a
using (select '0056ddgd456' as user_id, 700 as user_point from dual ) b
on (a.user_id = b.user_id)
when matched then
update set
user_point = user_point + 100
when not matched then
insert (user_id, user_point)
values ('0056ddgd456', 100 );
dual表を使わない書き方もあるみたい。