数据的增量更新之EXISTS

---drop table A
CREATE TABLE A
(
   id   int,
   name varchar(20),
   sex  nvarchar(2),
   age  int,
   hobby nvarchar(1000)
)
----drop table B
CREATE TABLE B
(
   id   int,
   name varchar(20),
   sex  nvarchar(2),
   age  int,
   hobby nvarchar(1000)
)


-----在A表插入数据
insert into A SELECT 1,‘连成壁‘,‘男‘,25,‘练剑‘

insert into A SELECT 2,‘逍遥侯‘,‘男‘,23,‘虐人‘

insert into A SELECT 3,‘杨开泰‘,‘男‘,25,‘泡妞‘


---------在B表插入数据
insert into B SELECT 1,‘连成壁‘,‘男‘,25,‘练剑‘

insert into B SELECT 2,‘逍遥侯‘,‘男‘,23,‘虐人‘


--------------数据的增量更新SQL(将表A中比表B中多的数据实现同步)
INSERT INTO B SELECT * FROM A WHERE NOT EXISTS(SELECT 1 FROM B WHERE A.id=B.id)