create table table1
(number int, age int)
insert table1
select 100, 20
union all
select 101, 45
union all
select 103, 60create table table2
(number int, age int)
insert table2
select 100, 22
union all
select 102, 30
union all
select 103, 35update table1
set age=table2.age
from table2
where table1.number=table2.numberselect * into table3 from table1select * from table3number age
----------- -----------
100 22
101 45
103 35(所影响的行数为 3 行)
(number int, age int)
insert table1
select 100, 20
union all
select 101, 45
union all
select 103, 60create table table2
(number int, age int)
insert table2
select 100, 22
union all
select 102, 30
union all
select 103, 35update table1
set age=table2.age
from table2
where table1.number=table2.numberselect * into table3 from table1select * from table3number age
----------- -----------
100 22
101 45
103 35(所影响的行数为 3 行)
insert into @table1
select 100,20 union
select 101,45 union
select 103,60declare @table2 table(number int,age int)
insert into @table2
select 100,22 union
select 102,30 union
select 103,35--取age为成年(18~59)的记录
select number,max(age)age from (
select * from @table1
union
select * from @table2
)a
where age between 18 and 59 and exists(select number from @table1 where number=a.number)
group by number-------结果-----
number age
----------- -----------
100 22
101 45
103 35(所影响的行数为 3 行)
FROM A, B
WHERE A.NUMBER = B.NUMBER
SELECT A.NUMBER,
CASE WHEN A.AGE > B.AGE THEN A.AGE ELSE B.AGE END AGE
FROM TABLE1 A, TABLE2 B
WHERE A.NUMBER = B.NUMBER