Sql 从Oracle的另一个表更新

表1

表2

Tripid  sequence Pattern
  1       1       
  1       2
  1       3
  2       1   
  2       2 

我正在尝试更新表1的模式，最终结果应该是：

Tripid Pattern
  1      A
  2      B

我使用的代码：

Tripid  sequence Pattern
  1       1        A
  1       2        A
  1       3        A
  2       1        B
  2       2        B

Oracle数据库错误：ORA-01427:单行子查询返回多行

如何在oracle 10g中正确执行此操作？

您可以使用此语句

查询：

update table1
set table1.pattern = 
    (select pattern from table2 where table1.tripid = table2.tripid) 
where exists 
    (select pattern from table2 where table1.tripid = table2.tripid)

select * from t1

| TRIPID | SEQ | PATTERN |
|--------|-----|---------|
|      1 |   1 |  (null) |
|      1 |   2 |  (null) |
|      1 |   3 |  (null) |
|      2 |   1 |  (null) |
|      2 |   2 |  (null) |

merge into t1
using t2
on (t1.tripid = t2.tripid)
when matched then update
set pattern = t2.pattern

select * from t1

：

update table1
set table1.pattern = 
    (select pattern from table2 where table1.tripid = table2.tripid) 
where exists 
    (select pattern from table2 where table1.tripid = table2.tripid)

select * from t1

| TRIPID | SEQ | PATTERN |
|--------|-----|---------|
|      1 |   1 |  (null) |
|      1 |   2 |  (null) |
|      1 |   3 |  (null) |
|      2 |   1 |  (null) |
|      2 |   2 |  (null) |

merge into t1
using t2
on (t1.tripid = t2.tripid)
when matched then update
set pattern = t2.pattern

select * from t1

查询：

update table1
set table1.pattern = 
    (select pattern from table2 where table1.tripid = table2.tripid) 
where exists 
    (select pattern from table2 where table1.tripid = table2.tripid)

select * from t1

| TRIPID | SEQ | PATTERN |
|--------|-----|---------|
|      1 |   1 |  (null) |
|      1 |   2 |  (null) |
|      1 |   3 |  (null) |
|      2 |   1 |  (null) |
|      2 |   2 |  (null) |

merge into t1
using t2
on (t1.tripid = t2.tripid)
when matched then update
set pattern = t2.pattern

select * from t1

查询：

update table1
set table1.pattern = 
    (select pattern from table2 where table1.tripid = table2.tripid) 
where exists 
    (select pattern from table2 where table1.tripid = table2.tripid)

select * from t1

| TRIPID | SEQ | PATTERN |
|--------|-----|---------|
|      1 |   1 |  (null) |
|      1 |   2 |  (null) |
|      1 |   3 |  (null) |
|      2 |   1 |  (null) |
|      2 |   2 |  (null) |

merge into t1
using t2
on (t1.tripid = t2.tripid)
when matched then update
set pattern = t2.pattern

select * from t1

：

update table1
set table1.pattern = 
    (select pattern from table2 where table1.tripid = table2.tripid) 
where exists 
    (select pattern from table2 where table1.tripid = table2.tripid)

select * from t1

| TRIPID | SEQ | PATTERN |
|--------|-----|---------|
|      1 |   1 |  (null) |
|      1 |   2 |  (null) |
|      1 |   3 |  (null) |
|      2 |   1 |  (null) |
|      2 |   2 |  (null) |

merge into t1
using t2
on (t1.tripid = t2.tripid)
when matched then update
set pattern = t2.pattern

select * from t1

---

也许tripid在表2中不是唯一的

这在您的示例中，但它在您的真实数据中是唯一的吗

| TRIPID | SEQ | PATTERN |
|--------|-----|---------|
|      1 |   1 |       A |
|      1 |   2 |       A |
|      1 |   3 |       A |
|      2 |   1 |       B |
|      2 |   2 |       B |

返回：

DROP  table table1;
create table table1(tripid number, sequence number, pattern  CHAR(1));
insert into table1 values (1,1,null);
insert into table1 values (1,2,null);
insert into table1 values (1,3,null);
insert into table1 values (2,1,null);
insert into table1 values (2,2,null);

DROP  table table2;
create table table2(tripid number, pattern CHAR(1));
insert into table2 values (1,'A');
insert into table2 values (2,'B');

commit;

select table2.tripid, table2.pattern from table2,table1 where table1.tripid = table2.tripid;


update table1
set table1.pattern = 
    (select pattern from table2 where table1.tripid = table2.tripid) 
where exists 
    (select pattern from table2 where table1.tripid = table2.tripid);

commit;

select * from table1;

这证明了有了好的数据，Oracle（和您的查询）可以完美地工作

---

Christian

为什么来自另一个表的更新在oracle中不起作用？？