CODEWITHSUNDEEP
sqloracle-databasesql-update
Muhd
Muhd

Reputation: 25566

Update a table with data from another table

Table 1:

id    name    desc
-----------------------
1     a       abc
2     b       def
3     c       adf

Table 2:

id    name    desc
-----------------------
1     x       123
2     y       345

In oracle SQL, how do I run an sql update query that can update Table 1 with Table 2's name and desc using the same id? So the end result I would get is

Table 1:

id    name    desc
-----------------------
1     x       123
2     y       345
3     c       adf

Question is taken from update one table with data from another, but specifically for oracle SQL.

Upvotes: 334

Views: 1393013

Answers (8)

Chris Saxon
Chris Saxon

Reputation: 9765

Oracle Database 23ai has added direct joins for update and delete:

create table t1 (
  c1 int, c2 int
);
create table t2 (
  c1 int, c2 int
);

insert into t1 values ( 1, 1 ), ( 2, 2 );
insert into t2 values ( 1, 42 );

select * from t1;

        C1         C2
---------- ----------
         1          1
         2          2

update t1
set    t1.c2 = t2.c2
from   t2
where  t1.c1 = t2.c1;

select * from t1;

        C1         C2
---------- ----------
         1         42
         2          2

delete t1
from   t2
where  t1.c1 = t2.c1;

select * from t1;

        C1         C2
---------- ----------
         2          2

Upvotes: 4

ant
ant

Reputation: 111

Here seems to be an even better answer with 'in' clause that allows for multiple keys for the join:

update fp_active set STATE='E', 
   LAST_DATE_MAJ = sysdate where (client,code) in (select (client,code) from fp_detail
  where valid = 1) ...

The full example is here: http://forums.devshed.com/oracle-development-96/how-to-update-from-two-tables-195893.html - from web archive since link was dead.

The beef is in having the columns that you want to use as the key in parentheses in the where clause before 'in' and have the select statement with the same column names in parentheses. where (column1,column2) in ( select (column1,column2) from table where "the set I want" );

Upvotes: 10

Adrian
Adrian

Reputation: 8485

Try this:

MERGE INTO table1 t1
USING
(
-- For more complicated queries you can use WITH clause here
SELECT * FROM table2
)t2
ON(t1.id = t2.id)
WHEN MATCHED THEN UPDATE SET
t1.name = t2.name,
t1.desc = t2.desc;

Upvotes: 263

Avila Theresa
Avila Theresa

Reputation: 27

BEGIN
For i in (select id, name, desc from table2) 
LOOP
Update table1 set name = i.name, desc = i.desc where id = i.id and (name is null or desc is null);
END LOOP;
END;

Upvotes: -2

Pau Karr
Pau Karr

Reputation: 265

Update table set column = (select...)

never worked for me since set only expects 1 value - SQL Error: ORA-01427: single-row subquery returns more than one row.

here's the solution:

BEGIN
For i in (select id, name, desc from table1) 
LOOP
Update table2 set name = i.name, desc = i.desc where id = i.id;
END LOOP;
END;

That's how exactly you run it on SQLDeveloper worksheet. They say it's slow but that's the only solution that worked for me on this case.

Upvotes: 15

Jim P
Jim P

Reputation: 571

If your table t1 and it's backup t2 have many columns, here's a compact way to do it.

In addition, my related problem was that only some of the columns were modified and many rows had no edits to these columns, so I wanted to leave those alone - basically restore a subset of columns from a backup of the entire table. If you want to just restore all rows, skip the where clause.

Of course the simpler way would be to delete and insert as select, but in my case I needed a solution with just updates.

The trick is that when you do select * from a pair of tables with duplicate column names, the 2nd one will get named _1. So here's what I came up with:

  update (
    select * from t1 join t2 on t2.id = t1.id
    where id in (
      select id from (
        select id, col1, col2, ... from t2
        minus select id, col1, col2, ... from t1
      )
    )
  ) set col1=col1_1, col2=col2_1, ...

Upvotes: -2

Justin Cave
Justin Cave

Reputation: 231651

This is called a correlated update

UPDATE table1 t1
   SET (name, desc) = (SELECT t2.name, t2.desc
                         FROM table2 t2
                        WHERE t1.id = t2.id)
 WHERE EXISTS (
    SELECT 1
      FROM table2 t2
     WHERE t1.id = t2.id )

Assuming the join results in a key-preserved view, you could also

UPDATE (SELECT t1.id, 
               t1.name name1,
               t1.desc desc1,
               t2.name name2,
               t2.desc desc2
          FROM table1 t1,
               table2 t2
         WHERE t1.id = t2.id)
   SET name1 = name2,
       desc1 = desc2

Upvotes: 646

Yahia
Yahia

Reputation: 70369

try

UPDATE Table1 T1 SET
T1.name = (SELECT T2.name FROM Table2 T2 WHERE T2.id = T1.id),
T1.desc = (SELECT T2.desc FROM Table2 T2 WHERE T2.id = T1.id)
WHERE T1.id IN (SELECT T2.id FROM Table2 T2 WHERE T2.id = T1.id);

Upvotes: 27

Related Questions