I want to update 1 field of the last 2 rows of a table. So I need a subquery.
Both sql works - how can I combine these 2 SQL commands?
select command (works, last 2 rows):
SELECT * FROM (select * from mytable WHERE id='62741' ORDER BY lfdnr DESC) mytable2 WHERE rownum <= 2;
Result:
LFDNR ID M2
361782 62741 8,5
361774 62741 8,6
Update (?, exists, in, merge ?)
UPDATE mytable set m2='8,4' WHERE EXISTS (select * from mytable WHERE id='62741' and rownum <=2 ORDER BY lfdnr DESC);
Result:
Fehlerbericht -
SQL-Fehler: ORA-00907: missing right parenthesis
00907. 00000 - "missing right parenthesis"
*Cause:
*Action:
Thank you for helping me!
Michael
You could use rowid pseudocolumn:
update mytable set m2 = '8, 4'
where rowid in (select rowid
from (
select rowid, row_number() over (order by lfdnr desc) rn
from mytable where id = '62741')
where rn <= 2 )
Test:
create table mytable (id varchar2(5), lfdnr number(5), m2 varchar2(10));
insert into mytable values ('62705', 1, 'abc');
insert into mytable values ('62741', 2, 'xyz');
insert into mytable values ('62741', 3, 'qwe');
insert into mytable values ('62741', 4, 'rty');
ID LFDNR M2
----- ------ ----------
62705 1 abc
62741 2 xyz
62741 3 8, 4
62741 4 8, 4
Related
Just wondering why the following select isn't working:
SELECT
A.FIELD1
, (SELECT PCN FROM (select B.PRIORITY, B.PCN
from
TABLE2 B
WHERE B.CUST= A.CUST
ORDER BY B.PRIORITY)
WHERE ROWNUM = 1) AS PCN
FROM TABLE1 A;
ERROR at line 2: ORA-00904: "A"."CUST": invalid identifier
Important to mention:
TABLE1 has as fields FIELD1, CUST.
TABLE2 has as fields PCN, PRIORITY, CUST.
Thanks in advance.
Your query shouldn't give you that error message, on when you remove the outer qiery this would happen
CREATE tABLE TABLE1 (FIELD1 int, CUST int)
INSERT INTO TABLE1 VALUES(1,1)
1 rows affected
CREATE TABLE TABLE2 (PCN int, PRIORITY int, CUST int)
INSERT INTO TABLE2 VALUES (1,1,1)
1 rows affected
SELECT
A.FIELD1
, (SELECT PCN FROM (select B.PRIORITY, B.PCN
from
TABLE2 B
WHERE B.CUST= A.CUST
ORDER BY B.PRIORITY)
WHERE ROWNUM = 1) AS PCN
FROM TABLE1 A;
FIELD1
PCN
1
1
fiddle
You can't nest inline selects (more than one level) without losing the ability of the inner nested selects being able to reference the parent block. So your query on TABLE2 cannot see the columns from TABLE1 because of this nesting.
Try this:
SELECT a.field1,
pcn.pcn
FROM table1 a,
(SELECT b.cust,
b.priority,
b.pcn,
ROW_NUMBER() OVER (PARTITION BY b.cust ORDER BY b.priority DESC) seq
FROM table2 b) pcn
WHERE a.cust = pcn.cust(+)
AND pcn.seq(+) = 1
That will work well for report queries. If you end up adding a filter on a specific customer, then you would be better off using OUTER APPLY if you have a recent-enough version of Oracle that supports that.
You could try this:
SELECT
A.FIELD1
, (SELECT B.PCN
from
TABLE2 B
WHERE B.CUST= A.CUST
ORDER BY B.PRIORITY
FETCH FIRST 1 ROWS ONLY) AS PCN
FROM TABLE1 A;
FETCH FIRST 1 ROWS ONLY gets you the first ordered record. Works on 12c and up and supports nesting, and no 2nd subquery needed.
Yet another option might be a CTE.
Sample data:
SQL> with
2 table1 (field1, cust) as
3 (select 1, 100 from dual union all
4 select 2, 200 from dual
5 ),
6 table2 (pcn, priority, cust) as
7 (select 10, 1, 100 from dual union all
8 select 20, 2, 100 from dual union all
9 select 30, 1, 200 from dual
10 ),
Query begins here. Rank rows by priority, and then fetch the ones that rank as the highest (line #20):
11 temp as
12 (select a.field1,
13 b.pcn,
14 rank() over (partition by a.field1 order by b.priority desc) rnk
15 from table1 a join table2 b on a.cust = b.cust
16 )
17 select field1,
18 pcn
19 from temp
20 where rnk = 1;
FIELD1 PCN
---------- ----------
1 20
2 30
SQL>
You may use first aggregate function to achieve the same (assuming that you have completely deterministic order by) functionality without nested subquery:
select
a.field1
, (
select max(b.pcn) keep(dense_rank first order by b.priority)
from table2 b
where b.cust = a.cust
) as pcn
from table1 a
which for this sample data
insert into table1 values(1,1);
insert into table1 values(2,2);
insert into table2 values(1,1,1);
insert into table2 values(2,2,1)
returns
FIELD1
PCN
1
1
2
(null)
SQL fiddle
I have created a temp table with pivot as below:
INSERT into A_temp_table(PER_KEY, LANDLINE, FAX, MOBILE)
select * from
(select PER_KEY, TEL_NUM, from ABC.V_PER_TEL)
pivot(max(TEL_NUM) for TEL_TYPE_DESC in ('LANDLINE', 'FAX', 'MOBILE'));
After this I am fetching the data using joins as below:
SELECT P.PERSON_KEY,
P.FIRST_NAME,
P.MIDDLE_NAME,
P.LAST_NAME,
PT.LANDLINE,
PT.FAX,
PT.MOBILE,
FROM ABC.V_PER P
LEFT OUTER JOIN A_temp_table PT ON P.PER_KEY=PT.PER_KEY
My Question is:
Can I replace the temp table used in join with the select statement directly.
Like below:
SELECT P.PERSON_KEY,
P.FIRST_NAME,
P.MIDDLE_NAME,
P.LAST_NAME,
PT.LANDLINE,
PT.FAX,
PT.MOBILE,
FROM ABC.V_PER P
LEFT OUTER JOIN (select * from
(select PER_KEY, TEL_NUM, from ABC.V_PER_TEL)
pivot(max(TEL_NUM) for TEL_TYPE_DESC in ('LANDLINE', 'FAX', 'MOBILE'))) PT ON P.PER_KEY=PT.PER_KEY
But, in doing the above step My code is not running.
Is there any other way to remove temp table use, and why my way is not working.
Please help,
The problem is that you need to use alias for the columns from the PIVOT; for example:
create table testPivot(v varchar2(10), n number);
insert into testPivot values ('A', 10);
insert into testPivot values ('A', 10);
insert into testPivot values ('B', 10);
This will give error:
SQL> select A
2 from (
3 select *
4 from testPivot
5 pivot(max(n) for v in ('A', 'B'))
6 );
select A
*
ERROR at line 1:
ORA-00904: "A": invalid identifier
This will work:
SQL> select A
2 from (
3 select *
4 from testPivot
5 pivot(max(n) for v in ('A' as A, 'B' as B))
6 );
A
----------
10
I am trying to update two columns from select statement, but I am getting error message that says
ORA-00927: missing equal sign
Please, can anyone tell me why ?
UPDATE table1 a
SET co1 ,co2 = (SELECT COUNT (*),
sum(cost)/4
FROM table2 b
WHERE a.customer_id = b.cust_info_customer_id
AND tariff_info = 2);
Since you didn't provide any input:
create table table1(
co1 number,
co2 number,
customer_id number
)
insert into table1 values (1,1, 1)
select * from table1
CO1 CO2 CUSTOMER_ID
-------------------
1 1 1
UPDATE table1 a
SET co1 = (
with table2 as (
select level cost, 1 cust_info_customer_id from dual connect by rownum < 5
)
SELECT COUNT (*)
FROM table2 b
WHERE a.customer_id = b.cust_info_customer_id
)
, co2 = (
with table2 as (
select level cost, 1 cust_info_customer_id from dual connect by rownum < 5
)
SELECT sum(cost)/4
FROM table2 b
WHERE a.customer_id = b.cust_info_customer_id
)
select * from table1
CO1 CO2 CUSTOMER_ID
-------------------
4 2.5 1
I am new to Oracle technology. Earlier I posted 2 posts for the same issue due to lack of understanding the requirement.
Table 1:
MSGID
-----
1,2,3
2,3
4
null
null
Table 2:
MID MSGDESC
---- -------
1 ONE
2 TWO
3 THREE
4 FOUR
Expected output:
XCOL DESC
----- -----
1,2,3 ONE,TWO,THREE
2,3 TWO,THREE
4 FOUR
I am not able to fulfil this requirement. Please provide me one solution.
Note: tables don't have any unique or primary key values. Table 1 has 5000 records and table 2 only has 80 records with descriptions.
create table Table1 (MSGID varchar2(100));
insert into Table1 values ('1,2,3');
insert into Table1 values ('2,3');
insert into Table1 values ('4');
insert into Table1 values (null);
insert into Table1 values (null);
create table Table2 (MID varchar2(100), MSGDESC varchar2(100));
insert into Table2 values ('1','ONE');
insert into Table2 values ('2','TWO');
insert into Table2 values ('3','THREE');
insert into Table2 values ('4','FOUR');
select
msgid as xcol,
"DESC",
col1, col2, ..., col12
from
Table1
left join (
select
msgid,
wm_concat(msgdesc) as "DESC"
from
(
select
msgid,
msgdesc
from
(select distinct msgid from Table1 where ...)
cross join (
select level as occ from dual connect by level <= 100)
)
left join Table2
on mid = regexp_substr(msgid, '[^,]+', 1, occ)
where
occ <= regexp_count(msgid, ',') + 1
order by msgid, occ
)
group by msgid
) using (msgid)
I have the following code that works fine in MS SQL Server:
delete grp
from grp
left join my_data
on grp.id1 = my_data.id1
and grp.id2 = my_data.id2
and grp.id3 = my_data.id3
and grp.id4 = my_data.id4
where my_data.id1 is NULL
Basically, I want to delete all occurrence that can be found in grp and don't have any equivalence in my_data. Sadly, it doesn't work in Oracle 10g. I tried using the old syntax for left join (+) but it doesn't work either. Like this:
delete grp
from grp,
my_data
where grp.id1 = my_data.id1 (+)
and grp.id2 = my_data.id2 (+)
and grp.id3 = my_data.id3 (+)
and grp.id4 = my_data.id4 (+)
and my_data.id1 is NULL
A IN clause would works if I didn't have multiple keys but I don't see how I could use it with my data. So, what is the alternative?
Shannon's solution is the way to go: use the operator NOT IN (or NOT EXISTS).
You can however delete or update a join in Oracle, but the synthax is not the same as MS SQL Server:
SQL> DELETE FROM (SELECT grp.*
2 FROM grp
3 LEFT JOIN my_data ON grp.id1 = my_data.id1
4 AND grp.id2 = my_data.id2
5 AND grp.id3 = my_data.id3
6 AND grp.id4 = my_data.id4
7 WHERE my_data.id1 IS NULL);
2 rows deleted
Additionally, Oracle will only let you update a join if there is no ambiguity as to which base row will be accessed by the statement. In particular, Oracle won't risk an update or a delete (the statement will fail) if there is a possibility that a row may appear twice in the join. In this case, the delete will only work if there is a UNIQUE constraint on my_data(id1, id2, id3, id4).
Tables and data:
SQL> create table grp (id1 number null, id2 number null, id3 number null, id4 number null);
Table created.
SQL> create table my_data (id1 number null, id2 number null, id3 number null, id4 number null);
Table created.
SQL> insert into grp values (1, 2, 3, 4);
1 row created.
SQL> insert into grp values (10, 20, 30, 40);
1 row created.
SQL> insert into grp values (1, 2, 30, 40);
1 row created.
SQL> insert into my_data values (1, 2, 3, 4);
1 row created.
SQL> commit;
Commit complete.
Using in. Note Do not use if the IDs in the subquery can be null. Not in of null never returns true.
SQL> delete grp where (id1, id2, id3, id4) not in (select id1, id2, id3, id4 from my_data);
2 rows deleted.
SQL> select * from grp;
ID1 ID2 ID3 ID4
---------- ---------- ---------- ----------
1 2 3 4
Using exists
SQL> rollback;
Rollback complete.
SQL> delete grp where not exists (select * from my_data where grp.id1 = my_data.id1 and grp.id2 = my_data.id2 and grp.id3 = my_data.id3 and grp.id4 = my_data.id4);
2 rows deleted.
SQL> select * from grp;
ID1 ID2 ID3 ID4
---------- ---------- ---------- ----------
1 2 3 4
SQL>
If you want to ensure there is no ambiguity in what's being deleted, you could change Vincent's solution to:
delete from grp where rowid in
(
select
grp.rowid
from
grp left outer join my_data on
grp.id1 = my_data.id1
and grp.id2 = my_data.id2
and grp.id3 = my_data.id3
and grp.id4 = my_data.id4
where
my_data.id1 is NULL
)
Either Vincent's answer https://stackoverflow.com/a/3675205 does not work at all, or it does not work in Oracle 12c. That answer should be improved by specifying the lowest or highest version of Oracle where this works. The proof:
SELECT * FROM v$version where banner like 'Oracle%';
/*
Oracle Database 12c Standard Edition Release 12.2.0.1.0 - 64bit Production
*/
create table a (id int);
create table b (id int);
insert into a select 1 from dual union select 2 from dual;
insert into b select 1 from dual union select 2 from dual union select 3 from dual;
select * from a right join b on b.id = a.id;
/*
1 1
2 2
null 3
*/
delete from (
select b.*
from b
inner join a on a.id = b.id
)
/*
Error at Command Line : 7 Column : 13
Error report -
SQL Error: ORA-01752: cannot delete from view without exactly one key-preserved table
01752. 00000 - "cannot delete from view without exactly one key-preserved table"
*Cause: The deleted table had
- no key-preserved tables,
- more than one key-preserved table, or
- the key-preserved table was an unmerged view.
*Action: Redefine the view or delete it from the underlying base tables.
*/
delete from b
where rowid in (
select b.rowid
from b
inner join a on a.id = b.id
)
/*
2 rows deleted.
*/
select * from a right join b on b.id = a.id
/*
null 3
*/
drop table a;
drop table b;
Bottom line is, use WHERE ROWID IN () at least in 12c.
I can't add a comment because it need 50 reps,so I add a answer here.
I tested Vincent's delete from query, that syntax can't let you delete what you want,at least it's not a common use for all the delete join cases.
At first I create a table using oracle default user scott:
create table emp1 as select * from emp where sal<2000;
I want to delete the records from emp where empno in emp1(just a simple test),so I used this delete from query:
delete from (select a.* from emp a join emp1 b on a.empno=b.empno);
No matter what the table or join order is,left join or inner join,no matter what where clause I use,the sql will delete the corresponding records in emp1.
So I think this delete from query can not let you delete from a specified table.
Loop a cursor will be a better way for these cases.