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.
Related
my Query ended with the Error "ora-00933 sql command not properly ended"
The Query:
create table tmp_cleaner
as (
SELECT dd.bigtriggerid
FROM documentdata dd
inner join ipl_bigtrigger bt on dd.bigtriggerid = bt.triggerid
inner join documentinfo di on dd.bigtriggerid = di.bigtriggerid
where bt.processed = 'T'
and di.status in (1, 2)
and bt.processdatetime <= add_months(sysdate, -3));
Delete FROM documentdata where exists (select bigtriggerid from tmp_cleaner where bigtriggerid = documentdata.bigtriggerid);
Error in Line 9. (last line)
ora-00933 sql command not properly ended
Where is my mistake? should i use trunc with date?
I tried to put the Join-Operators in ()
There's nothing wrong with that code.
Sample tables:
SQL> create table documentdata as select 1 bigtriggerid from dual;
Table created.
SQL> create table ipl_bigtrigger as select 1 triggerid, 'T' processed, date '2022-02-25' processdatetime from dual;
Table created.
SQL> create table documentinfo as select 1 bigtriggerid, 1 status from dual;
Table created.
Your query, as is:
SQL> CREATE TABLE tmp_cleaner
2 AS
3 (SELECT dd.bigtriggerid
4 FROM documentdata dd
5 INNER JOIN ipl_bigtrigger bt ON dd.bigtriggerid = bt.triggerid
6 INNER JOIN documentinfo di ON dd.bigtriggerid = di.bigtriggerid
7 WHERE bt.processed = 'T'
8 AND di.status IN (1, 2)
9 AND bt.processdatetime <= ADD_MONTHS (SYSDATE, -3));
Table created.
SQL> select * from tmp_cleaner;
BIGTRIGGERID
------------
1
SQL>
Could you provide some context? Where did you run that piece of code?
There's nothing wrong with delete either (apart from the fact that you're using a new table in the subquery; shouldn't that be tmp_cleaner you've just created?):
SQL> Delete FROM documentdata
2 where exists (select bigtriggerid
3 from tmp_cleaner -- tmp_loeschbigtrigger
4 where bigtriggerid = documentdata.bigtriggerid);
1 row deleted.
SQL>
I have a Query where there is number datatype column. In case of empty resultset O/P is blank. I want 0 in that case.
My query is
select nvl(infodata,0)
from table1
where group_id = 111
and appid in (select max(id)
from table1, table2
where status = 'A');
Now my inner query is returning null in that case. NVL seems to be not working on infodata column. Please help
Outcome of such a query is no rows selected.
For example (based on Scott's EMP and DEPT tables as I don't have yours, and you didn't post test case), this query returns nothing:
SQL> select e.deptno
2 from emp e
3 where e.ename = 'Littlefoot';
no rows selected
If it is used as a subquery, the result is equal to what you currently have:
SQL> select nvl(d.dname, 'x') result
2 from dept d
3 where d.deptno in (select e.deptno
4 from emp e
5 where e.ename = 'Littlefoot'
6 );
no rows selected
But, if you apply aggregation (see line #1), then you'd get what you wanted:
SQL> select nvl(max(d.dname), 'x') result
2 from dept d
3 where d.deptno in (select e.deptno
4 from emp e
5 where e.ename = 'Littlefoot'
6 );
RESULT
--------------
x
As I said: it works on my test case; might, or might not on yours. If you post sample data, we'd have something to work with.
I wrote a SELECT performing a UNION and in each UNION part using some JOINs. The tables, which are joined have partly the same column identifiers.
And if a "SELECT *" is performed, ORACLE decides to display the internal column names instead of the "real" column names.
To show the effect I created two tables (with partly similar column identifiers, "TID" and "TNAME") and filled them with some data:
create table table_one (tid number(10), tname varchar2(10), t2id number(10));
create table table_two (tid number(10), tname varchar2(10));
insert into table_two values (1,'one');
insert into table_two values (2,'two');
insert into table_two values (3,'three');
insert into table_one values (1,'eins',1);
insert into table_one values (2,'zwei',2);
insert into table_one values (3,'drei',3);
The I SELECTED the columns afterwards with the following statement:
select *
from table_one
inner join table_two on table_two.tid = table_one.t2id
where table_one.tid = 1
union
select *
from table_one
inner join table_two on table_two.tid = table_one.t2id
where table_one.tid = 2;
And got this confusing result:
QCSJ_C000000000300000 QCSJ_C000000000300002 T2ID QCSJ_C000000000300001 QCSJ_C000000000300004
1 eins 1 1 one
2 zwei 2 2 two
When the statement is written with tablenames to specify the columns, everything works as I expected:
select table_one.* , table_two.*
from table_one
inner join table_two on table_two.tid = table_one.t2id
where table_one.tid = 1
minus
select *
from table_one
inner join table_two on table_two.tid = table_one.t2id
where table_one.tid = 2;
TID TNAME T2ID TID TNAME
1 eins 1 1 one
2 zwei 2 2 two
Can anybody explain that?
I expanded my tests with two more tables to prevent double usage of table in the statement:
create table table_3 (tid number(10), tname varchar2(10), t4id number(10));
create table table_4 (tid number(10), tname varchar2(10));
insert into table_4 values (1,'one');
insert into table_4 values (2,'two');
insert into table_4 values (3,'three');
insert into table_3 values (1,'eins',1);
insert into table_3 values (2,'zwei',2);
insert into table_3 values (3,'drei',3);
select *
from table_one
inner join table_two on table_two.tid = table_one.t2id
where table_one.tid = 1
union
select *
from table_3
inner join table_4 on table_4.tid = table_3.t4id
where table_3.tid = 2;
select *
from table_one
inner join table_two on table_two.tid = table_one.t2id
where table_one.tid = 1
union
select *
from table_3
inner join table_4 on table_4.tid = table_3.t4id
where table_3.tid = 2;
The result is the same. Oracle uses internal identifiers.
According to Oracle (DocId 2658003.1), this happens when three conditions are met:
ANSI join
UNION / UNION ALL
the same table appears more than once in the query
Aparently, "QCSJ_C" is used internally when Oracle transforms ANSI style joins.
EDIT:
Found a minimal example:
SELECT * FROM dual d1 JOIN dual d2 ON d1.dummy=d2.dummy
UNION
SELECT * FROM dual d1 JOIN dual d2 ON d1.dummy=d2.dummy;
QCSJ_C000000000300000 QCSJ_C000000000300001
X X
It can be fixed by either using non-ANSI join syntax:
SELECT * FROM dual d1, dual d2 WHERE d1.dummy=d2.dummy
UNION
SELECT * FROM dual d1, dual d2 WHERE d1.dummy=d2.dummy;
DUMMY DUMMY_1
X X
Or, preferably by using column names instead of *:
SELECT d1.dummy, d2.dummy FROM dual d1 JOIN dual d2 ON d1.dummy=d2.dummy
UNION
SELECT d1.dummy, d2.dummy FROM dual d1 JOIN dual d2 ON d1.dummy=d2.dummy;
DUMMY DUMMY_1
X X
Interesting!
However, I would never use a set operator (UNION, UNION ALL, INTERSECT, MINUS) together with an asterisk (*).
The order of columns can change, maybe not by you but by somebody doing maintenance on the database, or by migrating your database to a new system using export/import, etc. Simple example:
CREATE TABLE t (a INT, b INT, c INT);
SELECT * FROM t;
A B C
ALTER TABLE t MODIFY b INVISIBLE;
ALTER TABLE t MODIFY b VISIBLE;
SELECT * FROM t;
A C B
I've got a table as follows
Table1
ID Name Tag
-----------------
1 N1 2.1
2 N2 3.5
3 N1 3.5
4 N3 8.1
I create a new table Table2 with ID and Name (unique constraint) and I want to insert Table1's contents into Table2 avoiding duplicates, in the sense that I want only 1, 2 and 4 from Table1 in Table2.
I've tried this but it doesn't seem to work and I get the unique constraint error (ORACLE SQL)
INSERT INTO TABLE2 (ID, NAME)
SELECT ID, NAME
FROM TABLE1
WHERE NAME NOT IN (SELECT NAME FROM TABLE2);
Please can someone point me in the right direction?
Sorry for not making myself clear. Table2 is a brand new table. I want the first values inserted, the following duplicates should be ignored. So in my case, N1, N2 get inserted, N1 is dupe so it is ignored, N3 is inserted
OK - from your description, I understand table t2 is currently empty, and you want to copy the rows where id is in (1, 2, 4) from table t1 to table t2.
Why your code fails:
You seem to believe that the condition is applied to the first row in t1, it passes so it is inserted into t2, then the condition is applied to the second row in t1 (using what is already inserted in t2), etc. - and you don't understand why there is any attempt to insert ALL the rows from t1 into t2. Why doesn't the third row fail the WHERE clause?
Good question! The reason is that operations are done on a SET basis. The WHERE condition uses table t2 AS IT WAS before the INSERT operation began. So for ALL rows, the WHERE clause compares to an empty table t2.
How to fix this... Decide which id you want to add when there are duplicate names. For example, one way to get the result you said you wanted is to select MIN(id) for each name. Moreover, you still want to check if the name exists in t2 already (since you may do this again in the future, when t2 is already partially populated).
insert into t2 ( id, name )
select min(id), name
from t1
where name not in (select name from t2)
group by name
;
You can try it bother....!
Insert into tb2(Field1, Field2)
SELECT Field1, Field2
FROM tb1
WHERE NOT EXISTS (SELECT Field1 FROM tb1) ;
This is how I understood the question:
SQL> create table table2
2 (id number,
3 name varchar2(2),
4 tag number,
5 constraint pk_t2 primary key (id, name)
6 );
Table created.
SQL>
SQL> insert into table2 (id, name, tag)
2 with test (id, name, tag) as
3 (select 1, 'N1', 2.1 from dual union
4 select 2, 'N2', 3.5 from dual union
5 select 3, 'N1', 3.5 from dual union
6 select 4, 'N3', 8.1 from dual
7 )
8 select min(id), name, max(tag)
9 from test
10 group by name;
3 rows created.
SQL>
SQL> select * from table2 order by id;
ID NA TAG
---------- -- ----------
1 N1 3,5
2 N2 3,5
4 N3 8,1
SQL>
When we need to unique any two or more column we have to create unique index.
Run this query
ALTER TABLE TABLE2 ADD UNIQUE unique_index( id, name);
and then
INSERT INTO TABLE2 (id,name,tag) VALUES(1, "N1", 3.5 )
ON DUPLICATE KEY UPDATE tag=3.5
this will also help to update new tag
Try to check if the id and name from Table1 is doesn't exist in Table2, if then insert.
If the unique constraint on TABLE2 is a composite key then run this:
INSERT INTO TABLE2 (ID, NAME)
SELECT A.ID, A.NAME
FROM TABLE1 A
WHERE NOT EXISTS (SELECT NULL FROM TABLE2 B WHERE A.ID=B.ID AND A.NAME=B.NAME);
If there are two unique constraints; one on the id, and the other on the name then run this instead:
INSERT INTO TABLE2 (ID, NAME)
SELECT A.ID, A.NAME
FROM TABLE1 A
WHERE NOT EXISTS (SELECT NULL FROM TABLE2 B WHERE A.ID=B.ID OR A.NAME=B.NAME);
ORACLE, in case you need to get values from 2 different tables.
below example,i use an increment case.
INSERT INTO TABLE1
(INDEX, REMARKS, NAME, AGE)
(SELECT (SELECT colescs(MAX(INDEX),0) FROM TABLE1)+1,
'any remarks',
t2.NAME, t2,age from TABLE2 t2 where t2.name = 'apple')
explanation
match below numbers (1)-(1), (2)-(2) ...
INSERT INTO TABLE1
(INDEX, //index increment (1)
REMARKS, //hard code (2)
NAME, //from table2 (3)
AGE) //from table2 (4)
(SELECT // this part is to get values from another table
(SELECT colescs(MAX(INDEX),0) FROM TABLE1)+1, //increment (1)
'any remarks', //hard code value (2)
t2.NAME, //from table2 (3)
t2,age //from table2 (4)
from TABLE2 t2 where t2.name = 'apple') //condition for table2
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