I have created a view that fills data from different tables. I used 10 select statements and combine the results of those select statements using UNION ALL.
I want to add primary key column to my view. because I have to create XML file using data in this view. so I need a primary key column for some process in my XML building application.
I have add rownum to all my select statements. But it returned duplicate ids. because rownum in each select statements start from 1.
Then I have created a sequence and tried use nextval . But I can't use sequence because my select statements has group by and order by.
Is there any way to do that ?
You can do a select over the union, for example:
SELECT rownum(),*
FROM (SELECT * FROM tableA UNION ALL SELECT * FROM tableB)
UPDATED
SELECT rownum, t.*
FROM (SELECT * FROM tableA UNION ALL SELECT * FROM tableB) t
Related
I am experimenting with a recursive CTE to split a string into multiple values. The data is then inserted into another table.
The following works in PostgreSQL:
CREATE TABLE test(data varchar(255));
WITH RECURSIVE
cte(genres) AS (SELECT 'apple,banana,cherry,date'),
split(genre,rest,genres) AS (
SELECT '', genres||',',genres FROM cte
UNION ALL
SELECT
substring(rest,0,position(',' IN rest)),
substring(rest,position(',' IN rest)+1),
genres
FROM split WHERE rest<>''
)
INSERT INTO test(data)
SELECT genre
FROM split;
However, the Oracle version:
CREATE TABLE test(data varchar(255));
WITH
cte(genres) AS (SELECT 'apple,banana,cherry,date' FROM dual),
split(genre,rest,genres) AS (
SELECT '', genres||',',genres FROM cte
UNION ALL
SELECT
substr(rest,1,instr(rest,',')-1),
substr(rest,instr(rest,',')+1),
genres
FROM split WHERE rest IS NOT NULL
)
INSERT INTO test(data)
SELECT genre
FROM split WHERE genre IS NOT NULL;
gives me the error message:
ORA-00928: missing SELECT keyword.
Now I’m pretty sure that I’ve got one, there between the INSERT and the following FROM.
If you comment out the INSERT, the rest of it will give the results. Elsewhere, I know that a simple INSERT … SELECT does work.
Is it something to do with the recursive CTE? How can I get this to work properly using a standard recursive CTE?
Using Oracle 18c in a Docker image. There is a fiddle here: https://dbfiddle.uk/?rdbms=oracle_18&fiddle=d24f3105634933af1b7072bded1dacdf .
An INSERT-SELECT means "INSERT" command first, then the SELECT part, and the WITH is part of the SELECT not the insert.
SQL> create table t ( x int );
Table created.
SQL> with blah as ( select 1 c from dual)
2 insert into t
3 select * from blah;
insert into t
*
ERROR at line 2:
ORA-00928: missing SELECT keyword
SQL> insert into t
2 with blah as ( select 1 c from dual)
3 select * from blah;
1 row created.
Wondering if there is a way to insert a row into a table from another, with exception of one column in the middle without specifying all the column name? I have 128 columns in the table.
I created a view to store the original records.
CREATE VIEW V_TXN_STG AS
SELECT * FROM TXN_STG;
In table TXN_STG, only one column BRN_CODE is changing.
Something like this doesn't work, because the column is not on the last, but somewhere middle of table structure.
INSERT INTO TXN_STG
SELECT v.*, 'BRN-001' AS BRN_CODE
FROM V_TXN_STG v;
I don't believe that this is possible without explicitly specifying the columns in your select.
first you have to get the columns:
SELECT listagg(column_name, ',') within group (order by column_name) columns
FROM all_tab_columns
WHERE table_name = 'AAA' --Table to insert too
and column_name <> 'B' -- column name you want to exclude
GROUP BY table_name;
Then insert that result on the first row:
insert into aaa(A,C) -- A,C is my result from above,I have excluded column B
select *
from (select 'a' A,'q' AMOUNT,'c' C from dual union all -- my sample data
select 'a','a','c' from dual union all
select 'a','b','c' from dual union all
select 'a','c','c' from dual union all
select 'a','d','c' from dual )
pivot
(
max(1)
for (AMOUNT) -- the column you want to remove from the sample data
IN ()
)
where 1=1
order by A;
I need to query many tables in A Oracle database in a single query for a typeahead function, which means I need to query for each keypress on a homepage.
select * from
(select * from table1
union all
select * from table2
union all
select * from table3
union all
select * from table4
)
where colume_name like '%xxx%'
All the union will result in a dataset of around 300000 records.
Is there anyway, this query can be optimized, so Oracle somehow keep the united dataset in a cache or temporary table that can be used for the next keypress?
As you said - you could create a (global) temporary table with on commit preserve rows option, store the result in there and use data during that session.
I am trying to join two tables together but the key in one table is formated like 'xxxxxx' and the key I am trying to join together in the second table is formated like '2222xxxxxx'. Is there a way I can either split the second column into two different columns to make the join, or join on only the last 6 numbers of column 2?
Notes: values are numeric. the '2222' is always the same 4 numbers.
Try this way:
select *
from table1 a
INNER JOIN table2 b
on a.fieldname = substr(b.fieldname, -6)
Here is the documentation for the SUBSTR Function in Oracle.
Know that this is a very bad design for your second table you should consider in separating this values in different columns.
EDIT
This comment from #Boneist "if there were 7 numbers after the first 4, not just 6?"
To fix this you should use: substr(b.fieldname, 5)
To separate that column on a select statement either you create a new column and update it values with the given substr or just add it in the select command.
On the select command:
select fielda, fieldb,
substr(b.fieldname, 1, 4) firstPartOfField,
substr(b.fieldname, 5) secondPartOfField
from tableb
To create another column it would be
alter table tableb add column newField number(6);
update tableb
set oldField = substr(b.fieldname,1,4),
newField = substr(b.fieldname,5);
I would suggest a slightly different approach:
If your column has varchar/char data type:
drop table tab1;
drop table tab2;
create table tab1(col char(30));
create table tab2(col char(30));
insert into tab1
select lpad(to_char(level), 6, '0') as val
from dual connect by level <=100 order by level;
insert into tab2
select '2222' || lpad(to_char(level), 6, '0') as val
from dual connect by level <=100 order by level;
create unique index ux_tab1 on tab1(col);
create unique index ux_tab2 on tab2(col);
select tab1.col, tab2.col
from tab1
join tab2
on '2222' || tab1.col = tab2.col;
-- check execution plan
explain plan for
select tab1.col, tab2.col
from tab1
join tab2
on '2222' || tab1.col = tab2.col;
select * from table(dbms_xplan.display);
If your column has number data type:
drop table tab1;
drop table tab2;
create table tab1(col number);
create table tab2(col number);
insert into tab1
select 100000 + level as val
from dual connect by level <=100 order by level;
insert into tab2
select 2222100000 + level as val
from dual connect by level <=100 order by level;
create unique index ux_tab1 on tab1(col);
create unique index ux_tab2 on tab2(col);
select tab1.col, tab2.col
from tab1
join tab2
on 2222000000 + tab1.col = tab2.col;
-- check execution plan
explain plan for
select tab1.col, tab2.col
from tab1
join tab2
on 2222000000 + tab1.col = tab2.col;
select * from table(dbms_xplan.display);
Using this approach Oracle will be able to use indexes for joining !
select * into tableA from dataA.
I have created a table tableA.
Next time,
insert * into tableA from dataB. it doesn't work. Because tableA is already exist.
I need insert data twice instead of unioning dataA and dataB.
select * into tableA from dataA.
Next,
INSERT INTO tableA(colum1,colum2)<--Not *
SELECT (colum1,colum2)
FROM B