When i try to execute a query, which is organised as the below example, it retrieves data..
select * from (
select col1, col2, col3, col4....coln
from TABLE_ONE left outer join TABLE_TWO
-- some conditions and group by clause
order by 1 asc
)
where rownum <=1000;
Again if I use Column alias in the ORDER BY clause col1, the query won't retrieve data.
Also If I use ORDER BY 4 instead of ORDER BY 1, the query wont return data...
select * from (
select col1, col2, col3, col4....coln
from TABLE_ONE left outer join TABLE_TWO
-- some conditions and group by clause
order by 4 asc
)
where rownum <=1000;
The whole issue revolves around the inner ORDER BY Clause and external ROWNUM condition..If I eliminate any of the two, the query works fine...I am not sure if indexes have some role to play in it...
high number of executions of specific types of queries which is using only rownum clause. For exam.
select ani, rowid from tbl_smschat_upuor where rownum<=:"SYS_B_0";
DB is having high number of executions of these type of queries and these when I m checking the execution plan for the same type of queries it is accessing the full table scan.
======================execution plan for above query 1000 rows selected. Execution Plan ---------------------------------------------------------- Plan hash value: 91289622 --------------------------------------------------------------------------------
I have requirement to create an XML structure through stored procedure. I need to Order some of the columns in ascending order before I format them into the xml structure. I am pretty novice to creating an output into XML format, but attached is the query I came up with (without order by). This works perfect, but now the requirement is to order by - cls_cd, and within cls_cd, again order by - cat_cd. I am not able to do this.
I have a requirement where I need to display a list of employees, performance rating and manager id. I want to display the employees first whose manager is as manager_id as input parameter. So lets say a manager logs in, he should see his reporters first and then the rest. How can I implement this in SQL? I am trying first clause with order by but not sure how to do that here.
I have got the following error while executing below Query.
ORA-01791 'Not a SELECTed expression'
select distinct sgbstdn_levl_code from sgbstdn,spriden where spriden_pidm = sgbstdn_pidm and spriden_id = '200076543' order by sgbstdn_term_code_eff desc;
The above Query is not working with Distinct & Order By clause are present and by joining two tables. I need the distinct values of levels in Descending order of Terms.
select col1, col2, col3, col4 from tab1, tab2, tab3 where conditions union
[Code]...
Now, the col4 is a date column and I have to order by the entire result sets on it. I know I can do it by (order by col4) or by (order by 4) at the end of the entire query.
But the problem is that, the output is coming in dd-Mon-yyyy (i.e 31-Nov-2012).
I want every output in dd/mm/yyyy format so I need to use to_char function.
But in that case, I cant use the order by clause, because in that case it is getting arranged by character i.e by 1,2,3,4,5 like this.
currently i m going through some dumps for my OCA-11g prep.I came across one sentence :A view cannot have an ORDER BY clause in the SELECT statement.well this statement is false and the explanation given was :
Query operations containing ORDER BY clause are also permitted, so long as the ORDER BY clause appears outside the parentheses.
The following is an example of what I mean: CREATE VIEW my_view AS (SELECT*FROM emp) ORDER BYempno.
but when i tried running the query like this :CREATE VIEW my_view AS SELECT*FROM emp ORDER BYempno ,it worked w/o giving parentheses.
I have a real problem with form, specifically one of its data blocks. In the order by property of the block i specify it to sort on a branch in ascending order(i tried descending as well) but for some reason the form ignores that and sorts it on the ROWNUM. I even removed the where clause, the order by clause and changed the query data source type to FROM clause and changed the data source name to pre-query. I then created the query string in the block's pre-query trigger and set query_data_source_name property to that query string and still the data in the block is not being sorted on the branch number but instead on the ROWNUM.
How to avoid sort operation by an order by clause without changing the sort area size.what hints or changes should be done in query so that order by clause work faster.
I came across situation where a Nullable column is not using index for 'order by' clause. I added Not Null condition in the 'where' condition but it wasn't useful. I don't wanted to make composite index with not nullable column or with constant or modify column to 'Not Null'
So I carried out test cases and during which I found that in one case the sql statement does 'fast full scan' for data access but does not use index for 'order by' sorting
here are the steps
Initially I kept the column Nullable
SQL> create sequence s5; Sequence created.
SQL> create table t5 as select s5.nextval id,a.* from dba_objects a where rownum<1001; Table created.
SQL> set pages 100 SQL> select column_name,nullable from user_tab_columns where table_name='T5';
Misses in library cache during parse: 1 Optimizer mode: ALL_ROWS Parsing user id: 5
Rows Row Source Operation ------- --------------------------------------------------- 1000 SORT ORDER BY (cr=16 pr=0 pw=0 time=4771 us) 1000 TABLE ACCESS FULL T5 (cr=16 pr=0 pw=0 time=1157 us)
Elapsed times include waiting on following events: Event waited on Times Max. Wait Total Waited ---------------------------------------- Waited ---------- ------------ SQL*Net message to client 68 0.00 0.00 SQL*Net message from client 68 49.49 49.72 ********************************************************************************
select /*+ index(t i5) */ * from t5 t where id is not null order by id
Misses in library cache during parse: 1 Optimizer mode: ALL_ROWS Parsing user id: 5
Rows Row Source Operation ------- --------------------------------------------------- 1000 TABLE ACCESS BY INDEX ROWID T5 (cr=150 pr=0 pw=0 time=5167 us) 1000 INDEX FULL SCAN I5 (cr=71 pr=0 pw=0 time=3141 us)(object id 4673065)
Elapsed times include waiting on following events: Event waited on Times Max. Wait Total Waited ---------------------------------------- Waited ---------- ------------ SQL*Net message to client 69 0.00 0.00 SQL*Net message from client 69 22.89 28.04
Now I modified the 'id' column to Not Null
SQL> alter table t5 modify id not null;
SQL> set pages 100 SQL> select column_name,nullable from user_tab_columns where table_name='T5';
COLUMN_NAME N ------------------------------ - ID N OWNER Y OBJECT_NAME Y SUBOBJECT_NAME Y OBJECT_ID Y DATA_OBJECT_ID Y OBJECT_TYPE Y CREATED Y LAST_DDL_TIME Y TIMESTAMP Y STATUS Y TEMPORARY Y GENERATED Y SECONDARY Y
Misses in library cache during parse: 1 Optimizer mode: ALL_ROWS Parsing user id: 5
Rows Row Source Operation ------- --------------------------------------------------- 1000 SORT ORDER BY (cr=16 pr=0 pw=0 time=2398 us) 1000 TABLE ACCESS FULL T5 (cr=16 pr=0 pw=0 time=1152 us)
Elapsed times include waiting on following events: Event waited on Times Max. Wait Total Waited ---------------------------------------- Waited ---------- ------------ SQL*Net message to client 68 0.00 0.00 SQL*Net message from client 68 37.74 37.91 ********************************************************************************
Misses in library cache during parse: 1 Optimizer mode: ALL_ROWS Parsing user id: 5
Rows Row Source Operation ------- --------------------------------------------------- 1000 TABLE ACCESS BY INDEX ROWID T5 (cr=150 pr=0 pw=0 time=4166 us) 1000 INDEX FULL SCAN I5 (cr=71 pr=0 pw=0 time=3142 us)(object id 4673065)
Elapsed times include waiting on following events: Event waited on Times Max. Wait Total Waited ---------------------------------------- Waited ---------- ------------ SQL*Net message to client 68 0.00 0.00 SQL*Net message from client 68 8.28 8.45
Misses in library cache during parse: 1 Optimizer mode: ALL_ROWS Parsing user id: 5
Rows Row Source Operation ------- --------------------------------------------------- 1000 SORT ORDER BY (cr=6 pr=0 pw=0 time=1342 us) 1000 INDEX FAST FULL SCAN I5 (cr=6 pr=0 pw=0 time=1093 us)(object id 4673065)
Elapsed times include waiting on following events: Event waited on Times Max. Wait Total Waited ---------------------------------------- Waited ---------- ------------ SQL*Net message to client 68 0.00 0.00 SQL*Net message from client 68 1.88 1.89
Questions are
1) Why adding 'where id is not null wasn't enough for the index to get used in 'order by'? 2) While we got 'fast full scan' why index wasn't used for 'order by' clause? 3) Do we need the indexed column in where clause for being used in 'order by clause' too? 4) Do we need 'order by' clause if we are selecting only the indexed column with sequence generated values?
Name Null Type --------------------------- -------- ------------- RPTNO NOT NULL NUMBER RPTDATE NOT NULL DATE RPTD_BY NOT NULL VARCHAR2(25) PRODUCT_ID NOT NULL NUMBER
describe rptbody
Name Null Type ------------- -------- ------------- RPTNO NOT NULL NUMBER LINENO NOT NULL NUMBER COMMENTS VARCHAR2(240) UPD_DATE DATE
The fact is that we store some header in RPTHEAD and store real data in RPTBODY, the question is that if I use below SQL to query all data for a 'PRODUCT_ID'.
SELECT t0.LINENO, t0.COMMENTS, t0.RPTNO, t0.UPD_DATE FROM RPTBODY t0 , RPTHEAD rpthead WHERE ( t0.RPTNO = rpthead.RPTNO AND t0.UPD_DATE>=to_date('1970/01/01 00:00:00','YYYY/MM/DD hh24:mi:ss') AND rpthead.PRODUCT_ID IN ('4647') )
I do not want to have 'ORDER by' clause since data set is too large, the sorting takes long time, is there any way to get the result rows in the order sorted by RPTNO? We have the index for RPTNO on RPTBODY.
I tried to make my Query as simple as possible but also it contains the problem:
SELECT A.Id,A.Attachment,A.CreateDateTime,A.No ,rownum as RowNumber FROM ( SELECT A.Id,A.Attachment,A.CreateDateTime,A.No FROM GOutgoingLetter A , ( SELECT B.Id, B.createdatetime as of0 FROM GOutgoingLetter B WHERE Exists [code]...
when I use Both Order By And RowNum in my Query, Two columns of final Select Are Null: NO & Attachment. whereas this Columns aren't empty.when I comment each one of "ORDER BY B.of0" or ",rownum as RowNumber " everything is correct!!
There are over 1500 records, but this query does not return any row. If i change rownum >= 100 to rownum <= 100 it returns first hundred records though... What is wrong here?
I'm on Oracle Database 10g Enterprise Edition Release 10.2.0.4.0
I am working on a project where have lots of view on a different schema. For performance reasons, we create tables on those views and index them.
The application that uses these tables requires a numeric primary key of a specific length, e.g. number(10). Not all tables have a natural key that matches this requirement, so I added a rownum to the query. I had hoped that casting the rownum to a number(10) would result in the same datatype once the table is created.
e.g. SQL> create or replace view rownum_to_number10_vw as 2 select cast(rownum as number(10)) objectid, dummy from dual;
View created
SQL> describe rownum_to_number10_vw; Name Type Nullable Default Comments -------- ---------------- -------- ------- -------- OBJECTID NUMBER(10) Y DUMMY VARCHAR2(1 BYTE) Y
SQL> perfect! Now create a table based on this view:
SQL> create table rownum_to_number10_tb as 2 select * from rownum_to_number10_vw;
Table created
SQL> describe rownum_to_number10_tb; Name Type Nullable Default Comments -------- ---------------- -------- ------- -------- OBJECTID NUMBER Y DUMMY VARCHAR2(1 BYTE) Y Oracle does not pick up on the number(10) cast!
How can I force Oracle to create a column with the same datetype as the underlying query?
ps:I know that the 10 in number(10) is more like a constraint than a datatype, but the application that uses this table will create an additional column if the datatype > 10. I want to prevent that from happening...
I have a requirement in SQL that I have to number each row. Hence I thought of using ROWNUM. But the sql query I'm using uses UNION operator. Hence I used like this
select a,b,rownum as 'field1' from table1 union select c,d,1 as 'field1' from table2
I have a result set with three columns as 'Product Category', 'Product' & 'QtySales' and 10 rows, sorted in the order Product Category, Product. This means, a product category will have one or more products under it.
Now i want to add a fourth column to my result set, which should display a incremental number sequence from starting from 1, 2, 3.. for each row. Also when the value of the Product Category (1st column) changes, this sequence should be restarted again from 1.
Using rownum in PL/SQL can significantly reduce performance and throughput of queries.
For example,
CODEselect * from (select ... from ... join ... on ... join ... on ... left join ... on ... where ... group by ...) where rownum < 500
takes much more time on a heavy loaded db than
CODEselect Y.* from ( select X.*, rank() over(order by ...) rnk from (select ... from ... join ... on ... join ... on ... left join ... on ... where ... group by ...) X) Y where rnk < 500
I suspect it's because Oracle optimizer goals all_rows and first_rows.
I am trying to do a simple query where I need to return the rows from a table and treat each rown according to some rules.The query works fine, and returns all the rows, usually I have 2 rows returned. WHen I add to the query where ROWNUM = 1, I get the first row returned, but when I use when ROWNUM =2 OR ROWNUM >1, I always get null rows retured, even if I have rows in the database. Here is my query:
SELECT on_time INTO on_time2 FROM work.work_unit WHERE work_code = 1 AND emp_no = :entry_blk.p_emp_no AND work_date = :entry_blk.p_work_date WHERE ROWNUM = 2; --RETURN NULL
I changed it to the following format, but still I get the same results, only I get data when I say when rownum = 1, i get back the first record in the query
SELECT on_time INTO on_time2 FROM (SELECT on_time FROM work.work_unit WHERE work_code = 1 AND emp_no = :entry_blk.p_emp_no AND work_date = :entry_blk.p_work_date) WHERE ROWNUM = 2;
I can't move forward in my form until I figure out why this is not returning records
title varchar2(100) y publisher varchar2(20) y categoryname varchar2(20) y rating varchar2(2) y
my query is, select ROWNUM AS "Rank",title,publisher from (select rating,title,publisher from bookshelf_test order by rating desc ) where ROWNUM <=3
returns result ,
1 1 MY LEDGER KOCH PRESS 2 2 TO KILL A MOCKINGBIRD HARPERCOLLINS 3 3 THE MISMEASURE OF MAN W.W. NORTON
But inner query (select rating,title,publisher from bookshelf_test order by rating desc ) returns,
1 5 WONDERFUL LIFE W.W.NORTON 2 5 THE MISMEASURE OF MAN W.W. NORTON 3 5 TO KILL A MOCKINGBIRD HARPERCOLLINS 4 5 MY LEDGER KOCH PRESS 5 4 TRUMAN SIMON SCHUSTER 6 4 GOSPEL PICADOR 7 4 HARRY POTTER AND THE GOBLET OF FIRE SCHOLASTIC 8 4 INNUMERACY VINTAGE BOOKS 9 4 JOHN ADAMS SIMON SCHUSTER 10 4 JOURNALS OF LEWIS AND CLARK MARINER 11 4 LETTERS AND PAPERS FROM PRISON SCRIBNER 12 4 PREACHING TO HEAD AND HEART ABINGDON PRESS 13 4 THE SHIPPING NEWS SIMON SCHUSTER 14 4 THE GOOD BOOK BARD 15 4 THE DISCOVERERS RANDOM HOUSE 16 3 THE COST OF DISCIPLESHIP TOUCHSTONE 17 3 SHOELESS JOE MARINER 18 3 KIERKEGAARD ANTHOLOGY PRINCETON UNIV PR 19 3 EMMA WHO SAVED MY LIFE ST MARTIN'S PRESS 20 3 EITHER/OR PENGUIN 21 3 CHARLOTTE'S WEB HARPERTROPHY 22 3 BOX SOCIALS MARINER 23 3 ANNE OF GREEN GABLES GRAMMERCY 24 3 WEST WITH THE NIGHT NORTH POINT PRESS 25 3 UNDER THE EYE OF THE CLOCK ARCADE PUB 26 3 TRUMPET OF THE SWAN HARPERCOLLINS 27 2 COMPLETE POEMS OF JOHN KEATS VIKING 28 1 POLAR EXPRESS HOUGHTON MIFFLIN 29 1 GOOD DOG, CARL LITTLE SIMON 30 1 MIDNIGHT MAGIC SCHOLASTIC 31 1 RUNAWAY BUNNY HARPERFESTIVAL
why final queries top 3 rows r different than inner query ?
how to select 1st record from duplicate vales in a table.
If we created one table with out primary key column In form in search block have uwi value and top_depth value when i enter uwi and top_depth value then when i click search button then it will display all values in master block.
but here duplicate values r there.
SQL> select rownum,uwi,top_depth,base_depth,test_start_date from well_pre_header;
