I have a table with records:
DATE NAME AGE ADDRESS
01/13/2014 abc 27 us
01/29/2014 abc 27 ma <- duplicate
02/03/2014 abc 27 ny <- duplicate
02/03/2014 def 28 ca
I want to delete the record number 2 and 3 since they are duplicates for record 1 based on name and age. DATE column is a timestamp based from the record when it was added (sql date) and considered unique.
I found this sql but not sure if it will work and a bit concerned as the table has 2 million records and delting the wrong ones will be a bad idea:
SELECT A.DATE, A.NAME, A.AGE
FROM table A
WHERE EXISTS (SELECT B.DATE
FROM table B
WHERE B.NAME = A.NAME
AND B.AGE = A.AGE);
There are many instance of this records so if someone can help me write a sql to delete this records?
Query
DELETE FROM tbl t1
WHERE dt IN
(
SELECT t1.dt
FROM tbl t1
JOIN tbl t2 ON
(
t2.name = t1.name
AND t2.age=t1.age
AND t2.dt > t1.dt
)
);
Fiddle demo
delete from table
where (date, name, age) not in ( select max( date ), name, age from table group by name, age )
Before delete verify with
select * from table
where (date, name, age) not in ( select max( date ), name, age from table group by name, age )
ROW_NUMBER analytical function will helpful (supported by Oracle and Sqlserver).
The logic of assigning a unique ordered number for each row inside a partition, needs to be implemented carefully inside ORDER BY clause.
SELECT A_TABLE.*,
ROW_NUMBER ()
OVER (PARTITION BY NAME, AGE
ORDER BY DATE DESC)
seq_no
FROM A_TABLE;
Then you may use the result for delete operation:
Delete A_TABLE
where DATE,NAME,AGE IN
(
SELECT DATE,NAME,AGE FROM
(
SELECT A_TABLE.*,
ROW_NUMBER ()
OVER (PARTITION BY NAME, AGE
ORDER BY DATE DESC)
seq_no
FROM A_TABLE;
)
WHERE seq_no != 1
)
Related
I want to select without duplicate ids and keep row '5d' and not '5e' in select statement.
table
id | name
1 | a
2 | b
3 | c
5 | d
5 | e
I tried:
SELECT id, name
FROM table t
INNER JOIN (SELECT DISTINCT id FROM table) t2 ON t.id = t2.id
For the given example an aggregation using min() would work.
SELECT id,
min(name) name
FROM table
GROUP BY id;
You can also use ROW_NUMBER():
SELECT id, name
FROM (
SELECT id, name, ROW_NUMBER() OVER(PARTITION BY id ORDER BY name) rn
FROM mytable
) x
WHERE rn = 1
This will retain the record that has the smallest name (so '5d' will come before '5e'). With this technique, you can also use a sort criteria on another column that the one where duplicates exists (which an aggregate query with MIN() cannot do). Also, queries using window functions usually perform better than the equivalent aggregate query.
If you want to keep the row with the smallest name then you can use not exists:
select t.* from tablename t
where not exists (
select 1 from tablename
where id = t.id and name < t.name
)
I have a table containing status of a records. Something like this:
ID STATUS TIMESTAMP
1 I 01-01-2016
1 A 01-03-2016
1 P 01-04-2016
2 I 01-01-2016
2 P 01-02-2016
3 P 01-01-2016
I want to make a case where I take the newest version of each row, and for all P that has at some point been an I, they should be cased as a 'G' instead of P.
When I try to do something like
Select case when ID in (select ID from TABLE where ID = 'I') else ID END as status)
From TABLE
where ID in (select max(ID) from TABLE)
I get an error that this isn't possible using IN when casing.
So my question is, how do I do it then?
Want to end up with:
ID STATUS TIMESTAMP
1 G 01-04-2016
2 G 01-02-2016
3 P 01-01-2016
DBMS is IBM DB2
Have a derived table which returns each id with its newest timestamp. Join with that result:
select t1.ID, t1.STATUS, t1.TIMESTAMP
from tablename t1
join (select id, max(timestamp) as max_timestamp
from tablename
group by id) t2
ON t1.id = t2.id and t1.TIMESTAMP = t2.max_timestamp
Will return both rows in case of a tie (two rows with same newest timestamp.)
Note that ANSI SQL has TIMESTAMP as reserved word, so you may need to delimit it as "TIMESTAMP".
You can do this by using a common table expression find all IDs that have had a status of 'I', and then using an outer join with your table to determine which IDs have had a status of 'I' at some point.
To get the final result (with only the newest record) you can use the row_number() OLAP function and select only the "newest" record (this is shown in the ranked common table expression below:
with irecs (ID) as (
select distinct
ID
from
TABLE
where
status = 'I'
),
ranked as (
select
rownumber() over (partition by t.ID order by t.timestamp desc) as rn,
t.id,
case when i.id is null then t.status else 'G' end as status,
t.timestamp
from
TABLE t
left outer join irecs i
on t.id = i.id
)
select
id,
status,
timestamp
from
ranked
where
rn = 1;
other solution
with youtableranked as (
select f1.id,
case (select count(*) from yourtable f2 where f2.ID=f1.ID and f2."TIMESTAMP"<f1."TIMESTAMP" and f2.STATUS='I')>0 then 'G' else f1.STATUS end as STATUS,
rownumber() over(partition by f1.id order by f1.TIMESTAMP desc, rrn(f1) desc) rang,
f1."TIMESTAMP"
from yourtable f1
)
select * from youtableranked f0
where f0.rang=1
ANSI SQL has TIMESTAMP as reserved word, so you may need to delimit it as "TIMESTAMP"
try this
select distinct f1.id, f4.*
from yourtable f1
inner join lateral
(
select
case (select count(*) from yourtable f3 where f3.ID=f2.ID and f3."TIMESTAMP"<f2."TIMESTAMP" and f3.STATUS='I')>0 then 'G' else f2.STATUS end as STATUS,
f2."TIMESTAMP"
from yourtable f2 where f2.ID=f3.ID
order by f2."TIMESTAMP" desc, rrn(f2) desc
fetch first rows only
) f4 on 1=1
rrn(f2) order is for same last date
ANSI SQL has TIMESTAMP as reserved word, so you may need to delimit it as "TIMESTAMP"
Is there a way to union two tables, but keep the rows from the first table appearing first in the result set? However orderby column is not in select query
For example:
Table 1
name surname
-------------------
John Doe
Bob Marley
Ras Tafari
Table 2
name surname
------------------
Lucky Dube
Abby Arnold
Result
Expected Result:
name surname
-------------------
John Doe
Bob Marley
Ras Tafari
Lucky Dube
Abby Arnold
I am bringing Data by following query
SELECT name,surname FROM TABLE 1 ORDER BY ID
UNION
SELECT name,surname FROM TABLE 2
The above query is not keeping track of order by after union.
P.S - I dont want to show ID in my select query
I am getting ORDER BY Column by joining tables. Following is my real query
SELECT tbl_Event_Type_Sort_Orders.Appraisal_Event_Type_ID AS Appraisal_Event_Type_ID , ISNULL(tbl_Appraisal_Event_Types.Appraisal_Event_Type_Display_Name, 'UnCategorized') AS Appraisal_Event_Type_Display_Name
INTO #temptbl
FROM tbl_Event_Type_Sort_Orders
INNER JOIN tbl_Appraisal_Event_Types
ON tbl_Event_Type_Sort_Orders.Appraisal_Event_Type_ID = tbl_Appraisal_Event_Types.Appraisal_Event_Type_ID
WHERE 1=1
AND User_Name='abc'
ORDER BY tbl_Event_Type_Sort_Orders.Sort_Order
SELECT * FROM #temptbl
UNION
SELECT DISTINCT (tbl_Appraisal_Event_Types.Appraisal_Event_Type_ID) AS Appraisal_Event_Type_ID , ISNULL(tbl_Appraisal_Event_Types.Appraisal_Event_Type_Display_Name, 'UnCategorized') AS Appraisal_Event_Type_Display_Name
FROM tbl_Appraisal_Event_Types
INNER JOIN tbl_Appraisal_Events
ON tbl_Appraisal_Event_Types.Appraisal_Event_Type_ID = tbl_Appraisal_Events.Event_Type_ID
INNER JOIN tbl_Appraisals
ON tbl_Appraisal_Events.Appraisal_ID = tbl_Appraisal_Events.Appraisal_ID
WHERE 1=1
AND ((tbl_Appraisals.Assigned_To_Staff_User) = 'abc' OR (tbl_Appraisals.Assigned_To_Staff_User2) = 'abc' OR (tbl_Appraisals.Assigned_To_Staff_User3) = 'abc')
Put a UNION ALL in a derived table. To keep duplicate elimination, do select distinct and also add a NOT EXISTS to second select to avoid returning same person twice if found in both tables:
select name, surname
from
(
select distinct name, surname, 1 as tno
from table1
union all
select distinct name, surname, 2 as tno
from table2 t2
where not exists (select * from table1 t1
where t2.name = t1.name
and t2.surname = t1.surname)
) dt
order by tno, surname, name
You can use a column for the table and one for the ID to order by:
SELECT x.name, x.surname FROM (
SELECT ID, TableID = 1, name, surname
FROM table1
UNION ALL
SELECT ID = -1, TableID = 2, name, surname
FROM table2
) x
ORDER BY x.TableID, x.ID
You can write as below, if you are ok with duplicate data then please use UNION ALL it will be faster:
SELECT NAME, surname FROM (
SELECT ID,name,surname FROM TABLE 1
UNION
SELECT ID,name,surname FROM TABLE 2 ) t ORDER BY ID
this will order the first row sets first then by anything you need
(haven't tested the code)
;with cte_1
as
(SELECT ID,name,surname,1 as table_id FROM TABLE 1
UNION
SELECT ID,name,surname,2 as table_id FROM TABLE 2 )
SELECT name, surname
FROM cte_1
ORDER BY table_id,ID
simply use a UNION clause with out order by.
SELECT name,surname FROM TABLE 1
UNION
SELECT name,surname FROM TABLE 2
if you wanted to order first table use the below query.
;WITH cte_1
AS
(SELECT name,surname,ROW_NUMBER()OVER(ORDER BY Id)b FROM TABLE 1 )
SELECT name,surname
FROM cte_1
UNION
SELECT name,surname
FROM TABLE 2
In my table I need to know if each ID has one and only one ID_name. How can I write such query?
I tried:
select ID, count(distinct ID_name) as count_name
from table
group by ID
having count_name > 1
But it takes forever to run.
Any thoughts?
select ID
from YourTable
group by
ID
having count(distinct ID_name) > 1
or
select *
from YourTable yt1
where exists
(
select *
from YourTable yt2
where yt1.ID = yt2.ID
and yt1.ID_Name <> yt2.ID_Name
)
Now, most ID columns are defined as primary key and are unique. So in a regular database you'd expect both queries to return an empty set.
select tt.ID,max(tt.myRank)
from
(
select
ip.ID,ip.ID_name,
ROW_Number() over (partition by ip.ID,ip.ID_nameorder by ip.ID) as myRank
from YourTable ip
) tt
group by tt.ID
This gives you every ID with it's total number of ID_Name
If you want only those ID's which have more than one name associated just add a where clause
e.g.
select tt.ID,max(tt.myRank)
from
(
select
ip.ID,ip.ID_name,
ROW_NUMBER() over (partition by ip.ID,ip.ID_nameorder by ip.ID) as myRank
from YourTable ip
) tt
**where tt.myRank > 1**
group by tt.ID
I have a table with 10 columns.
I want to return all rows for which Col006 is distinct, but return all columns...
How can I do this?
if column 6 appears like this:
| Column 6 |
| item1 |
| item1 |
| item2 |
| item1 |
I want to return two rows, one of the records with item1 and the other with item2, along with all other columns.
In SQL Server 2005 and above:
;WITH q AS
(
SELECT *, ROW_NUMBER() OVER (PARTITION BY col6 ORDER BY id) rn
FROM mytable
)
SELECT *
FROM q
WHERE rn = 1
In SQL Server 2000, provided that you have a primary key column:
SELECT mt.*
FROM (
SELECT DISTINCT col6
FROM mytable
) mto
JOIN mytable mt
ON mt.id =
(
SELECT TOP 1 id
FROM mytable mti
WHERE mti.col6 = mto.col6
-- ORDER BY
-- id
-- Uncomment the lines above if the order matters
)
Update:
Check your database version and compatibility level:
SELECT ##VERSION
SELECT COMPATIBILITY_LEVEL
FROM sys.databases
WHERE name = DB_NAME()
The key word "DISTINCT" in SQL has the meaning of "unique value". When applied to a column in a query it will return as many rows from the result set as there are unique, different values for that column. As a consequence it creates a grouped result set, and values of other columns are random unless defined by other functions (such as max, min, average, etc.)
If you meant to say you want to return all rows for which Col006 has a specific value, then use the "where Col006 = value" clause.
If you meant to say you want to return all rows for which Col006 is different from all other values of Col006, then you still need to specify what that value is => see above.
If you want to say that the value of Col006 can only be evaluated once all rows have been retrieved, then use the "having Col006 = value" clause. This has the same effect as the "where" clause, but "where" gets applied when rows are retrieved from the raw tables, whereas "having" is applied once all other calculations have been made (i.e. aggregation functions have been run etc.) and just before the result set is returned to the user.
UPDATE:
After having seen your edit, I have to point out that if you use any of the other suggestions, you will end up with random values in all other 9 columns for the row that contains the value "item1" in Col006, due to the constraint further up in my post.
You can group on Col006 to get the distinct values, but then you have to decide what to do with the multiple records in each group.
You can use aggregates to pick a value from the records. Example:
select Col006, min(Col001), max(Col002)
from TheTable
group by Col006
order by Col006
If you want the values to come from a specific record in each group, you have to identify it somehow. Example of using Col002 to identify the record in each group:
select Col006, Col001, Col002
from TheTable t
inner join (
select Col006, min(Col002)
from TheTable
group by Col006
) x on t.Col006 = x.Col006 and t.Col002 = x.Col002
order by Col006
SELECT *
FROM (SELECT DISTINCT YourDistinctField FROM YourTable) AS A
CROSS APPLY
( SELECT TOP 1 * FROM YourTable B
WHERE B.YourDistinctField = A.YourDistinctField ) AS NewTableName
I tried the answers posted above with no luck... but this does the trick!
select * from yourTable where column6 in (select distinct column6 from yourTable);
SELECT *
FROM harvest
GROUP BY estimated_total;
You can use GROUP BY and MIN() to get more specific result.
Lets say that you have id as the primary_key.
And we want to get all the DISTINCT values for a column lets say estimated_total, And you also need one sample of complete row with each distinct value in SQL. Following query should do the trick.
SELECT *, min(id)
FROM harvest
GROUP BY estimated_total;
create table #temp
(C1 TINYINT,
C2 TINYINT,
C3 TINYINT,
C4 TINYINT,
C5 TINYINT,
C6 TINYINT)
INSERT INTO #temp
SELECT 1,1,1,1,1,6
UNION ALL SELECT 1,1,1,1,1,6
UNION ALL SELECT 3,1,1,1,1,3
UNION ALL SELECT 4,2,1,1,1,6
SELECT * FROM #temp
SELECT *
FROM(
SELECT ROW_NUMBER() OVER (PARTITION BY C6 Order by C1) ID,* FROM #temp
)T
WHERE ID = 1