We have DataTemp table which has the records in desc order.
select * from (
select 9,'a',3 union
select 8,'a',2 union
select 7,'b',3 union
select 6,'a',1 union
select 5,'b',2 union
select 4,'c',3 union
select 3,'c',2 union
select 2,'b',1 union
select 1,'c',1
) door (sno,id, N_th_Reocord)
sno - Auto Id.
id - code of the Doors*.
N_th_Record - for denoting the n the record.
At a time, only three* records per Door are need to store on this table. For example Door 'a' has new entry(means 4th record) then first of 'a' Door need to delete.
4th record:
select * from (
select 10,'a',4 union --- new entry
select 9,'a',3 union
select 8,'a',2 union
select 7,'b',3 union
select 6,'a',1 union -- need to delete
select 5,'b',2 union
select 4,'c',3 union
select 3,'c',2 union
select 2,'b',1 union
select 1,'c',1
) door (sno,id, N_th_Reocord)
I do following query. But I need easiest way for deleting the row. Because, we are try to reduce the time consumption of over all project.
delete from door where sno = (
select sno from (
select 10,'a',4 union
select 9,'a',3 union
select 8,'a',2 union
select 7,'b',3 union
select 6,'a',1 union
select 5,'b',2 union
select 4,'c',3 union
select 3,'c',2 union
select 2,'b',1 union
select 1,'c',1
) door (sno,id, N_th_Reocord)
where id = 'a'
order by sno desc -- For 'DataTemp' *order by* is no needed.
offset 3 rows fetch next 1 rows only
)
Note:
Three rows and three Door are given for example. Actually we work with 144 rows per 12 Doors.
Before this delete, we check lot of Business rules.
Version: SQL Server 2012
You could use ROW_NUMBER:
WITH cte AS (SELECT *,ROW_NUMBER() OVER(PARTITION BY id ORDER BY sno DESC) rn FROM t)
DELETE FROM cte WHERE rn > 3;
db<>fiddle demo
I need the count of this:
select distinct ID
from (
select ID from A
union all
select ID from B
union all
select ID from C
) ids
GROUP BY ID HAVING COUNT(*) > 1;
but I have no idea how to do it.
Use a subquery:
select count(*)
from (select ID
from (select ID from A
union all
select ID from B
union all
select ID from C
) ids
group by ID
having count(*) > 1
) i;
SELECT DISTINCT is almost never needed with GROUP BY and definitely not in this case.
You just want to find the id that appear 2 more times in the A,B,C table, the SQL is below:
select count(1) from (
select
id,
count(1)
from
(
select ID from A
union all
select ID from B
union all
select ID from C
)
group by id having(count(1)>1)
) tmp
As the title says, I'm trying to add an extra column to a table which autoincrements everytime a different string in another column changes.
I would like to do this in a query.
Example:
MyCol GroupID
Cable 1
Cable 1
Foo 2
Foo 2
Foo 2
Fuzz 3
Fizz 4
Tv 5
Tv 5
The GroupID column is what I want to accomplish.
We can be sure that MyCol's strings will be the same in each subgroup (Foo will always be Foo, etc).
Thanks in advance
If I understand correctly, you can use dense_rank():
select t.*, dense_rank() over (order by col1) as groupid
from t;
You could make a temporal table with the distinct value of the MyCol and get the groupId throught the RowNumber of the temp table, and join the rownumbered result with your table.
This is a raw example in oracle:
WITH data AS
(SELECT 'Cable' MyCol FROM dual
UNION ALL
SELECT 'Cable' FROM dual
UNION ALL
SELECT 'Foo' FROM dual
UNION ALL
SELECT 'Foo' FROM dual
UNION ALL
SELECT 'Foo' FROM dual
UNION ALL
SELECT 'Fuzz' FROM dual
UNION ALL
SELECT 'Fizz' FROM dual
UNION ALL
SELECT 'Tv' FROM dual
UNION ALL
SELECT 'Tv' FROM dual
),
tablename AS
(SELECT * FROM data
),
temp AS
( SELECT DISTINCT mycol FROM tablename
),
temp2 AS
( SELECT mycol, rownum AS groupid from temp
)
SELECT tablename.mycol, temp2.groupid FROM temp2 JOIN tablename ON temp2.mycol = tablename.mycol
You could also check for a way to implement the tabibitosan method knowing that your column condition is string.
I Have a query with Two Select Clause combines with UNION.I want to select only top first row. How can i do that Using Union ?
Select Fault,OccurredOn From ATMStatus Where Ticket=189703 // This Will retrieve single record as the primary key is applied
Union
Select Fault,OccurredOn From ATMStatusHistory Where Resolved=0 AND Ticket=189703 Order By OccurredOn Desc
select top 1 * from
(
Select Fault,OccurredOn
From ATMStatus
Where Ticket=189703
Union
Select Fault,OccurredOn
From ATMStatusHistory
Where Resolved=0 AND Ticket=189703
) x
Order By OccurredOn Desc
This returns 2 rows:
select 1 as id
union
select 2 as id
This returns 1 row:
select top 1 * from (
select 1 as id
union
select 2 as id
) as x
order by id
Can I create a table from a query formed using with clause?
Sure:
CREATE TABLE t
AS
WITH some_data AS (
SELECT 1 as some_value
FROM dual
UNION ALL
SELECT 2
FROM dual
)
SELECT *
FROM some_data
The CREATE TABLE table_name AS statement creates a table based on a select statement. The solution for a with clause will be :
CREATE TABLE t
AS
SELECT * FROM (
WITH some_data AS (
SELECT 1 as some_value
FROM dual
UNION ALL
SELECT 2
FROM dual
)
);
For multiple CTE (common table expressions; i.e. multiple WITH clause), I found the same syntax worked. i.e.
CREATE TABLE schema.table_name as
WITH table1 as (SELECT 1),
table2 as (SELECT 2)
select * from table2
will create the table_name in the schema from the select statement