Update Order column with number increasing (depend on ID column) - sql-server-2008

I'm using the SQL Server 2008.
Now I have the scenario as description below:
1 table with 3 columns: ID, Name, Order.
They has 8 records.
5 records have the same data: ID='1', Name='AAA'
3 records have the same data: ID='2', Name='BBB'
Now I want to update Order column with number increasing (start from 1) for each ID,Name:
No Name Order
1 AAA 1
1 AAA 2
1 AAA 3
1 AAA 4
1 AAA 5
2 BBB 1
2 BBB 2
2 BBB 3
How can I get this result without using Cursors?
I'm very appriciated for your help.
Thanks.

You can try the following. I use CTE to drive the update statement
WITH data AS
(
SELECT Order
, ROW_NUMBER() OVER (PARTITION BY ID, NAME
ORDER BY ID, NAME) AS Seq
FROM TableA
)
UPDATE data
SET Order = Seq
Substitute TableA with your table name

Related

MySQL count two rows as one

I need to count matches in a database.
Input:
id_to id_from
1 2
2 1
1 3
3 1
1 4
5 1
the 5th and 6th row has only one direction so doesn't count
Sample Output:
id_match
1
2
3
So, for 1 (implicit), 2 and 3 there is a reverse match but for 4 and 5 there aren't.
---- EDITED ----
Supposing the table name is "example" and I want to get all matches of id=1 then the SQL query will be:
SELECT count(*) FROM
(SELECT id_to FROM example WHERE id_from = 1) as t1,
(SELECT id_from FROM example WHERE id_to = 1) as t2
WHERE t1.id_to = t2.id_from
but maybe there is a better way to do it
You could try
SELECT DISTINCT id_from AS matched_id
FROM your_table AS data1
WHERE EXISTS (SELECT 1
FROM your_table AS data2
WHERE data1.id_from = data2.id_to
AND data1.id_to = data2.id_from)
I've created a demo here

Need MySql query that should return result by ordering values in particular field

Need MySql query that should return result by ordering values in particular field.
From below my result set should contain order like parent_id (1,4,6) should come first parent_id(2,3,7) come next and other should come last.
d data parent_id
----------------------
1 a1 1
2 abc 3
3 abcd 4
4 xyz 2
5 zxyy 6
2 abc 8
3 abcd 9
4 xyz 2
5 zxyy 15
Use a CASE expression in your ORDER BY clause:
SELECT d, data, parent_id
FROM yourTable
ORDER BY CASE WHEN parent_id IN (1, 4, 6) THEN 1
WHEN parent_id IN (2, 3, 7) THEN 2
ELSE 3 END,
parent_id
Follow the link below for a running demo:
SQLFiddle
Use below mentioned query
SELECT d, data, parent_id FROM table_name ORDER BY FIELD(parent_id,1,4,6,2,3,7);

Insert into a column using group by value of another column of the same table

id name count
------------
1 abc
2 xyz
3 xyz
4 xyz
The following query "select count(name) from temp group by name;" gives me:
count(name)
--------
1
3
I want this result to be updated to the column 'count'. To be precise I want my table to look like :
id name count
------------
1 abc 1
2 xyz 3
3 xyz 3
4 xyz 3
You can get those values with a COUNT / GROUP BY. You can do an UPDATE statement which joins your table with the sub query:-
UPDATE temp a
INNER JOIN
(
SELECT name, COUNT(*) AS name_count
FROM temp
GROUP BY name
) b
ON a.name = b.name
SET a.name_count = b.name_count;

delete all rows where column_id is xyz except one randomly selected

I have a record in table something like this
ID Name Value
1 abc 123
2 abc 152
3 cde 574
4 def 153
5 abc 777
How to delete row from the above column based on this algorithm,
We have same name for 3 rows (ID: 1,2,5). Delete all these rows except any one selected randomly. Same applied for other Names
Possible using sql or T-SQL?
;with d as (
select *, rowNum = row_number() over (partition by Name order by checksum(newid()))
from TableName
)
delete d
where rowNum > 1

MySQL fields from different rows to one string

I have table with data like this:
Id sort name
1 1 abc
1 2 kci
2 1 asd
2 2 eww
2 3 der
2 4 acu
3 1 awq
3 2 see
3 3 eee
is it possible to create query that will give me result
Id ConcName
1 abc,kci
2 asd,eww,der,acu
3 awq,see,eee
use GROUP_CONCAT()
SELECT ID,
GROUP_CONCAT(name ORDER BY sort ASC) ConcName
FROM tableName
GROUP BY ID
SQLFiddle Demo
GROUP_CONCAT()
SELECT `id`, GROUP_CONCAT(`name` ORDER BY `sort`)
FROM `myTable`
GROUP BY `Id`