I have a table with about 8000 rows and 15 columns. After I have inserted the data I saw that my data was wrong after a number of records (let's say 1000) some column values belong to the previous record some thing like this:
A B C (A+B)
==================================
1 1 2
2 2 4
3 3 6
4 4 8
5 5
6 6 10
7 7 12
8 8 14
9 9 16
Now I have to either move some column values a record back or forward and I don't actually have much option testing it I'm afraid I may overwrite some data and ruin the whole table
I should do something like this but for about 7000 records:
update table1
set B = (select B from table1 where id = 1000)
where id = 999
Any ideas?
If you know the ids are sequential with no gaps, you can use a join to look up the value you want:
update t1
set c = tt1.c
from table1 t1 join
table1 t2
on t1.id = t2.id - 1
where t1.id > 1000;
If you cannot trust the ids, you can create the appropriate sequential number without gaps using row_number():
with toupdate as (
select t.*, row_number() over (order by id) as seqnum
from table1
)
update t1
set c = tt1.c
from toupdate t1 join
toupdate t2
on t1.seqnum = t2.seqnum - 1
where t1.id > 1000;
Create another table with the same fields as the table in question. Insert the bad records. Fix the data in the new table. Update the real table from the new one.
First, you should always test your statements before making definate changes to your data. You could start a transaction and only commit when certain it went well or make a copy of your table (select * into x from y) and test on that.
To answer your question, try something like this;
WITH dataToUpdate AS(
SELECT RowNr ,
DATA,
DataFromPreviousRow = FIRST_VALUE(data) OVER (ORDER BY RowNr ROWS 1 PRECEDING)
FROM dbo.test
)
UPDATE dataToUpdate
SET data = dataToUpdate.DataFromPreviousRow;
Related
I have a log table which logs a start row, and a finish row for a particular event.
Each event should have a start row, and if everything goes ok it should have an end row.
But if something goes wrong then the end row may not be created.
I want to SELECT everything in the table that has a start row but not an associated end row.
For example, consider the table like this:
id event_id event_status
1 123 1
2 123 2
3 234 1
4 234 2
5 456 1
6 678 1
7 678 2
Notice that the id column 5 has a start row but no end row. Start is an event_status of 1, end is an event_status of 2.
How can i pull back all the event_ids which have a start row but not an end row>?
This is for mssql.
You could use a not exists subquery to demand that no other row exists that ends the event:
select *
from YourTable t1
where status = 1
and not exists
(
select *
from YourTable t2
where t2.event_id = t1.event_id
and t2.status = 2
)
You can try with left self join as below:
select y1.event_id from #yourevents y1 left join #yourevents y2
on y1.event_id = y2.event_id
and y1.event_status = 1
and y2.event_status = 2
where y2.event_id is null
and y1.event_status = 1
In this particular case you could use one of 3 solutions:
Solution 1. The classic
Check if there is no end status
SELECT *
FROM myTable t1
WHERE NOT EXISTS (
SELECT *
FROM myTable t2
WHERE t1.event_id = t2.event_id AND t2.status=2
)
Solution 2. Make it pretty. Don't do subqueries with so many parentheses
The same check, but in a more concise and pretty manner
SELECT t1.*
FROM myTable t1
LEFT JOIN myTable t2 ON t1.event_id = t2.event_id AND t2.status=2
-- Doesn't exist
WHERE t2.event_id IS NULL
Solution 3. Look for the last status for each event
More flexibility in case the status logic becomes more complicated
WITH last_status AS (
SELECT
id,
event_id,
status,
-- The ROWS BETWEEN ..yadda yadda ... FOLLOWING might be unnecessary. Try, check.
last_value(status) OVER (PARTITION BY event_id ORDER BY status ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS last_status
FROM myTable
)
SELECT
id,
event_id,
status
FROM last_events
WHERE last_status<>2
There are more, with min/max queries and others. Pick what best suits your need for cleanliness, readability and versatility.
Here is an example of the tables I am joining together (note: the tables have the exact same schema but are in different databases, I am trying to combine them):
Database 1 Table
UniqID UniqID2 Number
100 150 1
100 151 2
Database 2 Table
UniqID UniqID2 Number
100 152 2
100 153 3
I am trying to merge Table2 into Table1 and I'm joining on Table1.UniqID = Table2.UniqID. I don't want any overlapping values in the Number column, this is what I want the result to look like:
Table 1
UniqID UniqID2 Number
100 150 1
100 151 2
100 152 3
100 153 4
This is the query I have so far, but it only updates the row in Table 2 where the Number = 2 and doesn't increment the Number = 3 row. How can I adjust my query to do so?
UPDATE db2
Set db2.Number = db2.Number +
(SELECT MAX(Number) FROM [Database 1]..db1 WHERE UniqID = db2.UniqID)
FROM [Database 2]..table db2
INNER JOIN [Database 1]..Table db1
ON db1.UniqID = db2.UniqID
AND db1.Number = db2.Number
And this is what my Database 2 Table results look like right now:
Database 2 Table
UniqID UniqID2 Number
100 152 3
100 153 3
Basically, the only difference is that I want the Number = 3 to be Number = 4 in the second column.
I think you want a union all query and insert:
insert into table1(UniqID, UniqID2, Number)
select t2.UniqID, t2.UniqID2,
(x.maxn + row_number() over (order by (select null) ))
from table2 t2 cross join
(select max(number) as maxn from table1) x;
A different appraoch could be
UPDATE t2
SET t2.Number = t1.T1Number + 1
FROM table2 t2
INNER JOIN (SELECT uniqid, uniqid2, number as T1Number from Table1
union
SELECT uniqid, uniqid2, number as T1Number from Table2
) t1
ON t1.uniqid = t2.uniqid and t1.UniqID2 = t2.UniqID2-1
one more approach which works in SQL 2012..
Demo here
;With cte
as
(select *
from
#t
union all
select *
from #t1
)
select uniqid,uniqid2,
case when lag(number) over (order by uniqid,uniqid2) is null then number
when lead(number) over (order by uniqid,uniqid2) is null
then number+1 else lead(number) over (order by uniqid,uniqid2) end as nextnumber
from cte
Suppose:
MyTable
--
Amount
1
2
3
4
5
MyTable only has one column, Amount, with 5 rows. They are not necessarily in increasing order.
How can I create a function, which takes a #SUM INT, and returns the TOP N rows that sum to this amount?
So for input 6, I want
Amount
1
2
3
Since 1 + 2 + 3 = 6. 2 + 4 / 1 + 5 won't work since I want TOP N ROWS
For 7/8/9/10, I want
Amount
1
2
3
4
I'm using MS SQL Server 2008 R2, if this matters.
Saying "top N rows" is indeed ambiguous when it comes to relational databases.
I assume that you want to order by "amount" ascending.
I would add a second column (to a table or view) like "sum_up_to_here", and create something like that:
create view mytable_view as
select
mt1.amount,
sum(mt2.amount) as sum_up_to_here
from
mytable mt1
left join mytable mt2 on (mt2.amount < mt1.amount)
group by mt1.amount
or:
create view mytable_view as
select
mt1.amount,
(select sum(amount) from mytable where amount < mt1.amount)
from mytable mt1
and then I would select the final rows:
select amount from mytable_view where sum_up_to_here < (some value)
If you don't bother about performance you may of course run it in one query:
select amount from
(
select
mt1.amount,
sum(mt2.amount) as sum_up_to_here
from
mytable mt1
left join mytable mt2 on (mt2.amount < mt1.amount)
group by mt1.amount
) t where sum_up_to_here < 20
One approach:
select t1.amount
from MyTable t1
left join MyTable t2 on t1.amount > t2.amount
group by t1.amount
having coalesce(sum(t2.amount),0) < 7
SQLFiddle here.
In Sql Server you can use CDEs to make it pretty simple to read.
Here is a CDE I did to sum up totals used in sequence. The CDE is similar to the joins above, and holds the total up to any given index. Outside of the CDE I join it back to the original table so I can select it along with other fields.
;with summrp as (
select m1.idx, sum(m2.QtyReq) as sumUsed
from #mrpe m1
join #mrpe m2 on m2.idx <= m1.idx
group by m1.idx
)
select RefNum, RefLineSuf, QtyReq, ProjectedDate, sumUsed from #mrpe m
join summrp on summrp.idx=m.idx
In SQL Server 2012 you can use this shortcut to get a result like Grzegorz's.
SELECT amount
FROM (
SELECT * ,
SUM(amount) OVER (ORDER BY amount ASC) AS total
from demo
) T
WHERE total <= 6
A fiddle in the hand... http://sqlfiddle.com/#!6/b8506/6
Consider the following dataset:
id dataid data
1 3095 5
1 3096 9
1 3097 8
2 3095 4
2 3096 9
2 3097 15
Now, in this, the column someid identifies to certain data, so if I see 3095, I know what data the data column represents (name, address, etc.). I need to do a check so that for the group of ids (i.e. 1 and 2) dataid=3095 then data=5 AND dataid=3096 then data=9, and if this is true, the id group will be selected and operations will be done on it.
Edit: Now I use the following SQL query to do the above:
SELECT *
FROM table s0
JOIN table s1 USING (dataid)
JOIN table s2 USING (dataid)
WHERE s1.dataid=359 AND s1.data=5
AND s2.dataid=360 AND s2.data=6;
But how can I get the output from rows to columns. The property values I need are still as key:pair values in rows and I would like them as columns.
So the output for the above would be:
id 3095 3096 3097
1 5 9 8
whereas currently it is returning from the above query:
id dataid data dataid_1 data_1 dataid_2 data_2
1 3095 5 Unnecessary stuff because of JOIN
1 3096 9
1 3097 8
Thanks and sorry if this is confusing.
SELECT id
FROM (SELECT DISTINCT id
FROM table) as ids
WHERE EXISTS (SELECT '1'
FROM table t2
WHERE t2.id = ids.id AND dataid = 3095 AND data = 5)
AND EXISTS (SELECT '1'
FROM table t2
WHERE t2.id = ids.id AND dataid = 3096 AND data = 9)
Also, if you're querying additional tables besides the given one (one with id as a unique key, preferrably), consider including that, to remove the need to use DISTINCT
I have result of two queries like:
Result of query 1
ID Value
1 4
2 0
3 6
4 9
Result of query 2
ID Value
1 6
2 4
3 0
4 1
I want to add values column "Value" and show final result:
Result of Both queries
ID Value
1 10
2 4
3 6
4 10
plz guide me...
select id, sum(value) as value
from (
select id, value from query1
uninon all
select id, value from query2
) x
group by id
Try using a JOIN:
SELECT
T1.ID,
T1.Value + T2.Value AS Value
FROM (...query1...) AS T1
JOIN (...query2...) AS T2
ON T1.Id = T2.Id
You may also need to consider what should happen if there is an Id present in one result but not in the other. The current query will omit it from the results. You may want to investigate OUTER JOIN as an alternative.
A not particularly nice but fairly easy to comprehend way would be:
SELECT ID,SUM(Value) FROM
(
(SELECT IDColumn AS ID,ValueColumn AS Value FROM TableA) t1
OUTER JOIN
(SELECT IDColumn AS ID,ValueColumn AS Value FROM TableB) t2
) a GROUP BY a.ID
It has the benefits of
a) I don't know your actual table structure so you should be able to work out how to get the two 'SELECT's working from your original queries
b) If ID doesn't appear in either table, that's fine