Probably it has been asked before but I cannot find an answer.
Table Data has two columns:
Source Dest
1 2
1 2
2 1
3 1
I trying to come up with a MS Access 2003 SQL query that will return:
1 2
3 1
But all to no avail. Please help!
UPDATE: exactly, I'm trying to exclude 2,1 because 1,2 already included. I need only unique combinations where sequence doesn't matter.
For Ms Access you can try
SELECT DISTINCT
*
FROM Table1 tM
WHERE NOT EXISTS(SELECT 1 FROM Table1 t WHERE tM.Source = t.Dest AND tM.Dest = t.Source AND tm.Source > t.Source)
EDIT:
Example with table Data, which is the same...
SELECT DISTINCT
*
FROM Data tM
WHERE NOT EXISTS(SELECT 1 FROM Data t WHERE tM.Source = t.Dest AND tM.Dest = t.Source AND tm.Source > t.Source)
or (Nice and Access Formatted...)
SELECT DISTINCT *
FROM Data AS tM
WHERE (((Exists (SELECT 1 FROM Data t WHERE tM.Source = t.Dest AND tM.Dest = t.Source AND tm.Source > t.Source))=False));
your question is asked incorrectly. "unique combinations" are all of your records. but i think you mean one line per each Source. so it is:
SELECT *
FROM tab t1
WHERE t1.Dest IN
(
SELECT TOP 1 DISTINCT t2.Dest
FROM tab t2
WHERE t1.Source = t2.Source
)
SELECT t1.* FROM
(SELECT
LEAST(Source, Dest) AS min_val,
GREATEST(Source, Dest) AS max_val
FROM table_name) AS t1
GROUP BY t1.min_val, t1.max_val
Will return
1, 2
1, 3
in MySQL.
To eliminate duplicates, "select distinct" is easier than "group by":
select distinct source,dest from data;
EDIT: I see now that you're trying to get unique combinations (don't include both 1,2 and 2,1). You can do that like:
select distinct source,dest from data
minus
select dest,source from data where source < dest
The "minus" flips the order around and eliminates cases where you already have a match; the "where source < dest" keeps you from removing both (1,2) and (2,1)
Use this query :
SELECT distinct * from tabval ;
Related
Hell all,
i have a Logs tables that shows the workflow of a Task ID i want to display IDs that does not have a specific step.
The problem:
the problem i have with using the below query is that the TASK IDs is duplicated and it.
expected Result:
remove all Same duplicate Task Id if one of them contains the 'Cart' as STEPNAME
Query:
SELECT *
FROM MV.Tasks
Where WF_TASK_NAME = 'ExemptionTask'
and stepname not in ('Cart')
I think that you want not exists:
select t.*
from mv.tasks t
where
wf_task_name = 'ExemptionTask'
and not exists (
select 1
from mv.tasks t1
where t1.id = t.id and t1.wf_task_name = t.wf_task_name and t1.step_name = 'cart'
)
SELECT
*
FROM
mv.tasks
WHERE
wf_task_name = 'ExemptionTask'
AND id NOT IN (
SELECT DISTINCT
id
FROM
mv.tasks
WHERE
step_name = 'cart'
)
Following are the two tables in SQL Server: TABLE_A and TABLE_B
I need to get the output as follows:
Get IDs from TABLE_A where Exist = 0
We would get 100, 101 & 102
Now, among 100, 101 & 102, no other rows (in the same table) with the same ID value should have Exist = 1
Hence, 100 can't be selected as it has Exist = 1 in the 2nd row.
So, only 101 & 102 remain
With the remaining ID values (101 & 102), check against the ID column in TABLE_B where 'Exist' column value should not be equal to '1' in any of the rows
In TABLE_B, 4th row has Exist = 1 for 102. So, that can't be selected
We have only 101 now. This is required output and that should be selected.
Could you let me know how to write the simplest query to achieve this please? Let me know if the question needs to be improved.
You can use exists & not exists :
with t as (
select t1.*
from t1
where exists (select 1 from t1 t11 where t11.id = t1.id and t11.exists = 0) and
not exists (select 1 from t1 t11 where t11.id = t1.id and t11.exists = 1)
)
select t.*
from t
where not exists (select 1 from t2 where t.id = t2.id and t2.exists = 1);
Try:
SELECT
ID,
SUM(CAST(Exist AS int)) AS [Exists]
FROM
TABLE_A
GROUP BY ID
HAVING SUM(CAST(Exist AS bit)) = 0
will give you the answer to the first part. You can then JOIN this to a similar query for TABLE_B. That is a "simple" way to show how this works. You can write more complex queries as that from #Yogest Sharma
Like #Peter Smith mentioned, you can use the aggregate function SUM. Note that you would need a cast since you cannot use the aggregate function on a field that has a BIT datatype
;WITH CTE AS
(
SELECT ID, SUM(CAST(Exist AS INT)) AS AggExist FROM TABLE_A GROUP BY ID
UNION
SELECT ID, SUM(CAST(Exist AS INT)) As AggExist FROM TABLE_B GROUP BY ID
)
SELECT ID, SUM(AggExist) FROM CTE GROUP BY ID
HAVING SUM(AggExist) = 0
Here is the demo
I have this table
mt.id, mt.otherId, mt.name, mt.myChar, mt.type
1 10 stack U "question"
2 10 stack D
3 30 stack U "question"
4 10 stack U "whydownvotes"
And I want only
rows with id 2 and 3 returned (without using the id, otherid as parameter) and ensuring name and type are matching against parameters. And when there is a duplicate otherId = then return the row with min myChar value. So far I have this :
select mt.* from myTable mt
where (mt.myChar = 'U' AND (mt.name = 'stack' AND mt.type LIKE '%question%'))
or (mt.myChar = 'D' and mt.name = 'stack')
So where otherID is 10, I want the row with min char value 'D'. I am going to need a subquery or group using min(myChar) ... ?
How do i remove the first row from the sql fiddle (without using the id):
http://sqlfiddle.com/#!9/c579a/1
edit
Jeepers, whats with the downvotes, its clear question isn't it ? There is even a sql fiddle.
If this is SQL Server, then you can do it in two steps like this:
WITH filtered AS (
SELECT
mt.*,
minType = MIN(mt.type) OVER (PARTITION BY mt.otherId)
FROM
dbo.myTable AS mt
WHERE (mt.myChar = 'U' AND mt.name = 'stack' AND mt.type LIKE '%question%')
OR (mt.myChar = 'D' AND mt.name = 'stack')
)
SELECT
id,
otherId,
name,
myChar,
type
FROM
filtered
WHERE
type = minType
;
The filtered subquery is basically your current query but with an additional column that holds minimum type values per otherId. The main query filters the filtered set further based on the type = minType condition.
I am assuming you want is a groupwise maximum, one of the most commonly-asked SQL questions You can try as , This query should work on any DBMS. But If you are using the SQL SERVER then you can use the Row_Number() which is very easy to use.Here myTable is your table.
SELECT t0.*
FROM myTable AS t0
LEFT JOIN myTable AS t1 ON t0.otherId = t1.otherId AND t1.myChar < t0.myChar
WHERE t1.myChar IS NULL;
Here is sql fiddle
SQL Server 2008-12
I have table:
InteractionKey char(18)
dEventTime datetime
SeqNo int
cEventData1
There will be multiple entries per InteractionKey - dEventTime only goes out to the Seconds and SeqNo is incremented if two entries occur on the same second.
What I need to do is select the First and Second record BEFORE the record where
cEventData1 = 'Disconnect'
The final product will give me a count of occurrences grouped by cEventData1.
I am currently using a cursor (will update with cursor source momentarily) I would like to use a CTE - but I really struggle with understanding them...
Any ideas would be appreciated!
Update with Data Sample
INTERACTIONKEY dEventTime SeqNo cEventData1
100186322420130722 2013-07-22 11:50:49.000 1 EnterPassword
100186322420130722 2013-07-22 11:50:49.000 2 CheckPassword
100186322420130722 2013-07-22 11:50:49.000 3 Attendant Disconnect
The result of the query would ideally tell me - : NOTE The Action column here can be simply 'Attendant Disconnect' as Action
cEventData1 Action Count
CheckPassword Attendant Disconnect 1
Here is the query I ended up going with based upon the below answer
SELECT DISTINCT t1.InteractionKey,
DisconnectTime = t1.dEventTime,
PreviousEventTime = t2.dEventTime,
PreviousEvent = t2.cEventData1,
t2.SeqNo
FROM IVRHistory t1
OUTER APPLY
( SELECT TOP 1 t2.dEventTime, t2.SeqNo, t2.cEventData1
FROM IVRHistory t2
WHERE t1.InteractionKey = t2.InteractionKey
AND t1.dEventTime >= t2.dEventTime
AND t1.SeqNo > t2.SeqNo
AND t2.cEventData1 <> 'Attendant Disconnect'
ORDER BY t2.dEventTime DESC, t2.SeqNo DESC
) t2
WHERE t1.cEventData1 = 'Attendant Disconnect'
I would approach this using APPLY:
SELECT t1.InteractionKey,
DisconnectTime = t1.dEventTime,
PreviousEventTime = t2.dEventTime,
PreviousEvent = t2.cEventData1,
t2.SeqNo
FROM T t1
OUTER APPLY
( SELECT TOP 2 t2.dEventTime, t2.SeqNo, t2.cEventData1
FROM T t2
WHERE t1.InteractionKey = t2.InteractionKey
AND t1.dEventTime > t2.dEventTime
ORDER BY t2.dEventTime DESC
) t2
WHERE t1.cEventData1 = 'Disconnect';
This will give you the two records immediately preceeding the disconnect event. If you need more than two records if there are duplicate times you can use TOP 2 WITH TIES.
Without your sample input and output I am guessing a bit, but from what you have said your final aggregate would be:
SELECT t2.cEventData1,
Occurances = COUNT(*)
FROM T t1
OUTER APPLY
( SELECT TOP 2 t2.dEventTime, t2.SeqNo, t2.cEventData1
FROM T t2
WHERE t1.InteractionKey = t2.InteractionKey
AND t1.dEventTime > t2.dEventTime
ORDER BY t2.dEventTime DESC
) t2
WHERE t1.cEventData1 = 'Disconnect'
GROUP BY t2.cEventData1;
I have a sql query that I run against a sql server database eg.
SELECT * FROM MyTable WHERE Id = 2
This may return a number of records or may return none. If it returns none, I would like to alter my sql query to return a default record, is this possible and if so, how? If records are returned, the default record should not be returned. I cannot update the data so will need to alter the sql query for this.
Another way (you would get an empty initial rowset returned);
SELECT * FROM MyTable WHERE Id = 2
IF (##ROWCOUNT = 0)
SELECT ...
SELECT TOP 1 * FROM (
SELECT ID,1 as Flag FROM MyTable WHERE Id = 2
UNION ALL
SELECT 1,2
) qry
ORDER BY qry.Flag ASC
You can have a look to this post. It is similar to what you are asking
Return a value if no rows are found SQL
I hope that it can guide you to the correct path.
if not exists (SELECT top 1 * FROM mytable WHERE id = 2)
select * from mytable where id= 'whatever_the_default_id_is'
else
select * from mytable where id = 2
If you have to return whole rows of data (and not just a single column) and you have to create a single SQL query then do this:
Left join actual table to defaults single-row table
select
coalesce(a.col1, d.col1) as col1,
coalesce(a.col2, d.col2) as col2,
...
from (
-- your defaults record
select
default1 as col1,
default2 as col2,
...) as d
left join actual as a
on ((1 = 1) /* or any actual table "where" conditions */)
The query need to return the same number of fields, so you shouldn't do a SELECT * FROM but a SELECT value FROM if you want to return a default value.
With that in mind
SELECT value FROM MyTable WHERE Id = 2
UNION
SELECT CASE (SELECT count(*) FROM MyTable WHERE Id = 2)
WHEN 0 THEN 'defaultvalue'
END