I’m joining dim table & fact table with start date. Can I use start date from dim table instead fact? If so why we need to use fact table start date? Below is the example:
Select count(*)
from dim_table d
Inner join fact_table f
On d.bizkeys = f.bizkeys
Where currentind =‘1’
And d.startdate = (select max(startdate) from dim_table)
After giving startdate condition I’m getting 1.8 million records, if I give
f.startdate = (select max(startdate) from fact_table)
I got 100 million records.
Can anyone Please clarify my doubt? Why I’m seeing this huge variation?
If you're just trying to get a list of all possible dates from the dimension (say, for a dropdown in your reporting tool that would let the user pick a date), then there's probably no reason that you would join to the fact table—unless you only want to include dates for which there's a corresponding fact record.
Without some sample data (or at least a little more information about the substance of the fact and dimension tables), I'm not sure I can give a better answer than that.
Related
Cant seem to wrap my head round this problem.
I have two tables one which has the following sample values:
Second table had the following values:
What i am trying to achieve is like the following:
So you can see the first table has the modules, what year and what term.
Based on these there is a start week and and end week.
The lookup table for the start and the finish unfortunatley is in a week basis and i need the begin week to match the second tables weekNo based on the season i guess and taking the start date being Sdate from that table to match what i am looking for and then the same applies to the end date.
Match the season and the endweek with the second tables WeekNo and Edate and only bring that date in.
Hope i made a bit of sense but i am hoping the third image shows what i am look for.
I've tried CTE, Group by, Partition by, order by, min, max and got nowhere :(
Dont really want to hard code anything, so was hoping you wonderful peps can help me out !!
Many thanks in advance :)
I suspect you are trying to achieve this by using one a single join between the tables - whereas what you actually need is two separate joins:
SELECT table1.module as mod_code,
table1.season as psl_code,
table2.Sdate as ypd_sdate,
table3.Edate as ypd_edate
FROM t1 as table1
JOIN t2 as table2 ON table2.yr = table1.year AND table2.season = table1.season AND table2.weekNo = table1.BeginWeek
JOIN t2 as table3 ON table3.yr = table1.year AND table3.season = table1.season AND table3.weekNo = table1.EndWeek
I need to create an interactive tool in SSRS or Access where users enter definitions of promotions, then system delivers sales data relevant to those criteria.
User will choose which promotion to report and system should use associated promo definitions to deliver results.
I tried using a prompt to select promotion, then inserting the prompted value in a subquery in Access, but it doesn't like my syntax. It looked like:
SELECT R.NumberPresented
FROM dbo_MKT_PromoRecapMetric R
WHERE R.DonationDate =
(Select P.5007Start
FROM [Promo Definitions] P
WHERE P.PromoName = [Forms]![Promo.Select]![Promo]
AND R.LocationCode = '5007')
I've been working on this for a LONG time, and any help would be much appreciated...
UPDATE: Thanks for the table join solution. I should have mentioned in my post that the date criteria is simplified. I actually will need to pick up a start and end date for the promotion to drive the date range for the query. I don't think I'd be able to do that with a join.
I think I'm looking for an equivalent of an Excel lookup in sql.
Thanks.
Instead of using a subquery for your where statement, try joining your tables instead.
SELECT R.NumberPresented
FROM dbo_MKT_PromoRecapMetric AS R
INNER JOIN [Promo Definitions] AS P
ON P.[5007Start] = R.DonationDate
WHERE (((P.PromoName)=[forms]![Promo.Select]![Promo])
AND ((R.LocationCode)="5007"));
-- Holds last 30 valdates
create table #valdates(
date int
)
insert into #valdates
select distinct top (30) valuation_date
from tbsm.tbl_key_rates_summary
where valuation_date <= 20150529
order by valuation_date desc
select
sum(fv_change), sc_group, valuation_date
from
(select *
from tbsm.tbl_security_scorecards_summary
where valuation_date in (select date from #valdates)) as fact
join
(select *
from tbsm.tbl_security_classification
where sc_book = 'UC' ) as dim on fact.classification_id = dim.classification_id
group by
valuation_date, sc_group
drop table #valdates
This query takes around 40 seconds to return because the fact table has almost 13 million rows.. Can I do anything about this?
Based on the fact that there's no proper index that supports the fetch, that's probably the easiest (or only) option to really improve the performance. Most likely index like this would improve the situation a lot:
create index idx_security_scorecards_summary_1 on
tbl_security_scorecards_summary (valuation_date, classification_id)
include (fv_change)
Everything depends of course on how good the selectivity of the valuation_date and classification_id fields are (=how big portion of the table needs to be fetched) and might work better with the fields in opposite order. The field fv_change is in the include section so that it's included in the index structure so there's no need to fetch it from the base table.
Include fields help if the SQL has to fetch a lot of rows from the table. If the amount of rows that this touches is small, then it might not help at all. Like always in indexing, this of course slows down the inserts / updates, and is optimized for this case only and you should of course look at the bigger picture too.
The select is written in a little bit strange way, not sure if that makes any difference, but you could also try the normal way to do this:
select
sum(fact.c), dim.sc_group, fact.valuation_date
from
tbsm.tbl_security_scorecards_summary fact
join tbsm.tbl_security_classification dim
on fact.classification_id = dim.classification_id
where
fact.valuation_date in (select date from #valdates) and
dim.sc_book = 'UC'
group by
fact.valuation_date,
dim.sc_group
Looking at "statistics io" output should give you a good idea which table is causing the slowness, and looking at query plan to see if there's any strange operators might help to understand the situation better.
I'm new to the working world an am fresh out of varsity. i started working an am creating a few reports via SQL reporting services as part of my training.
Here is quite a challenge that I am stuck at. Please help me finish this query. Here is how it goes!
There are several employees in the employee_table that each have unique identifier known as the emp_id
There is a time_sheet table that consists of several activities AND THE HOURS FOR EACH ONE for the employees and references them via emp_id. Each activity has a TIMESHEET_DATE that corresponds to the day all the activities were submitted(once a month). There are several activities with the same date because all those activities were submitted on the same day.
And there is a leave table that references the employees via emp_id. In the leave table, there is a column for the amount of days they took off and the starting day (Leave_FROM) of the leave.
I must create a parameter where the user inputs the month (easy peasy)...
Now in the report, column 1 must have their name (easy), column 2 must have their totals hours for the specified month (HOURS) and column 3 must show how many days they took leave for that month specified.
It can be tricky, not everybody has a entry in the leavetable, but everybody has got activities in the Time_Sheet table.
Here is what I have gotten so far from a query, but its not really helping me.
Unfortunately, I cannot upload pictures, so here is a link
http://imageshack.com/a/img822/8611/5czv.jpg
Oh yea, my flavor of SQL is SQL Server
You have a few different things you need to attack here.
First is getting information from the employee_table, regardless of what is in the other two tables. To do this, I would left join on both of the tables.
Your second battle is, now since you have multiple rows in your time_sheet table, you are going to get a record for every time_sheet record. That is not what you want. You can fix this by using a SUM Aggregate and a GROUP BY clause.
Next is the issue that you are going to have when nothing exists in leave table and it is returning NULL. If you add an ISNULL(value,0) around your leave table field, it will return 0 when no records exist on that table (for that employee).
Here is what your query should look like (not exactly sure on table/column naming):
I changed the query to use temp tables, so totals are stored separately. Since the temp tables will hold 0 for employees that don't have time/leave, you can do an inner join on your final query. Check this out for more information on temp tables.
SELECT e.emp_id, ISNULL(SUM(ts.Hours),0)[Time]
INTO #TotalTime
FROM employee e
LEFT JOIN time_sheet ts ON e.emp_id = ts.emp_id
GROUP BY e.emp_id
SELECT e.emp_id, ISNULL(SUM(l.days),0) [LeaveTime]
INTO #TotalLeave
FROM employee e
LEFT JOIN leaveTable l ON e.emp_id=l.emp_id
GROUP BY e.emp_id
SELECT e.Emp_Id,Time,LeaveTime FROM Employee e
INNER JOIN #TotalTime t ON e.Emp_Id=t.Emp_Id
INNER JOIN #TotalLeave l ON e.Emp_Id=l.Emp_Id
DROP TABLE #TotalLeave,#TotalTime
Here is the SQL Fiddle
Left join the leave table, if nobody took leave you won't get any results.
*EDIT** Thanks for all the input, and sorry for late reply. I have been away during the weekend without access to internet. I realized from the answers that I needed to provide more information, so people could understand the problem more throughly so here it comes:
I am migrating an old database design to a new design. The old one is a mess and very confusing ( I haven't been involved in the old design ). I've attached a picture of the relevent part of the old design below:
The table called Item will exist in the new design as well, and it got all columns that I need in the new design as well except one and it is here my problem begin. I need the column which I named 'neededProp' to be associated( with associated I mean like a column in the new Item table in the new design) with each new migrated row from Item.
So for a particular eid in table Environment there can be n entries in table Item. The "corresponding" set exists in table Room. The only way to know which rows that are associated in Item and Room are with the help of the columns "itemId" and "objectId" in the respective table. So for example for a particular eid there might be 100 entries in Item and Room and their "itemId" and "objectId" can be values from 1 to 100, so that column is only unique for a particular eid ( or baseSeq which it is called in table BaseFile).
Basically you can say that the tables Environment and BaseFile reminds of each other and the tables Item and Room reminds of each other. The difference is that some tables lack some columns and other may have some extra. I have no idea why it is designed like this from the beginning.
My question is if someone can help me with creating a query so that I can be able to find out the proper "neededProp" for each row in the Item-table so I can get that data into the new design?
*OLD-PART**This might be a trivial question but I can't get it to work as I want. I want to join a few tables as in the sql-statement below. If I start like this and run this query
select * from Environment e
join items ei on e.eid = ei.eid
I get like 400000 rows which is what I want. However if I add one more line so it looks like this:
select * from Environment e
join items ei on e.eid= ei.eid
left join Room r on e.roomnr = r.roomobjectnr
I get an insane amount of rows so there must be some multiplication going on. I want to get the same amount of rows ( like 400000 in this case ) even after joining the third table. Is that possible somehow? Maybe like creating a temporary view with the first 2 rows.
I am using MSSQL server.
So without knowing what data you have in your second query it's very difficult to say exactly how to write this out, and you're likely having a problem where there's an additional column that you are joining to in Rooms that perhaps you have forgotten such as something indicating a facility or hallway perhaps where you have multiple 'Room 1' entries as an example.
However, to answer your question regarding another way to write this out without using a temp table I've crufted up the below as an example of using a common table expression which will only return one record per source row.
;WITH cte_EnvironmentItems AS (
SELECT *
FROM Environment E
INNER JOIN Items I ON I.eid = E.eid
), cte_RankedRoom AS (
SELECT *
,ROW_NUMBER() OVER (ORDER BY R.UpdateDate DESC) [RN]
FROM Room R
)
SELECT *
FROM cte_EnvironmentItems E
LEFT JOIN cte_RankedRoom R ON E.roomnr = R.roomobjectnr
AND R.RN = 1
btw,do you want column from room table.if no then
select * from Environment e
join items ei on e.eid= ei.eid
where e.roomnr in (select r.roomobjectnr from Room r )
else
select * from Environment e
join items ei on e.eid= ei.eid
left join (select distinct roomobjectnr from Room) r on e.roomnr = r.roomobjectnr