how to convert an empty record to zero - sql

I am working on a Point-of-sale system, but I have been stranded lately. I have two tables from which I want to pick data, but some of the values I retrieve are NULLs, whereas I need them to be zeros. This happens when there is a row in one table ([dbo.ProdDetails]) without a corresponding row in the other table [dbo.Pro_Sales].
I am using this query:
SELECT a.ItemCODE,a.OpenStock,c.UnitsSold
FROM
(SELECT x.ItemCODE,x.OpenStock FROM dbo.ProdDetails x) a
LEFT OUTER JOIN
(SELECT x.ProductID,ISNULL(CONVERT(varchar(50),x.Quantity),'') UnitsSold
FROM dbo.Pro_Sales x
GROUP BY x.ProductID,x.Quantity
) c
ON a.ItemCODE=c.ProductID
WHERE a.ItemCODE ='0005'
The result am getting is
itemCode OpenStock UnitsSold
0005 6 NULL

Use ISNULL(columnName, alt.Value) as columnName:
SELECT a.ItemCODE,a.OpenStock,ISNULL(c.UnitsSold,0) as UnitsSold
FROM
(SELECT x.ItemCODE,x.OpenStock FROM dbo.ProdDetails x) a
LEFT OUTER JOIN
(SELECT x.ProductID,ISNULL(CONVERT(varchar(50),x.Quantity),'') UnitsSold
FROM dbo.Pro_Sales x
GROUP BY x.ProductID,x.Quantity
) c
ON a.ItemCODE=c.ProductID
WHERE a.ItemCODE ='0005'

This is what the COALESCE() function is for:
SELECT a.ItemCODE, a.OpenStock, COALESCE(c.UnitsSold, 0) AS UnitsSold
FROM
(SELECT x.ItemCODE,x.OpenStock FROM dbo.ProdDetails x) a
LEFT OUTER JOIN
(SELECT x.ProductID,ISNULL(CONVERT(varchar(50),x.Quantity),'') UnitsSold
FROM dbo.Pro_Sales x
GROUP BY x.ProductID,x.Quantity
) c
ON a.ItemCODE=c.ProductID
WHERE a.ItemCODE ='0005'

Related

Sql query tuning/optimization

For large amounts of data, it is taking a lot of time to execute.
Please help tune this query.
select *
from
(select cs.sch, cs.cls, cs.std, d.date, d.count
from
(select c.sch, c.cls, s.std
from
(select distinct sch, cls from Data) c --List of school/classes
cross join
(select distinct std from Data) s --list of std
) cs --every possible combination of school/classes and std
left outer join
Data D on D.sch = cs.sch and D.cls = cs.cls and D.std = cs.std --try and join to the original data
group by
c.sch, c.cls, s.std, d.date, d.count)
order by
cs.sch, cs.cls,
case
when (cs.std= 'Ax')
then 1
when (cs.std= 'Bo')
then 2
when (cs.std= 'Ct')
then 3
else null
end
Thanks in advance
Magickk
First, the query is generating a lot of rows (presumably) and so it is going to take time.
From what I can tell, the outer aggregation is not necessary. At the very least, you have no aggregation functions which is suspicious.
select c.sch, c.cls, s.std, d.date, d.count
from (Select distinct sch, cls from Data
) c cross join -- list of school/classes
(select distinct std from Data
) s left join -- list of std
Data d
on d.sch = cs.sch and d.cls = cs.cls and d.std = cs.std
order by cs.sch, cs.cls,
(case cs.std when 'Ax' then 1 when 'Bo' then 2 when 'Ct' else 3 end)
There is nothing you can do about the outer order by. For the select distinct subqueries, you can create indexes on data(sch, cls, std) (the third column is for the join) and data(std).
DISTINCT is slowing down performance on big tables. Instead, a replacement for DISTINCT could be GROUP BY (wich in some scenarios is more rapid)
select *
from
(select cs.sch, cs.cls, cs.std, d.date, d.count
from
(select c.sch, c.cls, s.std
from
(select sch, cls from Data
group by sch, cls) c
cross join
(select std from Data
group by std) s) cs --every possible combination of school/classes and std
left outer join
Data D on D.sch = cs.sch and D.cls = cs.cls and D.std = cs.std --try and join to the original data
group by
c.sch, c.cls, s.std, d.date, d.count)
order by
cs.sch, cs.cls,
case
when (cs.std= 'Ax')
then 1
when (cs.std= 'Bo')
then 2
when (cs.std= 'Ct')

Sql code for distinct fields

I was wondering if anyone can help me with this query.
I have two tables that I join together (DDS2ENVR.QBO AND KCA0001.ORTS)
THE QBO Table has a field labeled NIIN AND RIC. THE KCA0001.ORTS table has a field named SERVICE and OWN_RIC.
I Join the tables by QBO.RIC and ORTS.OWN_RIC. My dilemma is that under the NIIN field multiple rows can be identical but have different values for RIC.
Example:
NIIN RIC
123455 A
122222 B
123456 C
122222 A
I want to query a distinct count for NIINS that separates by the different service where it does not overlap. So example NIIN should only find distinct values only associated with A where the same NIIN is not found in B,C,D etc.
SELECT D.SERVICE, COUNT(C.NIIN)
FROM DDS2ENVR.QBO C
JOIN KCA0001.ORTS D ON D.OWN_RIC = C.RIC
WHERE C.SITE_ID = ('HEAA')
GROUP BY D.SERVICE
HAVING COUNT(DISTINCT C.NIIN) > 1
Please ask questions if this does not make any sense.
Using Not Exists
SELECT D.SERVICE, COUNT(C.NIIN)
FROM DDS2ENVR.QBO C
JOIN KCA0001.ORTS D ON D.OWN_RIC = C.RIC
WHERE C.SITE_ID = ('HEAA')
and NOT EXISTS (Select 1 from DDS2ENVR.QBO C1 where C1.NIIN = C.NIIN and C1.RIC <> C.RIC)
GROUP BY D.SERVICE
HAVING COUNT(DISTINCT C.NIIN) > 1
Also if the table DDS2ENVR.QBO doesn't contain duplicates and your dbms supports CTE
With cte as
(Select NIIN from DDS2ENVR.QBO group by NIIN having count(*) = 1)
SELECT D.SERVICE, COUNT(C.NIIN)
FROM DDS2ENVR.QBO C
JOIN KCA0001.ORTS D ON D.OWN_RIC = C.RIC
WHERE C.SITE_ID = ('HEAA')
and C.NIIN in (Select * from cte)
GROUP BY D.SERVICE
HAVING COUNT(DISTINCT C.NIIN) > 1

How to find rows that have one equal value and one different value from the table

I have the following table:
ID Number Revision
x y 0
x y 1
z w 0
a w 0
a w 1
b m 0
b m 0
I need to return rows that for the same Number thare are more then one ID with the same Revision.Number can be "Null" and I don't need those values.
The output should be:
z w 0
a w 0
I have tried the following query:
SELECT a.id,a.number,a.revision,
FROM table a INNER JOIN
(SELECT id, number, revision FROM table where number > '0'
GROUP BY number HAVING COUNT(*) > 1
) b ON a.revision = b.revision AND a.id != b.id
A little addition- I have rows in my table with the same Number, ID and Revision- I don't need those rows in my query to be displayed!
It is not working! Please help me to figure out how to fix it.
Thanks.
Select t.Id,s.number,t.revision
from (Select number,count(*) 'c'
from table t1
where revision=0
group by number
having count(*) > 1
) s join table t on t.number= s.number
where revision = 0
Another simple approach:
SELECT DISTINCT b.id, b.Number, b.Revision
FROM tbl a
INNER JOIN tbl b
ON a.ID != b.ID AND a.Number = b.Number AND a.Revision = b.Revision;
This is tested in MySql 5, syntax might differ slightly.
You are not that far away with your query:
SELECT a.id,a.number,a.revision
FROM table a
JOIN (
-- multiple id for the same number and revision
SELECT number, revision
FROM table
GROUP BY number, revision
HAVING COUNT(*) > 1
) b
ON a.revision = b.revision
AND a.number = b.number
Untested, but you should get the idea. If your sql-server is a resent version you can solve this with OLAP functions as well.
To filter out rows where the whole row is duplicated we can select only unique rows via group by and having:
SELECT a.id,a.number,a.revision
FROM table a
JOIN (
-- multiple id for the same number and revision
SELECT number, revision
FROM table
GROUP BY number, revision
HAVING COUNT(*) > 1
) b
ON a.revision = b.revision
AND a.number = b.number
GROUP BY a.id,a.number,a.revision
HAVING COUNT(1) = 1

Replace no result

I have a query like this:
SELECT TV.Descrizione as TipoVers,
sum(ImportoVersamento) as ImpTot,
count(*) as N,
month(DataAllibramento) as Mese
FROM PROC_Versamento V
left outer join dbo.PROC_TipoVersamento TV
on V.IDTipoVersamento = TV.IDTipoVersamento
inner join dbo.PROC_PraticaRiscossione PR
on V.IDPraticaRiscossioneAssociata = PR.IDPratica
inner join dbo.DA_Avviso A
on PR.IDDatiAvviso = A.IDAvviso
where DataAllibramento between '2012-09-08' and '2012-09-17' and A.IDFornitura = 4
group by V.IDTipoVersamento,month(DataAllibramento),TV.Descrizione
order by V.IDTipoVersamento,month(DataAllibramento)
This query must always return something. If no result is produced a
0 0 0 0
row must be returned. How can I do this. Use a isnull for every selected field isn't usefull.
Use a derived table with one row and do a outer apply to your other table / query.
Here is a sample with a table variable #T in place of your real table.
declare #T table
(
ID int,
Grp int
)
select isnull(Q.MaxID, 0) as MaxID,
isnull(Q.C, 0) as C
from (select 1) as T(X)
outer apply (
-- Your query goes here
select max(ID) as MaxID,
count(*) as C
from #T
group by Grp
) as Q
order by Q.C -- order by goes to the outer query
That will make sure you have always at least one row in the output.
Something like this using your query.
select isnull(Q.TipoVers, '0') as TipoVers,
isnull(Q.ImpTot, 0) as ImpTot,
isnull(Q.N, 0) as N,
isnull(Q.Mese, 0) as Mese
from (select 1) as T(X)
outer apply (
SELECT TV.Descrizione as TipoVers,
sum(ImportoVersamento) as ImpTot,
count(*) as N,
month(DataAllibramento) as Mese,
V.IDTipoVersamento
FROM PROC_Versamento V
left outer join dbo.PROC_TipoVersamento TV
on V.IDTipoVersamento = TV.IDTipoVersamento
inner join dbo.PROC_PraticaRiscossione PR
on V.IDPraticaRiscossioneAssociata = PR.IDPratica
inner join dbo.DA_Avviso A
on PR.IDDatiAvviso = A.IDAvviso
where DataAllibramento between '2012-09-08' and '2012-09-17' and A.IDFornitura = 4
group by V.IDTipoVersamento,month(DataAllibramento),TV.Descrizione
) as Q
order by Q.IDTipoVersamento, Q.Mese
Use COALESCE. It returns the first non-null value. E.g.
SELECT COALESCE(TV.Desc, 0)...
Will return 0 if TV.DESC is NULL.
You can try:
with dat as (select TV.[Desc] as TipyDesc, sum(Import) as ToImp, count(*) as N, month(Date) as Mounth
from /*DATA SOURCE HERE*/ as TV
group by [Desc], month(Date))
select [TipyDesc], ToImp, N, Mounth from dat
union all
select '0', 0, 0, 0 where (select count (*) from dat)=0
That should do what you want...
If it's ok to include the "0 0 0 0" row in a result set that has data, you can use a union:
SELECT TV.Desc as TipyDesc,
sum(Import) as TotImp,
count(*) as N,
month(Date) as Mounth
...
UNION
SELECT
0,0,0,0
Depending on the database, you may need a FROM for the second SELECT. In Oracle, this would be "FROM DUAL". For MySQL, no FROM is necessary

Multiple MAX values select using inner join

I have query that work for me only when values in the StakeValue don't repeat.
Basically, I need to select maximum values from SI_STAKES table with their relations from two other tables grouped by internal type.
SELECT a.StakeValue, b.[StakeName], c.[ProviderName]
FROM SI_STAKES AS a
INNER JOIN SI_STAKESTYPES AS b ON a.[StakeTypeID] = b.[ID]
INNER JOIN SI_PROVIDERS AS c ON a.[ProviderID] = c.[ID] WHERE a.[EventID]=6
AND a.[StakeGroupTypeID]=1
AND a.StakeValue IN
(SELECT MAX(d.StakeValue) FROM SI_STAKES AS d
WHERE d.[EventID]=a.[EventID] AND d.[StakeGroupTypeID]=a.[StakeGroupTypeID]
GROUP BY d.[StakeTypeID])
ORDER BY b.[StakeName], a.[StakeValue] DESC
Results for example must be:
[ID] [MaxValue] [StakeTypeID] [ProviderName]
1 1,5 6 provider1
2 3,75 7 provider2
3 7,6 8 provider3
Thank you for your help
There are two problems to solve here.
1) Finding the max values per type. This will get the Max value per StakeType and make sure that we do the exercise only for the wanted events and group type.
SELECT StakeGroupTypeID, EventID, StakeTypeID, MAX(StakeValue) AS MaxStakeValue
FROM SI_STAKES
WHERE Stake.[EventID]=6
AND Stake.[StakeGroupTypeID]=1
GROUP BY StakeGroupTypeID, EventID, StakeTypeID
2) Then we need to get only one return back for that value since it may be present more then once.
Using the Max Value, we must find a unique row for each I usually do this by getting the Max ID is has the added advantage of getting me the most recent entry.
SELECT MAX(SMaxID.ID) AS ID
FROM SI_STAKES AS SMaxID
INNER JOIN (
SELECT StakeGroupTypeID, EventID, StakeTypeID, MAX(StakeValue) AS MaxStakeValue
FROM SI_STAKES
WHERE Stake.[EventID]=6
AND Stake.[StakeGroupTypeID]=1
GROUP BY StakeGroupTypeID, EventID, StakeTypeID
) AS SMaxVal ON SMaxID.StakeTypeID = SMaxVal.StakeTypeID
AND SMaxID.StakeValue = SMaxVal.MaxStakeValue
AND SMaxID.EventID = SMaxVal.EventID
AND SMaxID.StakeGroupTypeID = SMaxVal.StakeGroupTypeID
3) Now that we have the ID's of the rows that we want, we can just get that information.
SELECT Stakes.ID, Stakes.StakeValue, SType.StakeName, SProv.ProviderName
FROM SI_STAKES AS Stakes
INNER JOIN SI_STAKESTYPES AS SType ON Stake.[StakeTypeID] = SType.[ID]
INNER JOIN SI_PROVIDERS AS SProv ON Stake.[ProviderID] = SProv.[ID]
WHERE Stake.ID IN (
SELECT MAX(SMaxID.ID) AS ID
FROM SI_STAKES AS SMaxID
INNER JOIN (
SELECT StakeGroupTypeID, EventID, StakeTypeID, MAX(StakeValue) AS MaxStakeValue
FROM SI_STAKES
WHERE Stake.[EventID]=6
AND Stake.[StakeGroupTypeID]=1
GROUP BY StakeGroupTypeID, EventID, StakeTypeID
) AS SMaxVal ON SMaxID.StakeTypeID = SMaxVal.StakeTypeID
AND SMaxID.StakeValue = SMaxVal.MaxStakeValue
AND SMaxID.EventID = SMaxVal.EventID
AND SMaxID.StakeGroupTypeID = SMaxVal.StakeGroupTypeID
)
You can use the over clause since you're using T-SQL (hopefully 2005+):
select distinct
a.stakevalue,
max(a.stakevalue) over (partition by a.staketypeid) as maxvalue,
b.staketypeid,
c.providername
from
si_stakes a
inner join si_stakestypes b on
a.staketypeid = b.id
inner join si_providers c on
a.providerid = c.id
where
a.eventid = 6
and a.stakegrouptypeid = 1
Essentially, this will find the max a.stakevalue for each a.staketypeid. Using a distinct will return one and only one row. Now, if you wanted to include the min a.id along with it, you could use row_number to accomplish this:
select
s.id,
s.maxvalue,
s.staketypeid,
s.providername
from (
select
row_number() over (order by a.stakevalue desc
partition by a.staketypeid) as rownum,
a.id,
a.stakevalue as maxvalue,
b.staketypeid,
c.providername
from
si_stakes a
inner join si_stakestypes b on
a.staketypeid = b.id
inner join si_providers c on
a.providerid = c.id
where
a.eventid = 6
and a.stakegrouptypeid = 1
) s
where
s.rownum = 1