I have this query but I need the second WHERE condition to be dependent on a value in the set:
SELECT TABLE1.*, TABLE2.*
FROM TABLE1, TABLE2
WHERE TABLE1.ID = TABLE2.ID
AND TABLE1.TIMESTAMP > DATEADD(D,-5,GETDATE())
So I was going for something like this which doesn't work (because of the '>'):
SELECT TABLE1.*, TABLE2.*
FROM TABLE1, TABLE2
WHERE TABLE1.ID = TABLE2.ID
AND CASE WHEN TABLE1.TRIGGER = 'TRUE' THEN TABLE1.TIMESTAMP > DATEADD(D,-5,GETDATE()) END
I've looked around but I was only able to find examples where the intention was to manipulate numerical info. Does anyone have any ideas?
Change this:
AND TABLE1.TIMESTAMP > DATEADD(D,-5,GETDATE())
To:
AND (TABLE1.TRIGGER <> 'TRUE' or (TABLE1.TRIGGER = 'TRUE' AND TABLE1.TIMESTAMP > DATEADD(D,-5,GETDATE()))
This will either be "and true" if TABLE1.TRIGGER is not equal to TRUE, or it will perform your extra conditional check (TABLE1.TIMESTAMP > ...) if it is equal to TRUE.
CASE results in a value, so you need to do something with it, e.g. compare it to another value:
SELECT TABLE1.*, TABLE2.*
FROM TABLE1, TABLE2
WHERE TABLE1.ID = TABLE2.ID AND
CASE
WHEN TABLE1.TRIGGER = 'TRUE' THEN 1
WHEN TABLE1.TIMESTAMP > DATEADD(D,-5,GETDATE()) THEN 1
ELSE 0
END = 1
Related
I have two tables shown below. I want to create a new variable (VALUE) based on the logic below and show results in a 3rd table? How can I do this in T SQL?
TABLE_1
ID, DATE
TABLE_2
ID, DATE1, DATE2
Logic to set VALUE:
FOR ALL TABLE_1.ID
IF TABLE_1.DATE IS BETWEEN TABLE_2.DATE1 AND TABLE_2.DATE2
THEN VALUE = 1
ELSE VALUE = 0
IF TABLE_1.ID NOT IN TABLE_2
THEN VALUE = NULL
If you want to see the results for all rows where table_1.id = table_2.id (and table_1 rows that do not have a match on id), then we can use a left join and a case expression:
select
t.id
, t.date
, IsBetween = case
when t.date between t2.Date1 and t2.Date2
then 1
when t2.id is null
then null
else 0
end
, t2.*
from table_1 as t
left join table_2 as t2
on t.id = t2.id
If you only want one row for each row in table_1, and want to know if table_1.data is between any corresponding row in table_2 or not, then we can use a outer apply to select top 1 and a case expression:
select
t.id
, t.date
, IsBetween = case
when t.date between x.Date1 and x.Date2
then 1
when x.id is null
then null
else 0
end
from table_1 t
outer apply (
select top 1 t2.*
from table_2 t2
order by case
when t.date between t2.Date1 and t2.Date2
then 0
else 1
end
) as x
Below sample query is a part of my main query. I found SORT operator in below query is consuming 30% of the cost.
To avoid SORT, there is need of creation of Indexes. Is there any other way to optimize this code.
SELECT TOP 1 CONVERT( DATE, T_Date) AS T_Date
FROM TableA
WHERE ID = r.ID
AND Status = 3
AND TableA_ID >ISNULL((
SELECT TOP 1 TableA_ID
FROM TableA
WHERE ID = r.ID
AND Status <> 3
ORDER BY T_Date DESC
), 0)
ORDER BY T_Date ASC
Looks like you can use not exists rather than the sorts. I think you'll probably get a better performance boost by use a CTE or derived table instead of the a scalar subquery.
select *
from r ... left outer join
(
select ID, min(t_date) as min_date from TableA t1
where status = 3 and not exists (
select 1 from TableA t2
where t2.ID = t1.ID
and t2.status <> 3 and t2.t_date > t1.t_date
)
group by ID
) as md on md.ID = r.ID ...
or
select *
from r ... left outer join
(
select t1.ID, min(t1.t_date) as min_date
from TableA t1 left outer join TableA t2
on t2.ID = t1.ID and t2.status <> 3
where t1.status = 3 and t1.t_date < t2.t_date
group by t1.ID
having count(t2.ID) = 0
) as md on md.ID = r.ID ...
It also appears that you're relying on an identity column but it's not clear what those values mean. I'm basically ignoring it and using the date column instead.
Try this:
SELECT TOP 1 CONVERT( DATE, T_Date) AS T_Date
FROM TableA a1
LEFT JOIN (
SELECT ID, MAX(TableA_ID) AS MaxAID
FROM TableA
WHERE Status <> 3
GROUP BY ID
) a2 ON a2.ID = a1.ID AND a1.TableA_ID > coalesce(a2.MAXAID,0)
WHERE a1.ID = r.ID AND a1.Status = 3
ORDER BY T_Date ASC
The use of TOP 1 in combination with the unexplained r alias concern me. There's almost certainly a MUCH better way to get this data into your results that doesn't involve doing this in a sub query (unless this is for an APPLY operation).
I am trying to some sql code that combines information from 2 tables and uses case but it is not returning all the data.
SELECT TABLE1.PRODUCT, TABLE1.TYPE, TABLE1.AMOUNT,
(CASE
WHEN TABLE1.PRODUCT = 'RADIO'
THEN 100
ELSE 200
END) AS PRODUCT_CODE,
(CASE
WHEN TABLE1.TYPE = 'NEW'
THEN 'Y'
ELSE TABLE2.AGE
END) AS STATUS
FROM TABLE1 LEFT JOIN TABLE 2 ON TABLE1.TID = TABLE2.TID
WHERE TABLE1.DATE > '01-AUG-15'
AND TABLE2.DATE = '02-AUG-15'
The problem I am having is that I need all records from table1 and those that apply from table2 but when the query is returning less rows than there are in table 1.
Your problem is here
AND TABLE2.DATE = '02-AUG-15'
If Table2.Date is null due to the left join, this condition fails, which is why you are getting less rows than Table1. Adding a condition to the where clause from a left joined table is effectively turning it into an inner join.
Try either
AND (TABLE2.DATE = '02-AUG-15' OR TABLE2.DATE IS NULL)
(this assumes that TABLE2.DATE is not nullable) or put the condition in the join statement instead
FROM TABLE1 LEFT JOIN TABLE 2 ON TABLE1.TID = TABLE2.TID AND TABLE2.DATE = '02-AUG-15'
Is it possible to use the value of EXISTS as part of a query?
(Please note: unfortunately due to client constraints, I need SQLServer 2005 compatible answers!)
So when returning a set of results, one of the columns is a boolean value which states whether the subquery would return any rows.
For example, I want to return a list of usernames and whether a different table contains any rows for each user. The following is not syntactically correct, but hopefully gives you an idea of what I mean...
SELECT T1.[UserName],
(EXISTS (SELECT *
FROM [AnotherTable] T2
WHERE T1.[UserName] = T2.[UserName])
) AS [RowsExist]
FROM [UserTable] T1
Where the resultant set contains a column called [UserName] and boolean column called [RowsExist].
The obvious solution is to use a CASE, such as below, but I wondered if there was a better way of doing it...
SELECT T1.[UserName],
(CASE (SELECT COUNT(*)
FROM [AnotherTable] T2
WHERE T1.[UserName] = T2.[UserName]
)
WHEN 0 THEN CAST(0 AS BIT)
ELSE CAST(1 AS BIT) END
) AS [RowsExist]
FROM [UserTable] T1
Your second query isn't valid syntax.
SELECT T1.[UserName],
CASE
WHEN EXISTS (SELECT *
FROM [AnotherTable] T2
WHERE T1.[UserName] = T2.[UserName]) THEN CAST(1 AS BIT)
ELSE CAST(0 AS BIT)
END AS [RowsExist]
FROM [UserTable] T1
Is generally fine and will be implemented as a semi join.
The article Subqueries in CASE Expressions discusses this further.
In some cases a COUNT query can actually perform better though as discussed here
I like the other guys sql better but i just wrote this:
with bla as (
select t2.username, isPresent=CAST(1 AS BIT)
from t2
group by t2.username
)
select t1.*, isPresent = isnull(bla.isPresent, CAST(0 AS BIT))
from t1
left join blah on t1.username=blah.username
From what you wrote here I would alter your first query into something like this
SELECT
T1.[UserName], ISNULL(
(
SELECT
TOP 1 1
FROM [AnotherTable]
WHERE EXISTS
(
SELECT
1
FROM [AnotherTable] AS T2
WHERE T1.[UserName] = T2.[UserName]
)
), 0)
FROM [UserTable] T1
But actually if you use TOP 1 1 you would not need EXISTS, you could also write
SELECT
T1.[UserName], ISNULL(
(
SELECT
TOP 1 1
FROM [AnotherTable] AS T2
WHERE T1.[UserName] = T2.[UserName]
), 0)
FROM [UserTable] T1
I'm trying to select all records from a table "Table1" but I want a new column called "HasException" that contains a "0" or a "1". "HasException" must be "0" if the count of row matching the current Id from "Table2" is equal to 0, else it returns 1.
Here's what I've done so far, but it doesn't works:
SELECT *,
CONVERT(bit, (CASE WHEN (SELECT count(Id) FROM Table2 WHERE Table1.Id=Table2.Id) = 0 THEN 0 ELSE 1 END)) AS HasException
FROM Table1
You want to join the tables (and group on ID) before you can compare the two values like this:
SELECT dbo.Table_1.*,
CASE WHEN COUNT(dbo.Table_2.ID) = 0 THEN
0
ELSE
1
END
AS HasException
FROM dbo.Table_1 LEFT OUTER JOIN
dbo.Table_2 ON dbo.Table_1.ID = dbo.Table_2.ID
GROUP BY dbo.Table_1.ID
perhaps something like, assuming you meant table2?
SELECT *,
CAST(CASE WHEN COUNT(table2.id) = 0 THEN 0 ELSE 1 END AS bit) AS HasException
FROM
Table1
LEFT JOIN
Table2 ON Table1.Id=Table2.Id
GROUP BY
Table1.id
select
T1.*,
case when T2.Id is null then 0 else 1 end as HasException
from Table1 as T1
left outer join
(
select distinct Id
from Table2
) as T2
on T1.Id = T2.Id