I have the following two pseudo queries:
SELECT Sum(a)
FROM b
WHERE c
and
SELECT Sum(d)
FROM b
WHERE e
I want to sum these queries together to one value but I can't figure out the syntax. Note the FROM statement is the same ("b"). I've tried a UNION query but this gives me two values...
You can use iif() inside sum() where you apply the conditions:
select sum(iif(c, a, 0)) + sum(iif(e, d, 0))
from b
Since both queries will always return a single record, you could alternatively cross join the two subqueries and simply add the results, e.g.:
select r1 + r2 from
(select sum(a) as r1 from b where c) t1,
(select sum(d) as r2 from b where e) t2
Try
SELECT SUM(col1)
FROM
(
SELECT Sum(a) col1
FROM b
WHERE c
UNION
SELECT Sum(d) col1
FROM b
WHERE e) t
Please try the following
Select sum(sumVal)
FROM
(SELECT Sum(a) sumVal
FROM b
where c
UNION
SELECT Sum(d) sumVal
FROM e
where f
)
Try to use this :
;WITH
t1 as ( select sum(a) as a from b where c>20)
,
t2 as (select sum(d) as d from b where e is not null)
select t1.b1+t2.c2 as s from t1 inner join t2 on t1.b1 != t2.c2
Related
Hay All,
is it possible to run more than 1 select statement after using with?
first select statement works fine, as soon as i add another select statement i got a error.
with
a as (select a,b,c from Table1 with(readuncommitted)),
b as (select d,e,f from Table2 with(readuncommitted))
select * from a
select * from b
expected output:
Table 1
a
Table 2
b
Well the way CTEs will behave is that they will only be in scope for the first query, but not the second. You could perhaps do a union query here:
SELECT a, b, c, 'Table1' AS src FROM a
UNION ALL
SELECT d, e, f, 'Table2' FROM b;
Or, you could move the b CTE to before the second query:
WITH a AS (
SELECT a, b, c
FROM Table1
WITH(readuncommitted)
)
SELECT * FROM a;
WITH b AS (
SELECT d, e, f
FROM Table2
WITH(readuncommitted)
)
SELECT * FROM b;
hay DasD,
You can not use multiple select for cte, but you can use more than one CTE like this.
with
a as (select a,b,c from Table1 with(readuncommitted)),
b as (select d,e,f from Table2 with(readuncommitted))
select * from a,b
You have to explain to the database, what you wantfrom bith tables.
as both have the same structure you can use UNION to join them vertically
with
a as (select a,b,c from Table1 with(readuncommitted)),
b as (select d,e,f from Table2 with(readuncommitted))
select * from a
UNION
select * from b
From the docs:
"A CTE must be followed by a single SELECT, INSERT, UPDATE, or DELETE statement that references some or all the CTE columns."
Source
There is a way to return the sub-select and return manipulate that depend on this field ?
For example, can I do something like this:
select a, (select top 1 b from b) as b, (a * b) as c
from a
select a, b, (a * b) as c
from (
select a, (select top 1 b from b) as b
from a
) x
Put the subquery in the from clause:
select a.a, b.b, (a.a * b.b) as c
from a cross join
(select top 1 b from b) b;
Let's say I would like to pull the fields dim,a,b,c,d from 2 tables which one contains a,b and the other contains c,d.
I'm wondering if there's a preferred way (between the following) to do it - Performance wise:
1:
select t1.dim,a,b,c,d
from
(select dim,sum(a) as a,sum(b)as b from t1 group by dim)t1
join
(select dim,sum(c) as c,sum(d) as d from t2 group by dim)t2
on t1.dim=t2.dim;
2:
select dim,sum(a) as a,sum(b) as b,sum(c) as c,sum(d) as d
from
(
select dim,a,b,null as c, null as d from t1
union
select dim,null as a, null as b, c, d from t2
)a
group by dim
Of course when handling a large amount of data (5-30M records at the final query).
Thanks!
The first method filters would any dim values that are not in both tables. union is inefficient. So, neither is appealing.
I would go for:
select dim, sum(a) as a, sum(b) as b, sum(c) as c, sum(d) as d
from (select dim, a, b, null as c, null as d from t1
union all
select dim, null as a, null as b, c, d from t2
) a
group by dim;
You could also pre-aggregate the values in each subquery. Or use full outer join for the first method.
I am trying to learn some SQL and what I want to do is simply select some rows from a table according to some criteria.
So, I am trying something like:
Select * from mytable where id=1090 as A, Select * from mytable where id=1075 as B;
I need to keep them as distinct entities (A and B) in my example, so that I can do something like:
Select A.col, B.row from A, B where <some criteria>
I am unable to figure out how to put all this together in a SQL query
You can do this magic to achieve what you want, if I understand you correctly. This will return rows side by side, don't know how to explain:
;with a as(select *, row_number() over(order by(select null)) rn
from tableA where id = 1090),
b as(select *, row_number() over(order by(select null)) rn
from tableB where id = 1075)
select a.*, b.*
from a
full join b on a.rn = b.rn
If first select returns 4 rows and second 2 rows the output will be something like:
A(rn, cols) B(rn, cols)
1 ......... 1 .........
2 ......... 2 .........
3 ......... NULL
4 ......... NULL
select A.*, B.*
from
(Select * from mytable where id=1090) as A
join
(Select * from mytable where id=1075) as B ON <some criteria>
I'm looking to do something like this:
SELECT a, b, c, d FROM someTable WHERE
WHERE a in (SELECT testA FROM otherTable);
Only I want to be able to test if 2 columns exist in a sub select of 2 columns.
SELECT a, b, c, d FROM someTable WHERE
WHERE a OR b in (SELECT testA, testB FROM otherTable);
We are using MS SQL Server 2012
Try this
SELECT a, b, c, d
FROM someTable WHERE
WHERE a IN (SELECT testA FROM otherTable)
OR b IN (SELECT testB FROM otherTable)
or
SELECT a, b, c, d
FROM someTable WHERE
WHERE EXISTS
(SELECT NULL
FROM otherTable
WHERE testA = a OR testB = a
OR testA = b OR testB = b)
UPDATE:
Maybe you need to add index on testB column, if you have bad performance.
Also another option to use CROSS APPLY for MS SQL
SELECT a, b, c, d
FROM someTable ST
CROSS APPLY (
SELECT 1
FROM otherTable OT
WHERE OT.testA = ST.a OR OT.testB = ST.b
)
If any of this won't work, try using UNION. Mostly UNION gives better performance than OR
SELECT a, b, c, d
FROM someTable WHERE
WHERE a IN (SELECT testA FROM otherTable)
UNION
SELECT a, b, c, d
FROM someTable WHERE
WHERE b IN (SELECT testB FROM otherTable)
UPDATE 2:
For further reading on OR and UNION differences
Why is UNION faster than an OR statement
Try this..
SELECT a, b, c, d
FROM someTable
WHERE Exists
(
SELECT 1
FROM otherTable
Where a = testA OR b = testB
)
If I'm understanding your question correctly, LEFT JOIN is probably the way to go here:
SELECT a, b, c, d
FROM TableA ta
LEFT JOIN TableB tb
ON ta.a = tb.a
AND ta.b = tb.b
WHERE tb.a IS NOT NULL
AND tb.c IS NOT NULL
You could also use UNION and INNER JOIN:
SELECT a, b, c, d
FROM someTable
INNER JOIN OtherTable OT on someTable.B = OT.testB
UNION
SELECT a, b, c, d
FROM someTable
INNER JOIN OtherTable OT ON someTable.A= OT.testA
Note that the JOIN approach should be orders of magnitude faster if you have an index on the column
Joins seems to be one option, have you thought about using them with a Union?
SELECT a, b, c, d
FROM someTable
INNER JOIN OtherTable OT on someTable.B = OT.testB
UNION
SELECT a, b, c, d
FROM someTable
INNER JOIN OtherTable OT ON someTable.A= OT.testA