Case-when w.r.to Count in sql server - sql-server

I am getting error in the below sql query.
if count is >1 i need to execute when statement, if not else statement.
SELECT CASE
WHEN (COUNT(VALUE) FROM TABLE1 WHERE ID=111)>1 )
THEN
SELECT VALUE FROM TABLE2 WHERE ID=111
ELSE
SELECT 2
Please help

Try this:
if (select count(*) from table1 where id = 111 group by id) > 1
select value from table2 where id = 111
else
select 2
Demo
The same thing, written using case when...
select
case
when (select count(*) from table1 where id = 111 group by id) > 1 then value
else 2
end
from table2
where id = 111

Try this sample code
DECLARE #Table1 TABLE
(
id INT,
value INT
)
INSERT #Table1
VALUES(1,
10)
INSERT #Table1
VALUES(2,
20)
DECLARE #TABLE2 TABLE
(
id INT,
c2 INT
)
INSERT #TABLE2
VALUES(1,
11 )
INSERT #TABLE2
VALUES(2,
22 )
SELECT CASE
WHEN (SELECT count(value)
FROM #Table1) > 0 THEN (SELECT T2.c2
FROM #TABLE2 T2
WHERE T1.id = T2.id)
ELSE (SELECT T2.id
FROM #TABLE2 T2
WHERE T1.id = T2.id)
END
FROM #Table1 t1

IF EXISTS(SELECT TOP 1 1 FROM TABLE1 WHERE ID='111' HAVING COUNT(VALUE)>1)
BEGIN
SELECT VALUE FROM TABLE2 WHERE ID=111
END
ELSE
BEGIN
SELECT 2
END

Related

T-SQL Group by multiple batches of 2

So the wonderful people here on stackoverflow helped me with a "find consecutive failures" type query. (Status =4 is a failure). I thought I had cracked the second part of my problem because my test case seems to work fine but whenever I run it on our test environment I get dodgy results, so I must be doing something wrong. The goal is to find X number of consecutive failures. So the below is set to find 2 consecutive failures. I'm using SQL Server 2008 R2
DECLARE #t TABLE (
[InstructionId] INT,
[InstructionDetailId] INT,
[Sequence] INT,
[Status] INT
)
INSERT INTO #t SELECT 222,111,1, 2
INSERT INTO #t SELECT 222,112,2,2
INSERT INTO #t SELECT 222,113,3,4
INSERT INTO #t SELECT 222,114,4,4
INSERT INTO #t SELECT 222,115,5,2
INSERT INTO #t SELECT 222,116,6,4
INSERT INTO #t SELECT 222,117,7,2
INSERT INTO #t SELECT 222,118,8,4
INSERT INTO #t SELECT 222,119,9,4
INSERT INTO #t SELECT 222,120,10,2
INSERT INTO #t SELECT 222,121,11,2
INSERT INTO #t SELECT 222,124,12,4
INSERT INTO #t SELECT 222,126,13,4
INSERT INTO #t SELECT 222,128,14,4
INSERT INTO #t SELECT 223,126,13,4
INSERT INTO #t SELECT 223,128,14,4
INSERT INTO #t SELECT 223,129,15,2
INSERT INTO #t SELECT 223,130,16,4
INSERT INTO #t SELECT 224,111,17,4
INSERT INTO #t SELECT 224,112,18,4
INSERT INTO #t SELECT 223,160,33,4
INSERT INTO #t SELECT 223,161,34,4
INSERT INTO #t SELECT 223,162,35,4
INSERT INTO #t SELECT 223,163,40,4
;with HardcoreCTE AS
(
select t.*,
t.[Sequence] - ROW_NUMBER() OVER(PARTITION BY t.instructionId ORDER BY
t.InstructionDetailId) AS ItemCount
from #t t outer apply
( select top (1) t1.*
from #t t1
where t1.InstructionId = t.InstructionId and
t1.Sequence < t.Sequence
order by t1.Sequence desc
) t1 outer apply
( select top (1) t2.*
from #t t2
where t2.InstructionId = t.InstructionId and
t2.Sequence > t.Sequence
order by t2.Sequence
) t2
where t.status = 4 and (t.status = t1.status or t.status = t2.status)
)
,
HardCoreCTE2
AS
(
select *, Count(1) OVER(PARTITION BY ItemCount) AS ItemCount2 from
HardcoreCTE
)
select * from HardCoreCTE2
where ItemCount2 =2
So the above works brilliants to find results where there are specifically only 2 consecutive failures with these
results:
Now from the above results the only ones it finds are the records where there are 2 consecutive failures but whenever I convert the above to the actual test environment tables it doesn't seem to work.
Test Env Results: As you can see for the "InstructionId" of 2518380 it brought back one record and the for "InstructionId" 2614351. It's meant to bring back sets of 2 records.
Test Env Query: (Pretty much identical)
;with InitialDataCTE
AS
(
SELECT Instruction.InstructionID,InstructionDetail.InstructionDetailID,
InstructionDetail.InstructionDetailStatusID AS [Status],
InstructionDetail.Sequence
FROM Instruction INNER JOIN
InstructionDetail ON Instruction.InstructionID =
InstructionDetail.InstructionID
where InstructionDetailStatusID =4
and InstructionDetail.PaymentDateOriginal between '2015-01-05'
AND '2018-09-08'
),
HardCoreCTE
AS
(
select t.*,
t.Sequence - ROW_NUMBER() OVER(PARTITION BY t.instructionId ORDER BY
t.InstructionDetailId) AS ItemCount
from InitialDataCTE t outer apply
( select top (1) t1.*
from InitialDataCTE t1
where t1.InstructionId = t.InstructionID and
t1.Sequence < t.Sequence
order by t1.Sequence desc
) t1 outer apply
( select top (1) t2.*
from InitialDataCTE t2
where t2.InstructionId = t.InstructionId and
t2.Sequence > t.Sequence
order by t2.Sequence
) t2
where t.Status = 4 and (t.Status = t1.Status or t.Status = t2.Status)
)
,
HardCoreCTE2
AS
(
select *, Count(1) OVER(PARTITION BY ItemCount) AS ItemCount2 from
HardCoreCTE
)
select * from HardCoreCTE2
where ItemCount2 =2
order by InstructionID, Sequence
Really appreciate if someone can tell me where I am going wrong, I've been messing around with variations of the Count(*) but nothing successful yet. Thanx alot
I came to the next query:
with
a as (
select *,
row_number() over(partition by InstructionId order by Sequence)-
row_number() over(partition by InstructionId, [Status] order by Sequence) g
from #t
),
b as (
select *,
count(*) over(partition by InstructionId, [Status], g) c
from a
where [Status] = 4
)
select *
from b
where c > 2
order by 1, 3;
For your test data, I got the following result:
InstructionId InstructionDetailId Sequence Status g c
222 224 312 4 6 3
222 226 413 4 6 3
222 228 514 4 6 3
223 161 84 4 2 3
223 162 95 4 2 3
223 163 140 4 2 3
You can test this query here.

T-SQL - Compare two tables and display result as Available on Both, table1 only and table2 only

I have 2 tables and structure is same on both tables.
Table 1:
ID Name Phone
1 xxx 111
2 yyy 222
Table 2:
ID Name Phone
1 xxx 111
3 zzz 333
I need to compare these two tables and display the results (based on ID column- where condition ID) as
Available in both tables
Table1 only
Table2 only
This should be like this,
ID Name Phone Status
----------------------------------------
1 xxx 111 Available in both
2 yyy 222 Available in T1 only
3 zzz 333 Available in T2 only
using HASHBYTES :Demo Here ..you dont need to consume table mutiple times,but only once
;with cte
as
(
select id,name,phone,hashbytes('sha1',concat(id,name,phone) )as tb1
from #t1
)
select isnull(c.id,b.id) as id,
isnull(c.name,b.name) as name,
isnull(c.phone,b.phone) as phone,
case when c.tb1 is null then 'exists in second table only'
when c.tb1 is not null and b.tb1 is not null then 'exists in both'
when b.tb1 is null then 'exists in first table only'
end as 'exidts' from cte c
full join
(
select id,name,phone,hashbytes('sha1',concat(id,name,phone) )as tb1
from #t2
) b
on
b.tb1=c.tb1
Try this:
declare #table1 table
(
name varchar(10),
phone varchar(10)
)
declare #table2 table
(
name varchar(10),
phone varchar(10)
)
INSERT INTO #table1 VALUES('xxx','111')
INSERT INTO #table1 VALUES('yyy','222')
INSERT INTO #table2 VALUES('xxx','111')
INSERT INTO #table2 VALUES('zzz','333')
SELECT t1.name, t1.phone, 'Available on both' FROM
#table1 t1 INNER JOIN #table2 t2
ON t1.name = t2.name and t1.phone = t2.phone
UNION
SELECT name, phone, 'Available on T1 only' FROM
#table1 t1 WHERE NOT EXISTS
(SELECT 1 FROM #table2 t2
WHERE t1.name = t2.name and t1.phone = t2.phone)
UNION
SELECT name, phone, 'Available on T2 only' FROM
#table2 t2 WHERE NOT EXISTS
(SELECT 1 FROM #table1 t1
WHERE t1.name = t2.name and t1.phone = t2.phone)
You can use combination of FULL JOIN and IS NULL to check availability from both tables -
SELECT ISNULL(t1.id, t2.id) AS Id
, ISNULL(t1.name, t2.name) AS Name
, ISNULL(t1.phone, t2.phone) AS Phone
, CASE
WHEN t1.id IS NULL THEN 'Available in T2 only'
WHEN t2.id IS NULL THEN 'Available in T1 only'
ELSE 'Available in both'
END AS Status
FROM Table1 AS t1
FULL JOIN Table2 AS t2 ON (t2.id = t1.id);
As this query uses only one JOIN operation and no sub queries it is very fast.
This could work:
CREATE TABLE #T1 ( ID INT, Name VARCHAR(10), Phone VARCHAR(10) )
CREATE TABLE #T2 ( ID INT, Name VARCHAR(10), Phone VARCHAR(10) )
INSERT INTO #T1 VALUES ( 1, 'xxx', '111' ), ( 2, 'yyy', '222' )
INSERT INTO #T2 VALUES ( 1, 'xxx', '111' ), ( 3, 'zzz', '333' )
SELECT #T1.ID, #T1.Name, #T1.Phone, 'Available on both' AS Status
FROM #T1 INNER JOIN #T2 ON #T1.ID = #T2.ID
UNION
SELECT #T1.ID, #T1.Name, #T1.Phone, 'Available on T1 only' AS Status
FROM #T1 LEFT JOIN #T2 ON #T1.ID = #T2.ID
WHERE #T2.ID IS NULL
UNION
SELECT #T2.ID, #T2.Name, #T2.Phone, 'Available on T2 only' AS Status
FROM #T1 RIGHT JOIN #T2 ON #T1.ID = #T2.ID
WHERE #T1.ID IS NULL
DROP TABLE #T1
DROP TABLE #T2

Update sequence based on pattern SQL Server

I was not able to quote correct tile for the question.
Below is my table.
Expected Output : With ID and SequenceNo column. Was unable to upload image.
ID Act SequenceNo1
1 1 1
2 2 NULL
3 3 NULL
4 4 NULL
5 1 5
6 2 NULL
7 3 NULL
8 4 NULL
9 5 NULL
10 6 NULL
11 5 11
12 6 NULL
13 1 13
14 2 NULL
15 3 NULL
16 4 NULL
17 5 NULL
18 6 NULL
19 1 19
20 2 NULL
21 3 NULL
22 4 NULL
23 5 NULL
24 6 NULL
At the start last column SequenceNo is NULL.`
My requirement is to update value of ID column to SequenceNo column whenever new series of Act column is started.
Act column has value of 1 to 6. There can be case where any number from 1 to 6 is missing from Act.
Example1 : ID 1 to 4 - Act is correct but, in next row (ID=5) Act is restarted. Hence need to update SequenceNo column.
Example2 : ID 5 to 10 are correct. But next row (ID=11;Act=5) has new sequence hence need to update SequenceNo column.
CREATE TABLE #tmp
(
ID int
, ScheduleID varchar(50)
,DCNumber VARCHAR(50)
, BuildingID varchar(10)
, StoreNumber int
, [DayOfWeek] int
, [Tm] varchar(10)
,[Act] int
, SequenceNo int
)
INSERT INTO #tmp SELECT 1,'WAS',9003,900301,254,1,'00:00',1,NULL
INSERT INTO #tmp SELECT 2,'WAS',9003,900301,254,1,'00:00',2,NULL
INSERT INTO #tmp SELECT 3,'WAS',9003,900301,254,1,'00:00',3,NULL
INSERT INTO #tmp SELECT 4,'WAS',9003,900301,254,1,'00:00',4,NULL
INSERT INTO #tmp SELECT 5,'WAS',9003,900301,254,2,'00:00',1,NULL
INSERT INTO #tmp SELECT 6,'WAS',9003,900301,254,2,'00:00',2,NULL
INSERT INTO #tmp SELECT 7,'WAS',9003,900301,254,2,'00:00',3,NULL
INSERT INTO #tmp SELECT 8,'WAS',9003,900301,254,2,'00:00',4,NULL
INSERT INTO #tmp SELECT 9,'WAS',9003,900301,254,2,'00:00',5,NULL
INSERT INTO #tmp SELECT 10,'WAS',9003,900301,254,2,'00:00',6,NULL
INSERT INTO #tmp SELECT 11,'WAS',9003,900301,254,3,'00:00',5,NULL
INSERT INTO #tmp SELECT 12,'WAS',9003,900301,254,3,'00:00',6,NULL
INSERT INTO #tmp SELECT 13,'WAS',9003,900301,254,4,'00:00',1,NULL
INSERT INTO #tmp SELECT 14,'WAS',9003,900301,254,4,'00:00',2,NULL
INSERT INTO #tmp SELECT 15,'WAS',9003,900301,254,4,'00:00',3,NULL
INSERT INTO #tmp SELECT 16,'WAS',9003,900301,254,4,'00:00',4,NULL
INSERT INTO #tmp SELECT 17,'WAS',9003,900301,254,5,'00:00',5,NULL
INSERT INTO #tmp SELECT 18,'WAS',9003,900301,254,5,'00:00',6,NULL
INSERT INTO #tmp SELECT 19,'WAS',9003,900301,254,6,'00:00',1,NULL
INSERT INTO #tmp SELECT 20,'WAS',9003,900301,254,6,'00:00',2,NULL
INSERT INTO #tmp SELECT 21,'WAS',9003,900301,254,6,'00:00',3,NULL
INSERT INTO #tmp SELECT 22,'WAS',9003,900301,254,6,'00:00',4,NULL
INSERT INTO #tmp SELECT 23,'WAS',9003,900301,254,7,'00:00',5,NULL
INSERT INTO #tmp SELECT 24,'WAS',9003,900301,254,7,'00:00',6,NULL
I have build one logic but that is time consuming.
DECLARE #Act INT, #iStart INT, #iMax INT, #iFirst INT
SET #iFirst = 7
SET #iMax = (SELECT MAX(ID) FROM #tmp)
SET #iStart = 1
WHILE(#iStart <= #iMax)
BEGIN
SET #Act = (SELECT Act FROM #tmp WHERE ID = #iStart)
IF(#iFirst > #Act )
BEGIN
UPDATE #tmp SET SequenceNo = #iStart WHERE ID = #iStart
END
SET #iFirst = #Act
SET #iStart = #iStart + 1
END
I am looking out for any alternative optimized solution.
Is this what you wanted?
update tupd
set
SequenceNo = tupd.ID
from (
select
*
, LAG(t.Act, 1, null) over(order by t.ID) as LagAct
from #tmp t
) tt
inner join #tmp tupd on tt.ID = tupd.ID
where tt.Act < tt.LagAct
select
*
from #tmp tt
order by tt.ID
You can find breaks in the Act sequence if you compare the current row with the previous. In current SQL Server versions, ie 2012+ you can do that with the LAG() method. In previous versions, you have to perform a self join on the current ID value and its previous value. If the difference between the current and previous Act values isn't 1, there is a break in the sequence. This only works if there are no gaps in ID.
This query will return 1 in the SeqBreak column for each row where Act restarts
select
t1.ID,
t1.SequenceNo ,
case when t1.act = t2.act+1 then '0' else '1' end as SeqBreak
from #tmp t1 left join #tmp t2 on t1.id=t2.id+1
You can use this in a CTE to select only the rows where Act breaks. You can update the CTE directly, at least in SQL Server 2014.
with x as (
select
t1.ID,
t1.SequenceNo ,
case when t1.act = t2.act+1 then '0' else '1' end as SeqBreak
from #tmp t1 left join #tmp t2 on t1.id=t2.id+1 )
update x
set SequenceNo=x.ID
where seqbreak=1 and id>1
If that doesn't work with SQL Server 2008, you'll have to join between the cte and the table:
with x as (
select
t1.ID,
t1.SequenceNo ,
case when t1.act = t2.act+1 then '0' else '1' end as SeqBreak
from #tmp t1 left join #tmp t2 on t1.id=t2.id+1 )
update #tmp
set SequenceNo=x.ID
from #tmp inner join x on x.ID=#tmp.ID
where seqbreak=1 and #tmp.id>1
The equivalent query using LAG(), one of the windowing functions in SQL Server 2012 is simpler and twice as fast, since it avoids the self join:
with x as (
select
ID,
SequenceNo ,
case when act = 1 +LAG(act,1) OVER (ORDER BY ID) then '0' else '1' end as SeqBreak
from #tmp)
update x
set SequenceNo=x.ID
where seqbreak=1 and id>1
;WITH CTE
AS
(
SELECT ID,Act,RANK() OVER (PARTITION BY [DayOfWeek] ORDER BY Act) RN
FROM #tmp
)
UPDATE t
SET t.SequenceNo = t.id
FROM #tmp t
inner join CTE C
ON t.ID = C.ID
WHERE C.RN = 1
If I'm getting your question correctly below query should fetch the desired result.
update t3 set sequenceno = t3.id
from
#temp t1
cross apply (select id+1 as idsum
from #temp
tmp where t1.id = tmp.id)t2
inner join #temp t3
on t3.id = t2.idsum
where t1.act>t3.act

How to find group of rows of a table that match in another table in SQL?

I have two tables in SQL Server,
Declare #Table1 Table ( TID1 INT, TP1 INT)
Declare #Table2 Table ( TID2 INT, TP2 INT)
INSERT INTO #Table1 (TID1,TP1) VALUES (100,1)
INSERT INTO #Table1 (TID1,TP1) VALUES (100,2)
INSERT INTO #Table1 (TID1,TP1) VALUES (100,3)
INSERT INTO #Table2 (TID2,TP2) VALUES (101,1)
INSERT INTO #Table2 (TID2,TP2) VALUES (101,2)
INSERT INTO #Table2 (TID2,TP2) VALUES (101,3)
INSERT INTO #Table2 (TID2,TP2) VALUES (102,1)
INSERT INTO #Table2 (TID2,TP2) VALUES (102,2)
INSERT INTO #Table2 (TID2,TP2) VALUES (103,1)
INSERT INTO #Table2 (TID2,TP2) VALUES (103,2)
INSERT INTO #Table2 (TID2,TP2) VALUES (103,3)
INSERT INTO #Table2 (TID2,TP2) VALUES (103,4)
INSERT INTO #Table2 (TID2,TP2) VALUES (104,2)
INSERT INTO #Table2 (TID2,TP2) VALUES (105,3)
Having Data as :
TID1 TP1
----------- -----------
100 1
100 2
100 3
TID2 TP2
----------- -----------
101 1
101 2
101 3
102 1
102 2
103 1
103 2
103 3
103 4
104 2
105 3
I want to select those records which having exact matching of TP1 column in Table2 TP2 column. EX TID2 having ID 101 will be only in result set
SELECT t2.TID2
FROM #Table2 t2
LEFT JOIN #Table1 t1
ON t2.TP2 = t1.TP1
GROUP BY t2.TID2
HAVING SUM(CASE WHEN t1.TP1 IS NULL THEN 1 ELSE 0 END) = 0 AND
COUNT(*) = (SELECT COUNT(*) FROM #Table1)
Try Like below.
SELECT TID2
FROM #TABLE1 T
RIGHT JOIN #TABLE2 T2
ON T.TP1 = T2.TP2
GROUP BY TID2
HAVING COUNT(T2.TP2) = (SELECT COUNT(*) FROM #TABLE1)
-- you can calculated this in CTEW or sub-query if you do not like to be in variable
DECLARE #MaxRowsCount INT = (SELECT COUNT(*) FROM #Table1);
SELECT T2.[TID2]
FROM #Table2 T2
LEFT JOIN #Table1 T1
ON T2.[TP2] = T1.[TP1]
GROUP BY T2.[TID2]
HAVING
(
-- current count of rows should be the same as the row count from the first table
COUNT(T2.[TP2]) = #MaxRowsCount
)

SQL Server: How to use UNION with two queries that BOTH have a WHERE clause?

Given:
Two queries that require filtering:
select top 2 t1.ID, t1.ReceivedDate
from Table t1
where t1.Type = 'TYPE_1'
order by t1.ReceivedDate desc
And:
select top 2 t2.ID
from Table t2
where t2.Type = 'TYPE_2'
order by t2.ReceivedDate desc
Separately, these return the IDs I'm looking for: (13, 11 and 12, 6)
Basically, I want the two most recent records for two specific types of data.
I want to union these two queries together like so:
select top 2 t1.ID, t2.ReceivedDate
from Table t1
where t1.Type = 'TYPE_1'
order by ReceivedDate desc
union
select top 2 t2.ID
from Table t2
where t2.Type = 'TYPE_2'
order by ReceivedDate desc
Problem:
The problem is that this query is invalid because the first select cannot have an order by clause if it is being unioned. And it cannot have top 2 without having order by.
How can I fix this situation?
You should be able to alias them and use as subqueries (part of the reason your first effort was invalid was because the first select had two columns (ID and ReceivedDate) but your second only had one (ID) - also, Type is a reserved word in SQL Server, and can't be used as you had it as a column name):
declare #Tbl1 table(ID int, ReceivedDate datetime, ItemType Varchar(10))
declare #Tbl2 table(ID int, ReceivedDate datetime, ItemType Varchar(10))
insert into #Tbl1 values(1, '20010101', 'Type_1')
insert into #Tbl1 values(2, '20010102', 'Type_1')
insert into #Tbl1 values(3, '20010103', 'Type_3')
insert into #Tbl2 values(10, '20010101', 'Type_2')
insert into #Tbl2 values(20, '20010102', 'Type_3')
insert into #Tbl2 values(30, '20010103', 'Type_2')
SELECT a.ID, a.ReceivedDate FROM
(select top 2 t1.ID, t1.ReceivedDate
from #tbl1 t1
where t1.ItemType = 'TYPE_1'
order by ReceivedDate desc
) a
union
SELECT b.ID, b.ReceivedDate FROM
(select top 2 t2.ID, t2.ReceivedDate
from #tbl2 t2
where t2.ItemType = 'TYPE_2'
order by t2.ReceivedDate desc
) b
select * from
(
select top 2 t1.ID, t1.ReceivedDate
from Table t1
where t1.Type = 'TYPE_1'
order by t1.ReceivedDate de
) t1
union
select * from
(
select top 2 t2.ID
from Table t2
where t2.Type = 'TYPE_2'
order by t2.ReceivedDate desc
) t2
or using CTE (SQL Server 2005+)
;with One as
(
select top 2 t1.ID, t1.ReceivedDate
from Table t1
where t1.Type = 'TYPE_1'
order by t1.ReceivedDate de
)
,Two as
(
select top 2 t2.ID
from Table t2
where t2.Type = 'TYPE_2'
order by t2.ReceivedDate desc
)
select * from One
union
select * from Two
declare #T1 table(ID int, ReceivedDate datetime, [type] varchar(10))
declare #T2 table(ID int, ReceivedDate datetime, [type] varchar(10))
insert into #T1 values(1, '20010101', '1')
insert into #T1 values(2, '20010102', '1')
insert into #T1 values(3, '20010103', '1')
insert into #T2 values(10, '20010101', '2')
insert into #T2 values(20, '20010102', '2')
insert into #T2 values(30, '20010103', '2')
;with cte1 as
(
select *,
row_number() over(order by ReceivedDate desc) as rn
from #T1
where [type] = '1'
),
cte2 as
(
select *,
row_number() over(order by ReceivedDate desc) as rn
from #T2
where [type] = '2'
)
select *
from cte1
where rn <= 2
union all
select *
from cte2
where rn <= 2
The basic premise of the question and the answers are wrong. Every Select in a union can have a where clause. It's the ORDER BY in the first query that's giving yo the error.
The answer is misleading because it attempts to fix a problem that is not a problem. You actually CAN have a WHERE CLAUSE in each segment of a UNION. You cannot have an ORDER BY except in the last segment. Therefore, this should work...
select top 2 t1.ID, t1.ReceivedDate
from Table t1
where t1.Type = 'TYPE_1'
-----remove this-- order by ReceivedDate desc
union
select top 2 t2.ID, t2.ReceivedDate --- add second column
from Table t2
where t2.Type = 'TYPE_2'
order by ReceivedDate desc
Create views on two first "selects" and "union" them.
Notice that each SELECT statement within the UNION must have the same number of columns. The columns must also have similar data types. Also, the columns in each SELECT statement must be in the same order.
you are selecting
t1.ID, t2.ReceivedDate
from Table t1
union
t2.ID
from Table t2
which is incorrect.
so you have to write
t1.ID, t1.ReceivedDate from Table t1
union
t2.ID, t2.ReceivedDate from Table t1
you can use sub query here
SELECT tbl1.ID, tbl1.ReceivedDate FROM
(select top 2 t1.ID, t1.ReceivedDate
from tbl1 t1
where t1.ItemType = 'TYPE_1'
order by ReceivedDate desc
) tbl1
union
SELECT tbl2.ID, tbl2.ReceivedDate FROM
(select top 2 t2.ID, t2.ReceivedDate
from tbl2 t2
where t2.ItemType = 'TYPE_2'
order by t2.ReceivedDate desc
) tbl2
so it will return only distinct values by default from both table.
select top 2 t1.ID, t2.ReceivedDate, 1 SortBy
from Table t1
where t1.Type = 'TYPE_1'
union
select top 2 t2.ID, 2 SortBy
from Table t2
where t2.Type = 'TYPE_2'
order by 3,2

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