I have to select player name, Captain name from below mentioned table structure.
table structure are as follows.
create table #temp (Playerid int, PlayerName varchar (100), CaptainId int)
PlayerId PlayerName CaptainId
--------------------------------------
1 Dhoni NULL
2 Sachin 1
3 Rahul 1
I have to select player name along with his captain name from this table.
Can anybody
there are various ways to get answer of this queries like:
select playerName, (select t2.playername from #temp t2 where t2.playerid = t.captainid ) from #temp t
select t1.playername , t2.playername captain from #temp t1 left join #temp t2 on t1.captainid = t2.playerid
Assuming the CaptainId references the PlayerId on the same table, you would want the following:
select t.PlayerName, t2.PlayerName as CaptainName
from #temp t
left join #temp t2 on t.CaptainId = t2.PlayerId
If you wanted to exclude players with no captain, you would make it an inner join.
You could convert the null, of course:
select t.PlayerName, isnull(t2.PlayerName,'None') as CaptainName
from #temp t
left join #temp t2 on t.CaptainId = t2.PlayerId
You can use a self join and table aliases.
Something like
SELECT p.PlayerName,
c.PlayerName CaptainName
FROM #temp p LEFT JOIN
#temp c ON p.CaptainId = c.PlayerId
SELECT PlayerName, CaptainName
FROM PlayerTable INNER JOIN CaptainTable
ON PlayerTable.CaptainID=CaptainTable.CaptainID
WHERE CaptainName = 'your query'
Related
Query below works as planned, it shows exactly the way i joined it, and that is fine, but problem with it, is that if you have more "specialization" tables for users, something like "Mail type" or anything that user can have more then one data ... you would have to go two left joins for each and "give priority" via ISNULL (in this case)
I am wondering, how could I avoid using two joins and "give" priority to TypeId 2 over TypeId 1 in a single join, is that even possible?
if object_id('tempdb..#Tab1') is not null drop table #Tab1
create table #Tab1 (UserId int, TypeId int)
if object_id('tempdb..#Tab2') is not null drop table #Tab2
create table #Tab2 (TypeId int, TypeDescription nvarchar(50))
insert into #Tab1 (UserId, TypeId)
values
(1, 1),
(1, 2)
insert into #Tab2 (TypeId, TypeDescription)
values
(1, 'User'),
(2, 'Admin')
select *, ISNULL(t2.TypeDescription, t3.TypeDescription) [Role]
from #Tab1 t1
LEFT JOIN #Tab2 t2 on t1.TypeId = t2.TypeId and
t2.TypeId = 2
LEFT JOIN #Tab2 t3 on t1.TypeId = t3.TypeId and
t3.TypeId = 1
The first problem is determining priority. In this case, you could use the largest TypeId, but that does not seem like a great idea. You could add another column to serve as a priority ordinal instead.
From there, it is a top 1 per group query:
using top with ties and row_number():
select top 1 with ties
t1.UserId, t1.TypeId, t2.TypeDescription
from #Tab1 t1
left join #Tab2 t2
on t1.TypeId = t2.TypeId
order by row_number() over (
partition by t1.UserId
order by t2.Ordinal
--order by t1.TypeId desc
)
using common table expression and row_number():
;with cte as (
select t1.UserId, t1.TypeId, t2.TypeDescription
, rn = row_number() over (
partition by t1.UserId
order by t2.Ordinal
--order by t1.TypeId desc
)
from #Tab1 t1
left join #Tab2 t2
on t1.TypeId = t2.TypeId
)
select UserId, TypeId, TypeDescription
from cte
where rn = 1
rextester demo for both: http://rextester.com/KQAV36173
both return:
+--------+--------+-----------------+
| UserId | TypeId | TypeDescription |
+--------+--------+-----------------+
| 1 | 2 | Admin |
+--------+--------+-----------------+
Actually I don't think you don't need a join at all. But you have to take the max TypeID without respect to the TypeDescription, since these differences can defeat a Group By. So a workaround is to take the Max without TypeDescription initially, then subquery the result to get the TypeDescription.
SELECT dT.*
,(SELECT TypeDescription FROM #Tab2 T2 WHERE T2.TypeId = dT.TypeId) [Role] --2. Subqueries TypeDescription using the Max TypeID
FROM (
select t1.UserId
,MAX(T1.TypeId) [TypeId]
--, T1.TypeDescription AS [Role] --1. differences will defeat group by. Subquery for value later in receiving query.
from #Tab1 t1
GROUP BY t1.UserId
) AS dT
Produces Output:
UserId TypeId Role
1 2 Admin
Perhaps quite a simple question, that seems to have a rather complicated answer that I have not been able to dig out.
Im using an SQL-server 2012.
I have these two statements, that selects all my data based on a parameter, and then also selects up to five rows of data (which means no joins) from another table based on the IDs gotten from the first select.
SELECT * FROM TBL1 WHERE XXX
SELECT * FROM TBL2
WHERE TBL1_ID IN (SELECT ID FROM TBL1 WHERE XXX)
It seems very redundant to me, that I basicly have to repeat my TBL1 select in my TBL2, and instead I would like to know if I can select from TBL2 using the ID's from the * data I got from TBL1.
I am fully aware that this will most likely result in two resultsets that dont necessarily correlate, but I can generally use PHP array-manipulation to fix this so its not that big of a deal.
You also use EXISTS
SELECT * FROM TBL2
WHERE EXISTS (SELECT 1 FROM TBL1 WHERE TBL1.ID = TBL2.TBL1_ID AND XXX)
Using IN:
Declare #T1 table (ID INT , Value VARCHAR(50) );
Declare #T2 table (ID INT);
INSERT INTO #T1 Values (1,'First') , (2,'Second');
INSERT INTO #T2 Values (1),(3);
SELECT * FROM #T1 WHERE ID IN (SELECT ID FROM #T2);
Resault :
ID Value
----------- ------------------------------------------------------------------------------
1 First
Using INNER JOIN :
SELECT T1.ID , T1.Value FROM #T1 T1 INNER JOIN #T2 T2 ON T1.ID = T2.ID;
Resault:
ID Value
----------- ------------------------------------------------------------------------------
1 First
Using LEFT JOIN :
SELECT T1.ID , T1.Value FROM #T1 T1 LEFT JOIN #T2 T2 ON T1.ID = T2.ID
WHERE T2.ID IS NOT NULL;
Resault :
ID Value
----------- -------------------------------------------------------------------------------
1 First
I have a query setup below, and I'm having trouble with the recursion piece. I start with a contract(s), Abc and Xyz from Table1. I take Table1.Id, groupNo and look them up in Table2, to get the contracts(s) there, then look those contracts back up in Table1, repeating the process until it eventually returns null, and capturing the last iteration. Is CTE the way to handle this? If so, could someone help with the last iteration. I tried nesting, and haven't got it to work.
Table Structure
create table Table1 (id int, groupNo int, contract varchar(3))
insert into Table1 values(33,2,'Abc')
insert into Table1 values(34,8,'Xyz')
insert into Table1 values(88,11,'123')
insert into Table1 values(89,11,'456')
create table Table2 (id int, groupNo int, contract varchar(3))
insert into Table2 values(34,8,'123')
insert into Table2 values(34,8,'456')
insert into Table2 values(89,11,'789')
Query
with myCTE (id,groupNo,contract) as
(
select
t1.id
,t1.groupNo
,t2.contract
from Table1 t1
inner join Table2 t2 on t1.id = t2.id and t1.groupNo = t2.groupNo
union all
select
t1.id
,t1.groupNo
,c2.contract
from myCTE c2
inner join Table1 t1 on c2.contract = t1.contract
)
select top 10 id, groupNo, contract
from myCTE
SQL FIDDLE
This is one way of doing it.
Basically, I record the level of each recursion and only keep the highest level. See SQL Fiddle and query below:
declare #Table1 table(id int, groupNo int, contract varchar(3));
insert into #Table1 values(33,2,'Abc');
insert into #Table1 values(34,8,'Xyz');
insert into #Table1 values(88,11,'123');
insert into #Table1 values(89,11,'456');
declare #Table2 table(id int, groupNo int, contract varchar(3));
insert into #Table2 values(34,8,'123');
insert into #Table2 values(34,8,'456');
insert into #Table2 values(89,11,'789');
with myCTE (level, id, groupNo, contract, subcontract) as
(
select 0, t1.id,t1.groupNo, t1.contract
,t2.contract
from #Table1 t1
inner join #Table2 t2 on t1.id = t2.id and t1.groupNo = t2.groupNo
union all
select level+1, c2.id, c2.groupNo, c2.contract
,t2.contract
from myCTE c2
inner join #Table1 t1 on c2.subcontract = t1.contract
inner join #Table2 t2 on t1.id = t2.id and t1.groupNo = t2.groupNo
)
Select c.* From myCTE as c
Inner join (select id, groupNo, contract, level = max(level) From myCTE Group by id, groupNo, contract) as m
On m.level = c.level and m.id = c.id and m.groupNo = c.groupNo and m.contract = c.contract
OPTION (MAXRECURSION 0);
I also added table2 to the second select. You want it to behave like the first one and it needs to get the subcontract name from table2.
I have two tables with identical definition.
T1:
Name VARCHAR(50)
Qty INT
T2:
Name VARCHAR(50)
Qty INT
This is the data each table has:
T1:
Name Qty
a 1
b 2
c 3
d 4
T2:
Name Qty
a 1
b 3
e 5
f 10
I want to have result which can sum the Qty from both the tables based on Name.
Expected resultset:
Name TotalQty
a 2
b 5
c 3
d 4
e 5
f 10
If am do Left Join or Right Join, it is not going to return me the Name from either of the tables.
What i am thinking is to create a temp table and add these records and just do a SUM aggregate on Qty column but i think there should be a better way to do this.
This is how my query looks like which does not return the expected resultset:
SELECT t1.Name, ISNULL(SUM(t1.Qty + t2.Qty),0) TotalQty
FROM t1
LEFT JOIN t2
ON t1.Name = T2.Name
GROUP BY t1.Name
Can someone please tell me if creating a temp table is OK here or there is a better way to do this?
You can use a full outer join:
SELECT
ISNULL(t1.Name, t2.Name) AS Name,
ISNULL(t1.Qty, 0) + ISNULL(t2.Qty, 0) AS TotalQty
FROM t1
FULL JOIN t2 ON t1.Name = T2.Name
See it working online: sqlfiddle
You can use a UNION ALL to select both tables as one, since they have the same definition. From there, you can nest them as a derived table, and then SUM on that:
SELECT [Name], SUM(Qty) AS TotalQty
FROM (
SELECT [Name], Qty
FROM t1
UNION ALL
SELECT [Name], Qty
FROM t2
) YourDerivedTable
GROUP BY [Name]
I've got two tables:
TableA
------
ID,
Name
TableB
------
ID,
SomeColumn,
TableA_ID (FK for TableA)
The relationship is one row of TableA - many of TableB.
Now, I want to see a result like this:
ID Name SomeColumn
1. ABC X, Y, Z (these are three different rows)
2. MNO R, S
This won't work (multiple results in a subquery):
SELECT ID,
Name,
(SELECT SomeColumn FROM TableB WHERE F_ID=TableA.ID)
FROM TableA
This is a trivial problem if I do the processing on the client side. But this will mean I will have to run X queries on every page, where X is the number of results of TableA.
Note that I can't simply do a GROUP BY or something similar, as it will return multiple results for rows of TableA.
I'm not sure if a UDF, utilizing COALESCE or something similar might work?
Even this will serve the purpose
Sample data
declare #t table(id int, name varchar(20),somecolumn varchar(MAX))
insert into #t
select 1,'ABC','X' union all
select 1,'ABC','Y' union all
select 1,'ABC','Z' union all
select 2,'MNO','R' union all
select 2,'MNO','S'
Query:
SELECT ID,Name,
STUFF((SELECT ',' + CAST(T2.SomeColumn AS VARCHAR(MAX))
FROM #T T2 WHERE T1.id = T2.id AND T1.name = T2.name
FOR XML PATH('')),1,1,'') SOMECOLUMN
FROM #T T1
GROUP BY id,Name
Output:
ID Name SomeColumn
1 ABC X,Y,Z
2 MNO R,S
1. Create the UDF:
CREATE FUNCTION CombineValues
(
#FK_ID INT -- The foreign key from TableA which is used
-- to fetch corresponding records
)
RETURNS VARCHAR(8000)
AS
BEGIN
DECLARE #SomeColumnList VARCHAR(8000);
SELECT #SomeColumnList =
COALESCE(#SomeColumnList + ', ', '') + CAST(SomeColumn AS varchar(20))
FROM TableB C
WHERE C.FK_ID = #FK_ID;
RETURN
(
SELECT #SomeColumnList
)
END
2. Use in subquery:
SELECT ID, Name, dbo.CombineValues(FK_ID) FROM TableA
3. If you are using stored procedure you can do like this:
CREATE PROCEDURE GetCombinedValues
#FK_ID int
As
BEGIN
DECLARE #SomeColumnList VARCHAR(800)
SELECT #SomeColumnList =
COALESCE(#SomeColumnList + ', ', '') + CAST(SomeColumn AS varchar(20))
FROM TableB
WHERE FK_ID = #FK_ID
Select *, #SomeColumnList as SelectedIds
FROM
TableA
WHERE
FK_ID = #FK_ID
END
In MySQL there is a group_concat function that will return what you're asking for.
SELECT TableA.ID, TableA.Name, group_concat(TableB.SomeColumn)
as SomColumnGroup FROM TableA LEFT JOIN TableB ON
TableB.TableA_ID = TableA.ID
I think you are on the right track with COALESCE. See here for an example of building a comma-delimited string:
http://www.sqlteam.com/article/using-coalesce-to-build-comma-delimited-string
You may need to provide some more details for a more precise response.
Since your dataset seems kind of narrow, you might consider just using a row per result and performing the post-processing at the client.
So if you are really looking to make the server do the work return a result set like
ID Name SomeColumn
1 ABC X
1 ABC Y
1 ABC Z
2 MNO R
2 MNO S
which of course is a simple INNER JOIN on ID
Once you have the resultset back at the client, maintain a variable called CurrentName and use that as a trigger when to stop collecting SomeColumn into the useful thing you want it to do.
Assuming you only have WHERE clauses on table A create a stored procedure thus:
SELECT Id, Name From tableA WHERE ...
SELECT tableA.Id AS ParentId, Somecolumn
FROM tableA INNER JOIN tableB on TableA.Id = TableB.F_Id
WHERE ...
Then fill a DataSet ds with it. Then
ds.Relations.Add("foo", ds.Tables[0].Columns("Id"), ds.Tables[1].Columns("ParentId"));
Finally you can add a repeater in the page that puts the commas for every line
<asp:DataList ID="Subcategories" DataKeyField="ParentCatId"
DataSource='<%# Container.DataItem.CreateChildView("foo") %>' RepeatColumns="1"
RepeatDirection="Horizontal" ItemStyle-HorizontalAlign="left" ItemStyle-VerticalAlign="top"
runat="server" >
In this way you will do it client side but with only one query, passing minimal data between database and frontend
I tried the solution priyanka.sarkar mentioned and the didn't quite get it working as the OP asked. Here's the solution I ended up with:
SELECT ID,
SUBSTRING((
SELECT ',' + T2.SomeColumn
FROM #T T2
WHERE WHERE T1.id = T2.id
FOR XML PATH('')), 2, 1000000)
FROM #T T1
GROUP BY ID
Solution below:
SELECT GROUP_CONCAT(field_attr_best_weekday_value)as RAVI
FROM content_field_attr_best_weekday LEFT JOIN content_type_attraction
on content_field_attr_best_weekday.nid = content_type_attraction.nid
GROUP BY content_field_attr_best_weekday.nid
Use this, you also can change the Joins
SELECT t.ID,
t.NAME,
(SELECT t1.SOMECOLUMN
FROM TABLEB t1
WHERE t1.F_ID = T.TABLEA.ID)
FROM TABLEA t;
This will work for selecting from different table using sub query.
I have reviewed all the answers. I think in database insertion should be like:
ID Name SomeColumn
1. ABC ,X,Y Z (these are three different rows)
2. MNO ,R,S
The comma should be at previous end and do searching by like %,X,%