I'd like to insert a record using values from different tables
just to illustrate:
INSERT INTO tbl1
VALUES([value1], [value2], NOW())
value1 is a number that comes from a cell in a random row in a different table
value2 is another number that comes from a cell in a random row in another table
Here's how I'm trying to do it:
INSERT INTO transactions(itemid, userid, tdate)
VALUES((SELECT TOP 1 ID FROM items ORDER BY RND(ID)), (SELECT TOP 1 ID FROM users ORDER BY RND(ID)), (NOW()))
But this throws an error:
Query input must contain at least one table or query
Any help would be greatly appreciated.
Thanks!
You could rewrite your statement to use a SELECT instead of VALUES:
INSERT INTO transactions(itemid, userid, tdate)
SELECT TOP 1 items.ID, users.ID, NOW()
FROM items, users
ORDER BY Rnd(-(1000*items.ID*users.ID)*Time()),
items.ID, users.ID
Edit: I added the ORDER BY clause which will lead to more random sort orders. The negative value will ensure a sort of randomize. See also this question.
Edit2: extended ORDER BY clause to ensure TOP 1 will not have to deal with ties.
Related
I have a table like this
CREATE TABLE userinteractions
(
userid bigint,
dobyr int,
-- lots more fields that are not relevant to the question
);
My problem is that some of the data is polluted with multiple dobyr values for the same user.
The table is used as the basis for further processing by creating a new table. These cases need to be removed from the pipeline.
I want to be able to create a clean table that contains unique userid and dobyr limited to the cases where there is only one value of dobyr for the userid in userinteractions.
For example I start with data like this:
userid,dobyr
1,1995
1,1995
2,1999
3,1990 # dobyr values not equal
3,1999 # dobyr values not equal
4,1989
4,1989
And I want to select from this to get a table like this:
userid,dobyr
1,1995
2,1999
4,1989
Is there an elegant, efficient way to get this in a single sql query?
I am using postgres.
EDIT: I do not have permissions to modify the userinteractions table, so I need a SELECT solution, not a DELETE solution.
Clarified requirements: your aim is to generate a new, cleaned-up version of an existing table, and the clean-up means:
If there are many rows with the same userid value but also the same dobyr value, one of them is kept (doesn't matter which one), rest gets discarded.
All rows for a given userid are discarded if it occurs with different dobyr values.
create table userinteractions_clean as
select distinct on (userid,dobyr) *
from userinteractions
where userid in (
select userid
from userinteractions
group by userid
having count(distinct dobyr)=1 )
order by userid,dobyr;
This could also be done with an not in, not exists or exists conditions. Also, select which combination to keep by adding columns at the end of order by.
Updated demo with tests and more rows.
If you don't need the other columns in the table, only something you'll later use as a filter/whitelist, plain userid's from records with (userid,dobyr) pairs matching your criteria are enough, as they already uniquely identify those records:
create table userinteractions_whitelist as
select userid
from userinteractions
group by userid
having count(distinct dobyr)=1
Just use a HAVING clause to assert that all rows in a group must have the same dobyr.
SELECT
userid,
MAX(dobyr) AS dobyr
FROM
userinteractions
GROUP BY
userid
HAVING
COUNT(DISTINCT dobyr) = 1
I have three joined tables Student, StudentTransportOrder and Transport in SQL Server 2012.
I have created a StudentActivity view for this.
In the StudentTransportOrder table, each student record has a unique TransportOrderID.
When transport is ordered, VehicleID this is recorded into the StudentTransportOrder table.
Unfortunately the same VehicleID has been entered for the same date and time for a student records.
The StudentActivity view already returns records based on where conditions, but I also need to remove the duplicate records, preferably keep the records where if a student has used transport on the same date and time, that only one distinct VehicleID is returned and preferably the where the transport type is TransportVehicle = Car
How can I amend the view , without deleting records from the main tables, also bring back records even if no transport has been ordered
Please help
Append
ROW_NUMBER() OVER(PARTITION BY StudentID,VehicleID ORDER BY (SELECT NULL)) AS PartitionedCount
... to your query and use a filter like WHERE PartitionedCount=1.
This will number your rows for each combination of Student and vehicle separately (you'll have to include the date or datetime probably).
You can use the (ORDER BY (SELECT NULL)) to force a car sorted on top...
UPDATE
As I do not know your actual tables here's a general example:
DECLARE #tbl TABLE(ID INT IDENTITY,GroupID INT,SomeValue VARCHAR(100));
INSERT INTO #tbl(GroupID,SomeValue) VALUES
(1,'val 1 for 1')
,(1,'val 2 for 1')
,(1,'val 3 for 1')
,(2,'val 1 for 2')
,(2,'val 2 for 2')
,(3,'val 1 for 3')
,(3,'val 2 for 3');
WITH Numbered AS
(
SELECT tbl.*
,ROW_NUMBER() OVER(PARTITION BY GroupID ORDER BY ID /*DESC*/) AS Number
FROM #tbl AS tbl
)
SELECT * FROM Numbered
WHERE Number=1
Try first without the WHERE. You will get all rows with partitioned numbering. Using the WHERE will reduce the output to the one with number =1.
It is on you to find a clever ORDER BY which brings your cars to the top (CASE will help you probably).
Just good to know: In my ORDER BY you find an inactive DESC. If you take away the /**/ you can use the same approach to find the last row to a given sort order.
I would like to see a most concise way to do what is outlined in this SO question: Sum values from multiple rows into one row
that is, combine multiple rows while summing a column.
But how to then delete the duplicates. In other words I have data like this:
Person Value
--------------
1 10
1 20
2 15
And I want to sum the values for any duplicates (on the Person col) into a single row and get rid of the other duplicates on the Person value. So my output would be:
Person Value
-------------
1 30
2 15
And I would like to do this without using a temp table. I think that I'll need to use OVER PARTITION BY but just not sure. Just trying to challenge myself in not doing it the temp table way. Working with SQL Server 2008 R2
Simply put, give me a concise stmt getting from my input to my output in the same table. So if my table name is People if I do a select * from People on it before the operation that I am asking in this question I get the first set above and then when I do a select * from People after the operation, I get the second set of data above.
Not sure why not using Temp table but here's one way to avoid it (tho imho this is an overkill):
UPDATE MyTable SET VALUE = (SELECT SUM(Value) FROM MyTable MT WHERE MT.Person = MyTable.Person);
WITH DUP_TABLE AS
(SELECT ROW_NUMBER()
OVER (PARTITION BY Person ORDER BY Person) As ROW_NO
FROM MyTable)
DELETE FROM DUP_TABLE WHERE ROW_NO > 1;
First query updates every duplicate person to the summary value. Second query removes duplicate persons.
Demo: http://sqlfiddle.com/#!3/db7aa/11
All you're asking for is a simple SUM() aggregate function and a GROUP BY
SELECT Person, SUM(Value)
FROM myTable
GROUP BY Person
The SUM() by itself would sum up the values in a column, but when you add a secondary column and GROUP BY it, SQL will show distinct values from the secondary column and perform the aggregate function by those distinct categories.
i have loanTable that contain two field loan_id and status
loan_id status
==============
1 0
2 9
1 6
5 3
4 5
1 4 <-- How do I select this??
4 6
In this Situation i need to show the last Status of loan_id 1 i.e is status 4. Can please help me in this query.
Since the 'last' row for ID 1 is neither the minimum nor the maximum, you are living in a state of mild confusion. Rows in a table have no order. So, you should be providing another column, possibly the date/time when each row is inserted, to provide the sequencing of the data. Another option could be a separate, automatically incremented column which records the sequence in which the rows are inserted. Then the query can be written.
If the extra column is called status_id, then you could write:
SELECT L1.*
FROM LoanTable AS L1
WHERE L1.Status_ID = (SELECT MAX(Status_ID)
FROM LoanTable AS L2
WHERE L2.Loan_ID = 1);
(The table aliases L1 and L2 could be omitted without confusing the DBMS or experienced SQL programmers.)
As it stands, there is no reliable way of knowing which is the last row, so your query is unanswerable.
Does your table happen to have a primary id or a timestamp? If not then what you want is not really possible.
If yes then:
SELECT TOP 1 status
FROM loanTable
WHERE loan_id = 1
ORDER BY primaryId DESC
-- or
-- ORDER BY yourTimestamp DESC
I assume that with "last status" you mean the record that was inserted most recently? AFAIK there is no way to make such a query unless you add timestamp into your table where you store the date and time when the record was added. RDBMS don't keep any internal order of the records.
But if last = last inserted, that's not possible for current schema, until a PK addition:
select top 1 status, loan_id
from loanTable
where loan_id = 1
order by id desc -- PK
Use a data reader. When it exits the while loop it will be on the last row. As the other posters stated unless you put a sort on the query, the row order could change. Even if there is a clustered index on the table it might not return the rows in that order (without a sort on the clustered index).
SqlDataReader rdr = SQLcmd.ExecuteReader();
while (rdr.Read())
{
}
string lastVal = rdr[0].ToString()
rdr.Close();
You could also use a ROW_NUMBER() but that requires a sort and you cannot use ROW_NUMBER() directly in the Where. But you can fool it by creating a derived table. The rdr solution above is faster.
In oracle database this is very simple.
select * from (select * from loanTable order by rownum desc) where rownum=1
Hi if this has not been solved yet.
To get the last record for any field from a table the easiest way would be to add an ID to each record say pID. Also say that in your table you would like to hhet the last record for each 'Name', run the simple query
SELECT Name, MAX(pID) as LastID
INTO [TableName]
FROM [YourTableName]
GROUP BY [Name]/[Any other field you would like your last records to appear by]
You should now have a table containing the Names in one column and the last available ID for that Name.
Now you can use a join to get the other details from your primary table, say this is some price or date then run the following:
SELECT a.*,b.Price/b.date/b.[Whatever other field you want]
FROM [TableName] a LEFT JOIN [YourTableName]
ON a.Name = b.Name and a.LastID = b.pID
This should then give you the last records for each Name, for the first record run the same queries as above just replace the Max by Min above.
This should be easy to follow and should run quicker as well
If you don't have any identifying columns you could use to get the insert order. You can always do it like this. But it's hacky, and not very pretty.
select
t.row1,
t.row2,
ROW_NUMBER() OVER (ORDER BY t.[count]) AS rownum from (
select
tab.row1,
tab.row2,
1 as [count]
from table tab) t
So basically you get the 'natural order' if you can call it that, and add some column with all the same data. This can be used to sort by the 'natural order', giving you an opportunity to place a row number column on the next query.
Personally, if the system you are using hasn't got a time stamp/identity column, and the current users are using the 'natural order', I would quickly add a column and use this query to create some sort of time stamp/incremental key. Rather than risking having some automation mechanism change the 'natural order', breaking the data needed.
I think this code may help you:
WITH cte_Loans
AS
(
SELECT LoanID
,[Status]
,ROW_NUMBER() OVER(ORDER BY (SELECT 1)) AS RN
FROM LoanTable
)
SELECT LoanID
,[Status]
FROM LoanTable L1
WHERE RN = ( SELECT max(RN)
FROM LoanTable L2
WHERE L2.LoanID = L1.LoanID)
I have a status table, and another table containing additional data. My object IDs are the PK in the status table, so I need to insert those into the additional data table for each new row.
I need to insert a new row into my statusTable for each new listing, containing just constants.
declare #temp TABLE(listingID int)
insert into statusTable(status, date)
output Inserted.listingID into #temp
select 1, getdate()
from anotherImportedTable
This gets me enough new listing IDs to use.
I now need to insert the actual listing data into another table, and map each row to one of those listingIDs -
insert into listingExtraData(listingID, data)
select t.listingID, a.data
from #temp t, anotherImportedTable a
Now this obviously doesn't work, because otherDataTable and the IDs in #temp are unrelated... so I get far too many rows inserted.
How can I insert each row from anotherImportedTable into listingExtraData along with a unique newly created listingID? could I possibly trigger some more sql at the point I do the output in the first block of sql?
edit: thanks for the input so far, here's what the tables look like:
anotherImportedTable:
data
statusTable:
listingID (pk), status, date
listingExtraData:
data, listingID
You see that I only want to create one entry into statusTable per row in anotherImportedTable, then put one listingID with a row from anotherImportedTable into listingExtraData... I'm thinking that I might have to resort to a cursor perhaps?
Ok, here's how you can do it (if I'm right about what you actually want to do):
insert into listingExtraData(listingID, data)
select q1.listingID, q2.data
from
(select ListingID, ROW_NUMBER() OVER (order by ListingID) as rn from #temp t) as q1
inner join (select data, ROW_NUMBER() over (order by data) as rn from anotherImportedTable) q2 on q1.rn = q2.rn
In case you matching logic differs you will need to change sorting of anotherImportedTable. In case your match order can not be achieved by ordering anotherImportTable [in one way or another] then you're out of luck.