Good evening everyone, I'm trying to do an update on a Table but I can't really make it work
The feature needed is:
-Watch a field on a form, it contains the number of people that need to sit at the restaurant table.
-Find the first free table that has enough seats, set it as busy and assign a random waiter
Any idea?
more db infos:
Table "Waiters" is composed by ID(Autonumber),Name(Short Text). Has 2 names atm
Table "Tables" is composed by ID(Autonumber),Seats(Number),Busy(y/n),Waiter(short text). All tables have a fixed number of seats and have no Waiter + not busy
SOLUTION:
In the end i used "First" for the assignment and it works perfectly as it follows:
UPDATE Tables SET Tables.Waiter = DLookUp("FirstName","TopWtr")
WHERE ID IN (SELECT FIRST (ID)
FROM Tables
WHERE Seats >= Val(Forms!Room!Text12) AND Waiter Is Null);
Top wasn't working because it was returning multiple records - every table with same number of seats - and couldn't make it work with DISTINCT. This works probably because the table is already ordered by seats
Thanks to June7 for the input
Cannot SET a field value to result of a SELECT subquery - SELECT returns a dataset not a single value. Can return a single value with domain aggregate function.
Build a query object named TopWtr:
SELECT Top 1 ID FROM Waiters ORDER BY Rnd(ID);
Then use DLookup to pull that value. The Busy field seems redundant because if table has a waiter assigned that would indicate busy.
UPDATE Tables SET Tables.Waiter = DLookUp("ID","TopWtr"), Tables.Busy = True
WHERE ID IN (SELECT TOP 1 ID FROM Tables
WHERE Seats >= Val(Forms!Room!Testo17) AND Waiter Is Null
ORDER BY Seats)
An INNER JOIN may be preferable to WHERE clause:
UPDATE Tables INNER JOIN (SELECT TOP 1 ID FROM Tables
WHERE Seats >= Val(Forms!Room!Testo17) AND Waiter Is Null
ORDER BY Seats) AS T1
ON Tables.ID = T1.ID
SET Tables.Waiter = DLookUp("ID","TopWtr"), Tables.Busy = True
Related
Amateur SQL writer here having a problem with building out table based on values from an existing one.
The MASTER table logs a record with an ID every time a service is used. ID remains the same per user, but will repeat to track relevant information during that usage. Table holds about 2m records and 20k DISTINCT IDs.
*Example -
USER ID | Used_Amount
USER_1998 | 9GB,
USER_1999 | 4GB,
USER_1999 | 1GB,
USER_1999 |0.5 GB*
Would like for the new table is create column that SUMS the usage and organizes based on DISTINCT ID.
Goal -
ID . TOTAL USAGE
USER_1998 - 9GB
USER_1999 - 5.5GB
Code below is my attempt...
UPDATE ml_draft
SET true_usage = (
SELECT SUM(true_usage)
FROM table2 t2
INNER JOIN ml_draft ON
ml_draft.subscription_id = t2.subscription_id);
Let me know if there are any additional details to add. Errors vary
You want a correlated subquery. So, there is no need to use JOIN in the subquery:
UPDATE ml_draft d
SET true_usage = (SELECT SUM(t2.true_usage)
FROM table2 t2
WHERE d.subscription_id = t2.subscription_id
);
For performance, you want an index on table2(subscription_id, true_usage).
There are two tables Table A and Table B. These contains the same columns cost and item. The Table B contains the list of items and their corresponding costs whereas the Table A contains only the list of items.
Now we need to check the items of Table A, if they are present in the Table B then the corresponging item cost should be assigned to the item's cost in Table A.
Can someone help me out by writing a query for this.
Consider the tables as shown:
Table A:
item cost
-------------
pen null
book null
watch null
Table B:
item cost
-------------
watch 1000
book 50
Expected output
Table A:
item cost
pen 0
book 50
watch 1000
Just add a foreign key (primary key of table A) in the Table B as you can say table A ID then add a join(right join may be) in the query to get or assign the prices respective items.
join be like
SELECT item, cost
FROM tablename a
RIGHT JOIN tablename b ON a.item= b.item;
Edit:
Just edit this table name ,now run it.
I would structure the update like this:
with cost_data as (
select
item,
max (cost) filter (where item = 'watch') as watch,
max (cost) filter (where item = 'book') as book
from table_b
group by item
)
update table_a a
set
watch = c.watch,
book = c.book
from cost_data c
where
a.item = c.item and
(a.watch is distinct from c.watch or
a.book is distinct from c.book)
In essence, I am doing a common table expression to do a poor man's pivot table on the Table B to get the rows into columns. One caveat here -- if there are multiple costs listed for the same item, this may not do what you want, but then you would need to know how to handle that in almost any case.
Then I am doing an "update A from B" against the CTE.
The last part is not critical, per se, but it is helpful -- to limit the query to only execute on rows that need to change. It's best to limit DML if it doesn't need to occur (the best way to optimize something is to not do it).
There are plenty of ways you could do this, if you are taking table b to be the one containing the price then a left outer join would do the trick.
SELECT
table_a.item,
CASE
WHEN table_b.cost IS NULL
THEN 0
ELSE table_b.cost
END as cost
FROM table_a
LEFT OUTER JOIN table_b ON table_a.item = table_b.item
The result also appears to suggest that pen which is not in table b should have a price of 0 (this is bad practice) but for the sake of returning the desired result you will want a case statement to assign a value if it is null.
In order to update the table, as per the comment
update table_a set cost = some_alias.cost
from (
SELECT
table_a.item,
CASE
WHEN table_b.cost IS NULL
THEN 0
ELSE table_b.cost
END as cost
FROM table_a
LEFT OUTER JOIN table_b ON table_a.item = table_b.item
) some_alias
where table_a.item = some_alias.item
I have one table named: ORDERS
this table contains OrderNumber's which belong to the same person and same address lines for that person.
However sometimes the data is inconsistent;
as example looking at the table screenshot: Orders table with bad data to fix -
you all can noticed that orderNumber 1 has a name associated to and addresses line1-2-3-4. sometimes those are all different by some character or even null.
my goal is to update all those 3 lines with one set of data that is already there and set equally all the 3 rows.
to make more clear the result expected should be like this:
enter image description here
i am currently using a MERGE statement to avoid a CURSOR (for loop )
but i am having problems to make it work
here the SQL
MERGE INTO ORDERS O USING
(SELECT
INNER.ORDERNUMBER,
INNER.NAME,
INNER.LINE1,
INNER.LINE2,
INNER.LINE3,
INNER.LINE4
FROM ORDERS INNER
) TEMP
ON( O.ORDERNUMBER = TEMP.ORDERNUMBER )
WHEN MATCHED THEN
UPDATE
SET
O.NAME = TEMP.NAME,
O.LINE1 = TEMP.LINE1,
O.LINE2 = TEMP.LINE2,
O.LINE3 = TEMP.LINE3,
O.LINE4 = TEMP.LINE4;
the biggest issues i am facing is to pick a single row out of the 3 randomly - it does not matter whihc of the data - row i pick to update the line/s
as long i make the records exaclty the same for an order number.
i also used ROWNUM =1 but it in multip[le updates will only output one row and update maybe thousand of lines with the same address and name whihch belong to an order number.
order number is the join column to use ...
kind regards
A simple correlated subquery in an update statement should work:
update orders t1
set (t1.name, t1.line1, t1.line2, t1.line3, t1.line4) =
(select t2.name, t2.line1, t2.line2, t2.line3, t2.line4
from orders t2
where t2.OrderNumber = t1.OrderNumber
and rownum < 2)
It is a little bit tricky for me so I need your help :)
I want to update the column Relevant to 0 WHERE Contract_Status_Code is 10 OR the Date_Contract_start YEAR is the same AND the Ranking_Value is lower than the other one ON all records that have the same VIN.
So I want to compare all records which have the same VIN.
Few examples to illustrate it:
I have there two records with the VIN = 123456. One of them (ID = 6847) has a higher Ranking_Value (7) than the other one (3). The YEAR is the same as well so I want to update the column relevant to 0 where the ID is 8105.
Two records with the VIN = 654321. Both of them have the same Ranking_Value but the record with the id = 11012 has the value 10 for the column Contract_Status_Code so I want to update the relevant column to 0 where the ID = 11012.
The last two records... They have the VIN = 171819. The first one (ID = 11578) has the higher Ranking_Value. But they have a different year where the contract has started. So I don't want to update both.
It is also possible that there are three or four records with the same VIN.
I hope you understand my problem. I'm from Germany so sorry for my English :)
By considering your ID column as unique or Identity column, I can suggest you the below query for your solution:
With cte
As
(Select a.Id, a.VIN From Table a
Join (Select max(Ranking_Value) ranks,VIN From Table Group By VIN, Year(Date_Contract_start)) b
on a.VIN=b.VIN And a.Ranking_Value = b.ranks)
update table
set Relevant = 0
where (Contract_Status_Code = 10) Or
ID Not In (Select id from cte)
update table1
set Relevant = 0
where Contract_Status_Code = 10
or (VIN,Year,Ranking_value) not in(
select VIN,Year,max(Ranking_Value)
from table1
group by VIN,Year
)
2 records in above image are from Db, in above table Constraint are (SID and LINE_ITEM_ID),
SID and LINE_ITEM_ID both column are used to find a unique record.
My issues :
I am looking for a query it should fetch the recored from DB depending on conditions
if i search for PART_NUMBER = 'PAU43-IMB-P6'
1. it should fetch one record from DB if search for PART_NUMBER = 'PAU43-IMB-P6', no mater to which SID that item belong to if there is only one recored either under SID =1 or SID = 2.
2. it should fetch one record which is under SID = 2 only, from DB on search for PART_NUMBER = 'PAU43-IMB-P6', if there are 2 items one in SID=1 and other in SID=2.
i am looking for a query which will search for a given part_number depending on Both SID 1 and 2, and it should return value under SID =2 and it can return value under SID=1 only if the there are no records under SID=2 (query has to withstand a load of Million record search).
Thank you
Select *
from Table
where SID||LINE_ITEM_ID = (
select Max(SID)||Max(LINE_ITEM_ID)
from table
where PART_NUMBER = 'PAU43-IMB-P6'
);
If I understand correctly, for each considered LINE_ITEM_ID you want to return only the one with the largest value for SID. This is a common requirement and, as with most things in SQL, can be written in many different ways; the best performing will depend on many factors, not least of which is the SQL product you are using.
Here's one possible approach:
SELECT DISTINCT * -- use a column list
FROM YourTable AS T1
INNER JOIN (
SELECT T2.LINE_ITEM_ID,
MAX(T2.SID) AS max_SID
FROM YourTable AS T2
GROUP
BY T2.LINE_ITEM_ID
) AS DT1 (LINE_ITEM_ID, max_SID)
ON T1.LINE_ITEM_ID = DT1.LINE_ITEM_ID
AND T1.SID = DT1.max_SID;
That said, I don't recall seeing one that relies on the UNION relational operator. You could easily rewrite the above using the INTERSECT relational operator but it would be more verbose.
Well in my case it worked something like this:
select LINE_ITEM_ID,SID,price_1,part_number from (
(select LINE_ITEM_ID,SID,price_1,part_number from Table where SID = 2)
UNION
(select LINE_ITEM_ID,SID,price_1,part_number from Table SID = 1 and line_item_id NOT IN (select LINE_ITEM_ID,SID,price_1,part_number from Table SID = 2)))
This query solved my issue..........