I am trying to make a mongoose query that modify two records at once but with different updated value.
Scenario: Increase User A's balance while decrease User B's balance.
Any idea???
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I would like to ask a question on how to correctly display single or multiple transactions if a user has more than one purchase from different stores in day. If a user bought once it will display "single" and if the user bought more than once it will display "multiple"
For reference, column F is for determining if the user bought more than once, 0= first transaction and 1= other transactions. If a user has only 0 and no 1s then it is considered single transaction only. I tried using this formula in column H:
=IF(COUNTIF(A$2:A2,A2)=1,
IF(COUNTIFS(A$2:A2,A2,D$2:D2,D2)>1,
OFFSET(A$2,MATCH(A2&D2,$A$2:A2&A2&$D$2:D2,0)-1,1),
MAX(IF($A1:A$2=A2,$F1:F$2))+1))
but, it was not showing the result I want.
If I understand your question correctly, it should be possible to use SUMPRODUCT to accomplish this.
Try: =IF(SUMPRODUCT(--(A:A=A2),--(D:D=D2))>1,"mutiple","single")
How can we do relational update queries in mongodb.
We have the following scenario:
In a bank the deposits of the clients are managed, once a certain
period of time is fulfilled the bank returns the deposit to the
clients plus the accrued interest, a client can have several deposits.
we create the client's collection, with his name, and what he has
available to withdraw, we create the deposit collection, with the
amount, the interest rate, and we join it to the client's model by the
client's id from a clientId field. Every 24 hours the bank updates all
user accounts, if the deposit creation date is less than two years,
the user's interest is updated, if the date is equal to 2 years a new
field is added to the deposit (expired: true), and to the client's
collection in the available field is added, what was already
accumulated, the interest, plus the amount of the deposit. To give a
solution I have tried to obtain all the deposits, I save them in an
object and I go through it with the map property. Inside the map I try
to update the clients that have expired deposits, however, only the
last element that runs through the map is being updated.
What would be the best solution to this problem. I clarify that I am using mongoose and nodejs.
Suppose that,I have a product collection named productCollection.How can i get all those products where the product's amount is less than a specific amount?What is the query
Imagine situation when a client has feed of objects with limit 10.
When the next 10 are required it sends request with skip 10 and limit 10.
But what if there are some new objects were added (or deleted) to collection since the 1st request with offset == 0.
Then on 2nd request (with offset == 10) response may have wrong objects order.
Sorting on time of their creation does not work here, because I have some feeds which are formed on sorting via some numeric field.
You can add a time field like created_at or updated_at. It must updated when ever the document is created or modified and the field must be unique.
Then query the DB for the range of time using $gte and $lte along with a sort on this time field.
This ensures that any changes made outside the time window will not get reflected in the pagination, provided that the time field does not have duplicates. Most probably if you include microtime, duplicates wont happen.
It really depends on what you want the result to be.
If you want the original objects in their original order regardless of Delete and Add operations then you need to make a copy of the list (or at least of the order) and then page through that. Copy every Id to a new collection that doesn't change once the page has loaded and then paginate through that.
Alternatively, and perhaps more likely, what you want is to see the next 10 after the last one in the current set including any Delete or Add operations that have take place since. For this, you can use the sorted order in which you are viewing them and a filter, $gt whatever the last item was. BUT that doesn't work when there are duplicates in the field on which you are sorting. To get around that you will need to index on that field PLUS some other field which is unique per record, for example, the _id field. Now, you can take the last record in the first set and look for records that are $eq the indexed value and $gt the _id OR are simply $gt the indexed value.
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Possible Duplicate:
How to create an auto incrementing field in lotus domino?
We are generating the unique sequence number for each document like an employee ID.
But user can enroll the information in different locations.
So we replicate the database into many.
Problem is, Number is generating. But the sequence number gets duplicated when the user works on different replicas.
If you must use sequential numbers, you should have the database assign a temporary number to the document when it is created and then have only one server execute an agent that assigns permanent sequential numbers to the documents on a daily or more frequent basis.
However, most of the time people just need UNIQUE numbers assigned to the documents. Using the #Unique formula generates a unique string to identify a document. Or, you could have it assign sequential numbers that include the server name as a prefix. You could use a combination of date-time and server or user information to create a unique identifier as well.
My experience is that most of the time when people say they have a requirement for sequential numbers, they're wrong, they just need unique numbers and think that sequential is the only way to do it.