I have data, let's take a sample;
Currency
Account
FiatValue
BTC
Account1
10
ETH
Account2
6
BTC
Account2
10
Is there any way I can use a view to aggregate this in some way. I'd like to end up with an aggregate view of all Accounts and their total FiatValue across all Currencies. I was thinking of writing some PowerShell to grab the data in this table, and update a new table via a script, but thought possibly I can achieve something similar within SQL?
Goal
Account
FiatValue
Account1
10
Account2
16
If you can write a SQL query, you can save it as a View. This one is very simple:
create or alter view AccountSummary
as
select AccountId, sum(FiatValue) FiatValue
from Account
group by AccountId
Related
Let's say I have a database named as db1 and a table with 10000 records, and I have a user named user1 in the database.
Then if user1 enters a query in MS SQL server:
select * from tb1, then it should return only 100 records.
there is only option to grant read or write permission to whole table.
This is too long for a comment.
I don't think there is any built-in database method for doing this. Often, applications will "page" results. Iff the application runs inselect * from tbl1, then the application only fetches 100 rows. Note: There is no concept of "top rows" in SQL without an order by clause. SQL tables represent unordered sets.
If you want to limit users to seeing only 100 rows, then you can use a view:
create view v_table as
select top 100 t.* from tbl1 t;
Also note that without an order by clause, this might return different rows on different executions.
I have to find a leader of a group and update employee's leader. I am not sure how to proceed with this in DataStage.
I have an employee table as shown below
Emp_id mgr_id leader_id
1 100 400
101 201 500
3 202 600
I get a file to update employee table when an employee changes group. Change code = CHG means it is a job/group change.
I do an equi join between file and employee table and can update manager id. At the same time, I need to find a leader. I need to get all the employees who report to that top level leader and use as the leader id's for every employee.
File:
emp_id mgr_id chg_cd
1 102 CHG
101 301 CHG
File Row 1: There is change in manager for emp_id = 1; need to update mgr_id, leader_id in employee table
File Row 2: There is change in manager for emp_id = 102, need to change mgr_id and leader_id for in employee table
Can you please suggest me on how to proceed with this in DataStage?
ok this problem requires a solution with recursion. As DataStage has no way to do it (if the levels between managers and leaders are variable).
So load the data into a database table and use recursive SQL to query it - this will provide you the solution you are asking for.
Example:
Extract all leaders with their business units they manage inculding different levels) with the recursive SQL statement and use this data in da DataStage lookup to enrich the file data.
I have a scenario where multiple loopings are causing the system resource error.
I need some help with map of map syntax or coding sample for this requirement.
Requirement is:
Account has 1 or more ReportCard records.
ReportCard has Account and Contact.
Now i need to get the list of ReportCards and filter by 1 per contact and recently created records only.
If ReportCard has 2 records with same contact, include only recently created.
// get list of unique accounts from the set
list<Account> accList = new list<Account >([SELECT Id,Average_of_Pulse_Check_Recommend_Score_N__c,Average_of_Recommend_Score_Lanyon_N__c,Average_of_Touchpoint_Recommend_Score_N__c,Average_of_Touch_Point_Satisfaction_N__c FROM Account WHERE Id in:AccIds]);
list<ReportCard__c> allRCList = new list<ReportCard__c>([SELECT Id,Net_Promoter_text__c,CreatedDate, Contact__c, Account__c, RecordTypeID, Touchpoint_Satisfaction_text__c FROM ReportCard__c WHERE Account__c in:accList Order By Account__c, CreatedDate Desc]);
List<ReportCard__c> rcListbyAccounts = new List<ReportCard__c>();
for(Account acc:accList)
{
Any help would be appreciated.
Thanks
I'm not sure I understand your situation correctly. You've skipped the for loop - I strongly suspect any issues you have there sit in the loop rather than in the queries.
Looks like you should read about using relationship queries (salesforce versions of JOIN in regular database): http://www.salesforce.com/us/developer/docs/soql_sosl/Content/sforce_api_calls_soql_relationships.htm
Pay special attention to subqueries (which behave similar to how a related list behaves on record's detail page).
From what I see I'd say you don't need to query for Accounts at all, or at least not like that. This will work equally well:
SELECT Id,Net_Promoter_text__c,CreatedDate, Contact__c, Account__c, ...
FROM ReportCard__c
WHERE Account__c in:accIds
ORDER BY Account__c, CreatedDate Desc
Now lets attack this:
List of ReportCards and filter by 1 per contact and recently created
records only. If ReportCard has 2 records with same contact, include
only recently created.
I'd reverse it - I'd start the query from Contact level, go down to the related list of Report Cards and pick the latest one. That way it eliminates the issue with duplicate contacts for you. Something like this:
SELECT Id, Name, Email,
(SELECT Id, Net_Promoter_text__c, CreatedDate, Account__c, Account__r.Name, Account__r.Average_of_Pulse_Check_Recommend_Score_N__c
FROM ReportCards__r
WHERE Account__c IN :accIds
ORDER BY CreatedDate DESC
LIMIT 1)
FROM Contact
WHERE AccountId IN :accIds
This goes from Contact "down" to Report Cards (via the relationship name ReportCards__r) and then "up" from Card to Account via Account__r.Name, Account__r.Average_of_Pulse_Check_Recommend_Score_N__c...
Hey Salesforce experts,
I have a question on query account information efficiently. I would like to query accounts based on the updates in an activityHistory object. The problem I'm getting is that all the accounts are being retrieved no matter if there's "complete" activeHistory or not. So, Is there a way I can write this query to retrieve only accounts with activeHistory that has status="complete" and Type_for_reporting='QRC'?
List<Account> AccountsWithActivityHistories = [
SELECT
Id
,Name
,( SELECT
ActivityDate
,ActivityType
,Type_for_Reporting__c
,Description
,CreatedBy.Name
,Status
,WhatId
FROM ActivityHistories
WHERE Status ='complete' and Type_for_Reporting__c = 'QRC'
)
FROM Account
];
You have a WHERE clause on the histories but you still miss one on the Account level.
For example this would return only Accounts that have Contacts:
SELECT Id, Name
FROM Account
WHERE Id IN (SELECT AccountId FROM Contact) // try with NOT IN too
With Activities it's trickier because they don't like to be used in WHERE in that way.
http://www.salesforce.com/us/developer/docs/officetoolkit/Content/sforce_api_calls_soql_select.htm
The following objects are not currently supported in subqueries:
ActivityHistory
Attachments
Event
EventAttendee
Note
OpenActivity
Tags (AccountTag, ContactTag, and all other tag objects)
Task
Additionally the fine print at the bottom of ActivityHistory definition is also a bit discouraging.
The following restrictions on users who don’t have “View All Data” permission help prevent performance issues:
In the main clause of the relationship query, you can reference only
one record. For example, you can’t filter on all records where the
account name starts with ‘A’; instead, you must reference a single
account record.
You can’t use WHERE clauses.
You must specify a limit of 499 or fewer on the number of rows returned in the list.
You must sort on ActivityDate in ascending order and LastModifiedDate in descending order; you can display nulls last. For
example: ORDER BY ActivityDate ASC NULLS LAST, LastModifiedDate DESC.
Looks like you will need multiple queries. Go for Task (or Event, depending for which the custom field is visible), compose a set of AccountIds and then query the Accounts?
Or you can manually filter through list from your original query, copying accounts to helper list:
List<Account> finalResults = new List<Account>();
for(Account a : [SELECT...]){
if(!a.ActivityHistories.isEmpty()){
finalResults.add(a);
}
}
Is there a way in MS access to return a dataset between a specific index?
So lets say my dataset is:
rank | first_name | age
1 Max 23
2 Bob 40
3 Sid 25
4 Billy 18
5 Sally 19
But I only want to return those records between 'rank' 2 and 4, so my results set is Bob, Sid and Billy? However, Rank is not part of the table, and this should be generated when the query is run. Why don't I use an autogenerated number, because if a record is deleted, this will be inconsistent, and what if I wanted the results in reverse!
This obviously very simple, and the reason I ask is because I am working on a product catalogue and I am looking for a more efficient way of paging through the returned dataset, so if I only return 1 page worth of data from the database this is obviously going to be quicker then return a complete set of 3000 records and then having to subselect from that set!
Thanks R.
Original suggestion:
SELECT * from table where rank BETWEEN 2 and 4;
Modified after comment, that rank is not existing in structure:
Select top 100 * from table;
And if you want to choose subsequent results, you can choose the ID of the last record from the first query, say it was ID 101, and use a WHERE clause to get the next 100;
Select top 100 * from table where ID > 100;
But these won't give you what you're looking for either, I bet.
How are you calculating rank? I assume you are basing it on some data in another dataset somewhere. If so, create a function, do a table join, or do something that can calculate rank based on values in other table(s), then you can do queries based on the rank() function.
For example:
select *
from table
where rank() between 2 and 4
If you are not calculating rank based on some data somewhere, there really isn't a way to write this query, and you might as well be returning three random rows from the table.
I think you need to use a correlated subquery to calculate the rank on the fly e.g. I'm guessing the rank is based on name:
SELECT T1.first_name, T1.age,
(
SELECT COUNT(*) + 1
FROM MyTable AS T2
WHERE T1.first_name > T2.first_name
) AS rank
FROM MyTable AS T1;
The bad news is the Access data engine is poorly optimized for this kind of query; in my experience, performace will start to noticeably degrade beyond a few hundred rows.
If it is not possible to maintain the rank on the db side of the house (e.g. high insertion environment) consider doing the paging on the client side. For example, an ADO classic recordset object has properties to support paging (PageCount, PageSize, AbsolutePage, etc), something for which DAO recordsets (being of an older vintage) have no support.
As always, you'll have to perform your own timings but I suspect that when there are, say, 10K rows you will find it faster to take on the overhead of fetching all the rows to an ADO recordset then finding the page (then perhaps fabricate smaller ADO recordset consisting of just that page's worth of rows) than it is to perform a correlated subquery to only fetch the number of rows for the page.
Unfortunately the LIMIT keyword isn't available in MS Access -- that's what is used in MySQL for a multi-page presentation. If you can write an order key into the results table, then you can use it something like this:
SELECT TOP 25 MyOrder, Etc FROM Table1 WHERE MyOrder in
(SELECT TOP 55 MyOrder FROM Table1 ORDER BY MyOrder DESC)
ORDER BY MyOrder ASCENDING
If I understand you correctly, there is ionly first_name and age columns in your table. If this is the case, then there is no way to return Bob, Sid, and Billy with a single query. Unless you do something like
SELECT * FROM Table
WHERE FirstName = 'Bob'
OR FirstName = 'Sid'
OR FirstName = 'Billy'
But I think that this is not what you are looking for.
This is because SQL databases make no guarantee as to the order that the data will come out of the database unless you specify an ORDER BY clause. It will usually come out in the same order it was added, but there are no guarantees, and once you get a lot of rows in your table, there's a reasonably high probability that they won't come out in the order you put them in.
As a side note, you should probably add a "rank" column (this column is usually called id) to your table, and make it an auto incrementing integer (see Access documentation), so that you can do the query mentioned by Sev. It's also important to have a primary key so that you can be certain which rows are being updated when you are running an update query, or which rows are being deleted when you run a delete query. For example, if you had 2 people named Max, and they were both 23, how you delete 1 row without deleting the other. If you had another auto incrementing unique column in there, you could specify the unique ID in your query to delete only one.
[ADDITION]
Upon reading your comment, If you add an autoincrement field, and want to read 3 rows, and you know the ID of the first row you want to read, then you can use "TOP" to read 3 rows.
Assuming your data looks like this
ID | first_name | age
1 Max 23
2 Bob 40
6 Sid 25
8 Billy 18
15 Sally 19
You can wuery Bob, Sid and Billy with the following QUERY.
SELECT TOP 3 FirstName, Age
From Table
WHERE ID >= 2
ORDER BY ID