Given a table with startDate and endDate columns how do I query for records where the periods overlap. The dates currently use DateField type. Would changing the type to DateRangeField help with this query? We are using Cassandra with Solr.
i am just sharing a data model for records where the periods overlap event
CREATE TABLE event (
start_date date,
id timeuuid,
end_date date,
PRIMARY KEY ((start_date), id))
SELECT * FROM event WHERE start_date =date;
i think if you create your data model like this and query like this your problem will be solve.
Related
I have a ClickHouse schema as following, MergeTree is in question:
(
hotel String,
staff_member String,
task_number Float64,
date DateTime
)
PRIMARY KEY (hotel, date)
ORDER BY (hotel, date)
My aggregation is as following:
SELECT
staff_member,
sum(task_number)
FROM ...
WHERE
hotel = {hotel}
AND date >= {first_date}
AND date <= {top_date}
GROUP BY staff_member
Basically, I'm aggregating the number of tasks of a staff member over a period of time, but the aggregation is kind of slow. I have a feeling the primary key is off and I need to rework it.
First that comes to mind would be to change the key to (hotel, staff_member, date) since I'm grouping by the staff_member
I'm thankful for any help!
I have 2 database tables called Spend, and VendorSpend. The columns used in the Spend table are called VendorID, VendorName, RecordDate, and Charges. The VendorSpend table contains VendorID and VendorName but with distinct data (one record for each unique VendorID). I need a simple way to add a column to the VendorSpend table called Aug2015, this column will contain the SUM of each Vendor's charges within that month time period. It will be calculated based on this query:
Select Sum(Charges)
from Spend
where RecordDate >= '2015-08-01' and RecordDate <= '2015-08-31'
Keep in mind this will need to be called whenever new data is inserted into the Spend table and the VendorSpend table will need to update based on the new data. This will happen every month so actually a new column will need to be added and the data be calculated every month.
Any assistance is greatly appreciated.
Create a user-defined function that you pass a VendorID and Date to and which does your SELECT:
Select Sum(Charges)
from Spend
where VendorID=#VendorID
AND DATEDIFF(month, RecordDate, #Date) = 0
Now personally, I would stop right there and use the function to select your data at query time, rather than adding a new column to your table.
But treating your question as academic, you can create a computed column called [Aug2015] in VendorSpend that passes [VendorID] and '08/01/2015' to this function and it will contain the desired result.
I have a SELECT that retrieves ROWS comparing a DATETIME field to the highest available value of another TABLE.
The Two Tables have the following structure
DeletedRecords
- Id (Guid)
- RecordId (Guid)
- TableName (varchar)
- DeletionDate (datetime)
And Another table which keep track of synchronizations using the following structure
SynchronizationLog
- Id (Guid)
- SynchronizationDate (datetime)
In order to get all the RECORDS that have been deleted since the last synchronization, I run the following SELECT:
SELECT
[Id],[RecordId],[TableName],[DeletionDate]
FROM
[DeletedRecords]
WHERE
[TableName] = '[dbo].[Person]'
AND [DeletionDate] >
(SELECT TOP 1 [SynchronizationDate]
FROM [dbo].[SynchronizationLog]
ORDER BY [SynchronizationDate] DESC)
The problem occurs if I do not have synchronizations available yet, the T-SQL SELECT does not return any row while it should returns all the rows cause there are no synchronization records available.
Is there a T-SQL function like COALESCE that I can use with DateTime?
Your subquery should look like something like this:
SELECT COALESCE(MAX([SynchronizationDate]), '0001-01-01')
FROM [dbo].[SynchronizationLog]
It says: Get the last date, but if there is no record (or all values are NULL), then use the '0001-01-01' date as start date.
NOTE '0001-01-01' is for DATETIME2, if you are using the old DATETIME data type, it should be '1753-01-01'.
Also please note (from https://msdn.microsoft.com/en-us/library/ms187819(v=sql.100).aspx)
Use the time, date, datetime2 and datetimeoffset data types for new work. These types align with the SQL Standard. They are more portable. time, datetime2 and datetimeoffset provide more seconds precision. datetimeoffset provides time zone support for globally deployed applications.
EDIT
An alternative solution is to use NOT EXISTS (you have to test it if its performance is better or not):
SELECT
[Id],[RecordId],[TableName],[DeletionDate]
FROM
[DeletedRecords] DR
WHERE
[TableName] = '[dbo].[Person]'
AND NOT EXISTS (
SELECT 1
FROM [dbo].[SynchronizationLog] SL
WHERE DR.[DeletionDate] <= SL.[SynchronizationDate]
)
I have got data from table. There is one datetime field in table. Field name is createdon
In select query I pass two datetime parameters Now I want all data from table where createdon field is not equals to these two date time parameters.
A literal interpretation.
SELECT *
FROM TBL
WHERE createdon NOT IN (#date1, #date2);
Is there a way (without creating a formula datevalue(datetime) field) to aggregate a SOQL query on the date portion of a datetime field? For example, I'd like to do something like:
select datevalue(datetimeField), count(Id) from object__c group by datevalue(datetimeField)
While you can't group on a datetime field directly, there are a number of date/time functions for aggregates, so that you can group by part of the dateTime value. For example here's a query that'll show the number of account records created on each date.
select day_only(createdDate) createdonDate,
count(createdDate) numCreated
from account
group by day_only(createdDate)
order by day_only(createdDate) desc
The docs have details of all the date functions for aggregates.
day_only() returns the date part of a dateTime field.
According to the DescribeSObjectResult, datetime fields are not "groupable".