I have a contract table with BeginDate fields but no end date on a SQL Server 2000 database (cringe). I'm using an SSIS package designed in the 2008 environment to move data from this table into a staging db for a data warehouse. I need to compute the end date.
The end date is the next contract start date for the customer minus one day.
In anything but SQL Server 2000 this would be easy enough to do with a CTE. I used one strategy that used Row Number to merge to sets, even that won't work here.
My strategy will be to pull the dates through a datasource component. Something like this:
SELECT CustomerId, ContractStartDate FROM Contracts
Then, I'll use a script component and override the ProcessInput method to loop through the result set and add the end date as an output value.
This seems like a pathetic method, but given my constraints, is probably the best method. Can anyone think of any other options?
After some further research I found that it isn't possible to traverse the input buffer at will.
The solution is a bit counter-intuitive to the question. Instead of identifying and modifying the next row, the best you can do is modify the current row based on the previous value. This means that the data will need to be evaluated from the greatest date to the smallest date within the customer id.
For the sake of continuity, I'll keep my example within the context of the original question.
Assume we have are input data for the script component. Add a sort component to order the record set by CustomerID, then by ContractStartDate descending.
Then in the script component, add CustomerID and ContractStartDate as input and add ContractEndDate as an output value.
Override the Input0_ProcessInputRow. The code to do this is generated by default.
Add some properties to keep track of the previous start date and previous customer, and set the current row's end date value based on the previous row.
Your script will look something like this:
public DateTime? PreviousRowStartDate { get; set; }
public string PreviousRowCustomerID { get; set; }
public int KnownContractPeriod { get; set; }
int defaultContractPeriod = 12;
public override void Input0_ProcessInputRow(Input0Buffer Row)
{
if (PreviousRowCustomerID == Row.CustomerID)
{
Row.ContractEndDate= PreviousRowStartDate.Value.AddDays(-1);
}
else
{
Row.ContractEndDate= Row.ContractStartDate.AddMonths(defaultContractPeriod).AddDays(-1);
}
PreviousRowCustomerID = Row.CustomerID;
PreviousRowStartDate = Row.ContractStartDate;
}
This breaks down when dealing with the very first contract (the customers latest). For this reason, I've included a default contract period.
This problem might actually come up to bite me, but it's difficult to say right now as most contracts here are 12 months in length.
Related
Following viewmodel used in a view is supposed to display a StartDate as, say 9/30/2015. But it is displaying as 9/30/2015 12:00:00 AM. How can I make it display without time while using DataAnnotaion? I know I can use #Model.StartDate.ToString("MM/dd/yyy") inside view to display date only. But that would mean you have to do it in every view that is using the following ViewModel:
ViewModel:
...
[DisplayFormat(DataFormatString = "{0:MM/dd/yyyy}")]
public DateTime StartDate { get; set; }
...
UPDATE
The corresponding model class of the above ViewModel already has the following DataAnnotation that correctly creates the data type in SQL Server table as Date; and when you run a query on the corresponding table in SSMS it correctly displays the StartDate column's data with dates only, say, 9/30/2015 etc.)
Model
...
[DataType(DataType.Date)]
public DateTime StartDate { get; set; }
...
StartDate in the sql db is in fact Date only. Moreover, if I run a query on SSMS it correctly returns date only.
There are two solutions to your problem. As per your comments, you are currently using #Model.StartDate to display a date.
You can either do this:
#Model.StartDate.ToString("d")
Or, you can use a model based approach in your ViewModel and do this:
[DataType(DataType.Date)]
public DateTime StartDate {get;set;}
Then, in your view use:
#Html.DisplayFor(m => m.StartDate)
I am writing an integration piece between Drupal/Ubercart and a in-house admin system.
The customer uses Ubercart products with attributes (e.g. a Plaque, which can contain a name, a company, a registration date and month). When an order is placed, the values entered for the attributes are written to uc_order_products, where the data field contains the actual values entered by the user. As far as I can tell, this is the only place where product attributes values, as entered by an end user to place an order, is stored.
The encoded attribute values uses a format seen all over Drupal tables to encode objects:
a:3:{s:10:"attributes";a:4:{s:26:"Name (to appear on plaque)";a:1:{i:0;s:10:"Some
Namee";}s:7:"Company";a:1:{i:0;s:28:"Some Company Name Goes here_";}s:19:"Certification
Month";a:1:{i:0;s:0:"";}s:18:"Certification Year";a:1:
{i:0;s:4:"2011";}}s:9:"shippable";s:1:"1";s:6:"module";s:10:"uc_product";}
And expanded, it looks like this:
a:3:
{
s:10:"attributes";
a:4:
{
s:26:"Name (to appear on plaque)";
a:1:
{
i:0;
s:10:"Some Namee";
}
s:7:"Company";
a:1:
{
i:0;
s:28:"Some Company Name Goes Herep";
}
s:19:"Certification Month";
a:1:
{
i:0;
s:0:"";
}
s:18:"Certification Year";
a:1:
{
i:0;
s:4:"2011";
}
}
s:9:"shippable";
s:1:"1";
s:6:"module";
s:10:"uc_product";
}
I there a simple way to get to the individual field values within this text using SQL? I can write a SQL function to go look for specifics, but I'd like to know if someone knows of an existing MySQL approach (perhaps within Drupal) which would do this.
Thanks!
That's a serialized array, meaning data that was processed by PHP's serialize() function before Drupal inserted it into the database. Use the opposite function unserialize() to turn that string back into an array.
Don't know if any built-in solution exists, but I ended up writing a SQL Function which takes as parameter text such as Name (to appear on plaque). The function then locates the text and extracts the succeeding { ... } block and from it retrieves the corresponding string value. Rough, but works in this case.
If someone has a better solution, I'd like to hear about it!
I have an application that uses a few data warehousing principles such as dimensional modeling to do reporting on a fairly simple database.
An example (simplified) entity named Call looks like this:
public virtual long Id { get; set; }
public virtual string OriginatorNumber { get; set; }
public virtual string DestinationNumber { get; set; }
public virtual DateDimension DateDimension { get; set; }
A few of the properties of the real model have been removed as they are irrelevant. The simplified DateDimension looks like this:
public virtual long Id { get; set; }
public virtual DateTime Date { get; set; }
public virtual int DayOfMonth { get; set; }
public virtual int Weekday { get; set; }
There are a LOT more columns like this - they are prepopulated for the current decade by application setup. So each date in the entire decade has a row in this table, and each Call has a link to the date that it occured. This is all mapped in Fluent NHibernate and working fine.
If I want to do some reporting, I can do this easily with the improved NHibernate LINQ provider in 3.0. We would like to use LINQ for the improved maintainability it gives us, but if we really MUST, we'll consider HQL, ICriteria or even plain SQL.
So say I want to build a report that shows the number of calls from a certain number, divided by the day of the week they occur. I can do that easily this way:
var query = Calls
.Where(c => c.OriginatorNumber == "402")
.GroupBy(c => c.DateDimension.Weekday)
.Select(g => new { Day = g.Key, Calls = g.Count() } );
In this example, "Calls" is basically an IQueryable returned from NHibernates LINQ provider (Query) through a repository interface. The query above gives me the correct results, NHibernate Profiler shows me that the SQL is pretty optimal, all is well.
However, if I want to do something slightly more advanced, I get stuck. Say I want the average number of calls per weekday. Not too far from the above, right? I just need to figure out the number of unique dates each weekday has in the result set, divide the total number of calls by it, and we're all set - right? Well, no, this is where I start to hit the limitations of the NHibernate LINQ provider. With LINQ to objects I could construct a query to do it - something along the lines of
.Select(g => g.Count() / g.GroupBy(c => c.DateDimension.Date).Count());
However, this does not convert into the correct query when using it in NHibernate. Rather, it turns both .Count() calls in the above to the same count(*) of call records, so the result is always 1.
I COULD of course just query for each call, weekday and date as a new anonymous object, then do the math on the application side, but according to conventional wisdom, That's Just Wrong (tm). I could end up doing it in desperation, tho, even tho it means pain when the table grows to a million++ calls.
The below is an SQL query that gives me the result I am looking for.
select ss.Weekday, AVG(cast(ss.Count as decimal))
from
(
select dd.Weekday, dd.Date, COUNT(*) as Count
from Call c
left outer join DateDimension dd
on c.DateDimension_id = dd.Id
where c.OriginatorNumber = '402'
group by dd.Weekday, dd.Date
) ss
group by ss.Weekday
order by ss.Weekday
Is it possible to do this with the NHibernate LINQ provider? Or, if that is not possible, how close can I get before I have to let the application fetch the intermediary result and do the rest?
There are a lot of things you can't do with the LINQ provider. Using HQL or CreateCriteria is just something you'll have to accept with NHibernate.
I haven't tried it, but it looks like you should be able to do what you want to do using HQL or CreateCriteria (with DetatchedCriteria).
If you are desperate you can also fall back to plain SQL using CreateSqlQuery.
I have 3 related objects (Entry, GamePlay, Prize) and I'm trying to find the best way to query them for what I need using NHibernate. When a request comes in, I need to query the Entries table for a matching entry and, if found, get a) the latest game play along with the first game play that has a prize attached. Prize is a child of GamePlay and each Entry object has a GamePlays property (IList).
Currently, I'm working on a method that pulls the matching Entry and eagerly loads all game plays and associated prizes, but it seems wasteful to load all game plays just to find the latest one and any that contain a prize.
Right now, my query looks like this:
var entry = session.CreateCriteria<Entry>()
.Add(Restrictions.Eq("Phone", phone))
.AddOrder(Order.Desc("Created"))
.SetFetchMode("GamePlays", FetchMode.Join)
.SetMaxResults(1).UniqueResult<Entry>();
Two problems with this:
It loads all game plays up front. With 365 days of data, this could easily balloon to 300k of data per query.
It doesn't eagerly load the Prize child property for each game. Therefore, my code that loops through the GamePlays list looking for a non-null Prize must make a call to load each Prize property I check.
I'm not an nhibernate expert, but I know there has to be a better way to do this. Ideally, I'd like to do the following (pseudocode):
entry = findEntry(phoneNumber)
lastPlay = getLatestGamePlay(Entry)
firstWinningPlay = getFirstWinningGamePlay(Entry)
The end result of course is that I have the entry details, the latest game play, and the first winning game play. The catch is that I want to do this in as few database calls as possible, otherwise I'd just execute 3 separate queries.
The object definitions look like:
public class Entry
{
public Guid Id {get;set;}
public string Phone {get;set;}
public IList<GamePlay> GamePlays {get;set;}
// ... other properties
}
public class GamePlay
{
public Guid Id {get;set;}
public Entry Entry {get;set;}
public Prize Prize {get;set;}
// ... other properties
}
public class Prize
{
public Guid Id {get;set;}
// ... other properties
}
The proper NHibernate mappings are in place, so I just need help figuring out how to set up the criteria query (not looking for HQL, don't use it).
since you are doing this in each request maybe it should be better to set up two formula-properties in your entity.
The first one should fetch the latest Gameplay-Id and the other the first Gameplay-Id with a not Null property
this could be as such in the xml mapping file of Entry
<property name="LatestGameplay" formula="select top(1)gp.Id from Gameplay gp where gp.FK_EntryId = PK_EntryId order by gp.InsertDate desc" />
this leaves you with the Gameplay Id's on the Entry entity and after you fetch it it would require another round trip to the DB to GetById-fetch the gameplay's
Alternatively you could work-around using filters.
Set the collection back to "lazy"
and create these nice filters
Gameplay latest = NHibernateSession.CreateFilter(entry.GamePlays , "order by InsertDate desc").SetMaxResults(1).SetFirstResult(1).UniqueResult<Gameplay>();
Gameplay winner = NHibernateSession.CreateFilter(entry.GamePlays , "where FK_PrizeId is not null order by InsertDate asc ").SetMaxResults(1).SetFirstResult(1).UniqueResult<Gameplay>();
And IFilters can be used in a multiquery as so have 2 db hits: one for the original Entry and one for the multiquery.
Last but not least, you could define 2 bags in the Entry entity, one IList<GamePlay> Latest and one IList<Gameplay> Winner which in the Entry mapping file would be filtered with the appropriate query (although i don't remember now if you can define TOP clauses in the filters) and set those as non-lazy. Then with a single round-trip you can have all the data you want with the following (ugly) syntax
Entry entry = findEntry(phoneNumber);
Gameplay winner = entry.Winner[0]; //check this if null first
Gameplay Latest = entry.Latest[0]; //ditto
note that of all the solutions the 3rd is the one that provides a mechanism to generate additional queries, as the bag can be used in a Criteria/HQL query
I am having hard times convincing NHibernate (EF was able to do it) to filter based on the Hour property of a DateTime entity property. My entity goes something like :
public class Invoice {
// ...
public DateTime Time { get; set; }
// ...
}
I need to retrieve all the invoices that were "made" at a certain hour (let's say 22). A possible query could be :
from i in s.Linq<Invoice>()
where i.Type.Id == Invoice.Type.Local &&
i.TimeOfRegister.Hour == 22
select i
However I am being thrown an exception stating that the property Hour of TimeOfRegister could not be resolved...
LE : The details of the exception : could not resolve property: TimeOfRegister.Hour of: MyCompany.Entities.Invoice
Sounds like NHibernate does not see the a DateTime as a component which has properties it can select on, it sees it as a single property. You probably have to use a function to obtain the Hour part of the DateTime.
In HQL for SqlServer2005: hour(i.TimeOfRegister)
Well I was advised by a colleague to take another route :
Define an int (or a byte) property on the entity (let's say "HourOfRegister") and then in the mapping class map it to a formula :
Map(a => a.HourOfRegister).Formula("DATEPART(HOUR, TimeOfRegister)");
Then I can use it in the query as I like it.