I want to send out an email to all users where their birthday is today
I am using the built-in asp.net (3.5) membership. All users have a profile (stored in aspnet_Profile) which contains a date/time property called 'birthday'. I need to get a list of users email addresses from the 'aspnet_Membership' table where a users birthday is today, along with the users 'firstname' which is string property in the aspnet_Profile table.
I would like a list returned preferrably using C# LINQ.
I am not sure how to access the birthday property in the profile table, based on the way it is stored in the db table i.e name/value columns
I think you should consider changing to the much-improved table based provider:
http://weblogs.asp.net/scottgu/archive/2006/01/10/435038.aspx
This allows you to separate your data into one value per table column in the standard SQL way. This performs petter than the standard provider and it solves your problem of querying the Profiles database.
It will take a small amount of work to convert the database, but on the code side, it is just a matter of configuring in a different provider and nothing else should change. That is the beaurty of the provider pattern.
I don't use LINQ enough to give you a good answer, but the following may be the underlying SQL you need (This is how my SSMS generated it in the query designer):
SELECT aspnet_Profile.PropertyValuesString AS firstname, aspnet_Membership.Email
FROM aspnet_Profile INNER JOIN
aspnet_Membership ON aspnet_Profile.UserId = aspnet_Membership.UserId INNER JOIN
aspnet_Profile AS aspnet_Profile_1 ON aspnet_Profile.UserId = aspnet_Profile_1.UserId
WHERE (aspnet_Profile_1.PropertyNames LIKE N'birthday') AND (aspnet_Profile.PropertyNames LIKE N'firstname') AND (DATEADD(dd, 0, DATEDIFF(dd, 0,
aspnet_Profile_1.PropertyValuesString)) = DATEADD(dd, 0, DATEDIFF(dd, 0, GETDATE())))
The Profile mechanism parses the values out by splitting each name/value pair up, and then parsing them individually. You could write code to do that yourself. Or you could follow #Daniel's approach and use the alternative provider, which makes life easier. The out-of-the-box provider is a pain with the string concatenation.
Is this code in the same app? You could just use the profile object to retrieve it, if you are talking C#... what context is this piece of code in? Batch service?
Related
I've been tasked with creating an application that allows users the ability to enter data into a web form that will be saved and then eventually used to populate pdf form fields.
I'm having trouble trying to think of a good way to store the field values in a database as the forms will be dynamic (based on pdf fields).
In the app itself I will pass data around in a hash table (fieldname, fieldvalue) but I don't know the best way to convert the hash to db values.
I'm using MS SQL server 2000 and asp.net webforms. Has anyone worked on something similar?
Have you considered using a document database here? This is just the sort of problem they solve alot better than traditional RDBMS solutions. Personally, I'm a big fan of RavenDb. Another pretty decent option is CouchDb. I'd avoid MongoDb as it really isn't a safe place for data in it's current implementation.
Even if you can't use a document database, you can make SQL pretend to be one by setting up your tables to have some metadata in traditional columns with a payload field that is serialized XML or json. This will let you search on metadata while staying out of EAV-land. EAV-land is a horrible place to be.
UPDATE
I'm not sure if a good guide exists, but the concept is pretty simple. The basic idea is to break out the parts you want to query on into "normal" columns in a table -- this lets you query in standard manners. When you find the record(s) you want, you can then grab the CLOB and deserialize it as appropriate. In your case you would have a table that looked something like:
SurveyAnswers
Id INT IDENTITY
FormId INT
SubmittedBy VARCHAR(255)
SubmittedAt DATETIME
FormData TEXT
A few protips:
a) use a text based serialization routine. Gives you a fighting chance to fix data errors and really helps debugging.
b) For SQL 2000, you might want to consider breaking the CLOB (TEXT field holding your payload data) into a separate table. Its been a long time since I used SQL 2000, but my recollection is using TEXT columns did bad things to tables.
The solution for what you're describing is called Entity Attribute Value (EAV) and this model can be a royal pain to deal with. So you should limit as much as possible your usage of this.
For example are there fields that are almost always in the forms (First Name, Last Name, Email etc) then you should put them in a table as fields.
The reason for this is because if you don't somebody sooner or later is going to realize that they have these names and emails and ask you to build this query
SELECT
Fname.value fname,
LName.Value lname,
email.Value email,
....
FROM
form f
INNER JOIN formFields fname
ON f.FormId = ff.FormID
and AttributeName = 'fname'
INNER JOIN formFields lname
ON f.FormId = ff.FormID
and AttributeName = 'lname'
INNER JOIN formFields email
ON f.FormId = ff.FormID
and AttributeName = 'email'
....
when you could have written this
SELECT
common.fname,
common.lname,
common.email,
....
FROM
form f
INNER JOIN common c
on f.FormId = c.FormId
Also get off of SQL 2000 as soon as you can because you're going to really miss the UNPIVOT clause
Its also probably not a bad idea to look at previous SO EAV questions to give you an idea of problems that people have encountered in the past
I'd suggest mirroring the same structure:
Form
-----
form_id
User
created
FormField
-------
formField_id
form_id
name
value
i have two tables
asset employee
assetid-pk empid-pk
empid-fk
now, i have a form to populate the asset table but it cant because of the foreign key constraint..
what to do?
thx
Tk
Foreign keys are created for a good reason - to prevent orphan rows at a minimum. Create the corresponding parent and then use the appropriate value as the foreign key value on the child table.
You should think about this update as a series of SQL statements, not just one statement. You'll process the statements in order of dependency, see example.
Asset
PK AssetID
AssetName
FK EmployeeID
etc...
Employee
PK EmployeeID
EmployeeName
etc...
If you want to "add" a new asset, you'll first need to know which employee it will be assigned to. If it will be assigned to a new employee, you'll need to add them first.
Here is an example of adding a asset named 'BOOK' for a new employee named 'Zach'.
DECLARE #EmployeeFK AS INT;
INSERT (EmployeeName) VALUES ('Zach') INTO EMPLOYEE;
SELECT #EmployeeFK = ##IDENTITY;
INSERT (AssetName, EmployeeID) VALUES ('BOOK',#EmployeeFK) INTO ASSET;
The important thing to notice above, is that we grab the new identity (aka: EmployeeID) assigned to 'Zach', so we can use it when we add the new asset.
If I understand you correctly, are you trying to build the data graph locally before persisting to the data? That is, create the parent and child records within the application and persist it all at once?
There are a couple approaches to this. One approach people take is to use GUIDs as the unique identifiers for the data. That way you don't need to get the next ID from the database, you can just create the graph locally and persist the whole thing. There's been a debate on this approach between software and database for a long time, because while it makes a lot of sense in many ways (hit the database less often, maintain relationships before persisting, uniquely identify data across systems) it turns out to be a significant resource hit on the database.
Another approach is to use an ORM that will handle the persistence mapping for you. Something like NHibernate, for example. You would create your parent object and the child objects would just be properties on that. They wouldn't have any concept of foreign keys and IDs and such, they'd just be objects in code related by being set as properties on each other (such as a "blog post" object with a generic collection of "comment" objects, etc.). This graph would be handed off to the ORM which would use its knowledge of the mapping between the objects and the persistence to send it off to the database in the correct order, perhaps giving back the same object but with ID numbers populated.
Or is this not what you're asking? It's a little unclear, to be honest.
I want to insert the createdBy, modifiedBy, createDate, modifiedDate columns in every database table for manage user activity.
This is the first time I try to do this. Is there a best practice I could follow? Any design pattern good to manage this?
My first thought is to do this in my business logic layer, and in every business classes' insert and update method, i do something like this:
class.createDate = DateTime.Now;
or
class.modifiedDate= DateTime.Now;
class.modifiedBy = CurrentUser.Id;
or
class.createdBy = CurrentUser.Id;
Or there are much better way?
Bryan
This depends on what types of business objects you are managing, and what the rules are around what the create/modified data is needed for. In most cases, this is a database audit trail, and there is no need for this information in the business logic layer. In that case, this information should live at the database level only. If you are using an ORM, that might mean you keep the data with your objects anyway. If you are using stored procs, then they all need to know how to take a user name to tag the record with. The datetimes can be handled by setting a default value of GetDate() on the column.
Well one thing to consider is what time do you want stamped? Do you want the time of the application server or the time on the database server? I always go for the DB server. So in that case the stored procedure (or SQL statements) should be getting current time.
-Krip
You should manage CreatedDate and ModfiedDate at database label only. Default value of the CreatedDate should be Getdate()/SYSDATE and you don’t need to set this value. For ModifiedDate again set the GETDATE()/SYSDATE on every update.
You only need to pass the ModifiedBy userid from your application to the database, in case of insert set the userid for both the column and in the case of update only update the Modified by userId column.
For createdBy and modifiedBy, I usually set this in my business layer using the username of the current user. For createDate and modifiedDate I do this in the 'after' triggers in the database.
I'm looking to use a slightly modified ASP.Net Membership Provider to handle the standard user account creation/authentication/etc in a website. We have a fair amount of legacy data that I need to migrate in order to provide continuity with our existing users' saved information (like order history, wishlist, etc). [NOTE: We have to migrate anyway, so this is not the reason we're migrating data]
I'm wondering what a sensible approach is for joining this additional data to the asp.net membership tables. There are a two unique keys that I could use on the user table - UserId or email - which we will use as a surrogate for username.
My question is, what is the better access pattern (and hence foreign key) to use elsewhere in my tables for storing orders, wishlists, etc?
In HttpContext, a User object is available that contains the "Username", our email address,
but doesn't have the Guid for userId available.
I see 3 options:
I'd like to simply use the uniqueidentifier UserId for efficiency of access over a lengthy varchar email address, but it doesn't appear readily available without extra database calls to fetch it via email/login. Is there some way to get the UserId so I can make it the foreign key on different tables?
I can pass in email address (username) as the input parameter, join on userId where email address = #emailAddress, and use userId as the foreign key on other tables.
Not viable
I can store username/email address on all the other tables as a foreign key - which would be an unfortunate denormalization
Any thoughts on a best method from either a DB perspective or from an application efficiency perspective?
You can get UserId:
MembershipUser myObject = Membership.GetUser();
string UserID = myObject.ProviderUserKey.ToString();
or maybe (please, check it)
string userId = Membership.GetUser(User.Identity.Name).ProviderUserKey.ToString();
I will explain problem with an example:
There is two table in my database, named entry, tags
There is a column named ID_ENTRY in both table. When I add a record to table, entry, I have to take the ID_ENTRY of last added record and add it to table, tags. How can I do it?
The only way to do this is with multiple statements. Using dynamic sql you can do this by separating each statement in your query string with a semi-colon:
"DECLARE #ID int;INSERT INTO [Entry] (...) VALUES ...; SELECT #ID = scope_identity();INSERT INTO [TAGS] (ID_ENTRY) VALUES (#ID);"
Make sure you put this in a transaction to protect against concurrency problems and keep it all atomic. You could also break that up into two separate queries to return the new ID value in the middle if you want; just make sure both queries are in the same transaction.
Also: you are using parameterized queries with your dynamic sql, right? If you're not, I'll personally come over there and smack you 10,000 times with a wet noodle until you repent of your insecure ways.
Immediatly after executing the insert statement on first table, you should query ##IDENTITY doing "SELECT ##identity". That will retrieve the last autogenerated ID... and then just insert it on the second table.
If you are using triggers or something that inserts rows... this may be not work. Use Scope_Identity() instead of ##IDENTITY
I would probably do this with an INSERT trigger on the named entry table, if you have all of the data you need to push to the tags table available. If not, then you might want to consider using a stored procedure that creates both inside a transaction.
If you want to do it in code, you'll need to be more specific about how you are managing your data. Are you using DataAdapter, DataTables, LINQ, NHibernate, ...? Essentially, you need to wrap both inserts inside a transaction of some sort so that either inserts get executed or neither do, but the means to doing that depend on what technology you are using to interact with the database.
If you use dynamic sql, why not use Linq to Entity Framework, now EF is the recommend data access technology from Microsoft (see this post Clarifying the message on L2S Futures from ADO.NET team blog), and if you do an insert with EF the last identity id will available for you automatically, I use it all the time it's easy.
Hope this helps!
Ray.