We have a db driven asp.net /sql server website and would like to investigate how we can allow users to create a new database category and fields - is this crazy?. Is there any examples of such organic websites out there - the fact that I havent seen any maybe suggest i am?
Interested in the best approach which would allow some level of control by Admin.
I've implemented things along these lines with a dictionary table, rather than a more traditional table.
The dictionary table might look something like this:
create table tblDictionary
(id uniqueidentifier, --Surrogate Key (PK)
itemid uniqueidentifier, --Think PK in a traditional database
colmn uniqueidentifier, --Think "column name" in a traditional database
value nvarchar, --Can hold either string or number
sortby integer) --Sorting columns may or may not be needed.
So, then, what would have been one row in a traditional table would become multiple rows:
Traditional Way (of course I'm not making up GUIDs):
ID Type Make Model Year Color
1 Car Ford Festiva 2010 Lime
...would become multiple rows in the dictionary:
ID ITEMID COLUMN VALUE
0 1 Type Car
1 1 CarMake Ford
2 1 CarModel Festiva
3 1 CarYear 2010
4 1 CarColor Lime
Your GUI can search for all records where itemid=1 and get all of the columns it needs.
Or it can search for all records where itemid in (select itemid from tblDictionary where column='Type' and value='Car' to get all columns for all cars.
In theory, you can put the user-defined types into the same table (Type='Type') as well as the user-defined columns that that Type has (Type='Column', Column='ColumnName'). This is where the sortby column comes into it - to help build the the GUI in the correct order, if you don't want to rely on something else.
A number of times, though, I have felt that storing the user-defined dictionary elements in the dictionary was a bit too much drinking-the-kool-aid. Those can be separate tables because you already know what structure they need at design time. :)
This method will never have the speed or quality of reporting that a traditional table would have. Those generally require the developer to have pre-knowledge of the structures. But if the requirement is flexibility, this can do the job.
Often enough, what starts out as a user-defined area of my sites has had a later project to normalize the data for reporting, etc. But this allows users to get started in a limited way and work out their requirements before engaging the developers.
After all that, I just want to mention a few more options which may or may not work for you:
If you have SharePoint, users already have the ability to create
their own lists in this way.
Excel documents in a shared folder that are saved in such a way
to allow multiple simultaneous edits would also serve the purpose.
Excel documents, stored on the webserver and accessed via ODBC
would also serve as single-table databases like this.
Related
I'm trying to get a better understanding of what Rows and Rowsets are used for in PeopleCode? I've read through PeopleBooks and still don't feel like I have a good understanding. I'm looking to get more understanding of these as it pertains to Application Engine programs. Perhaps walking through an example may help. Here are some specific questions I have:
I understand that Rowsets, Row, Record, and Field are used to access component buffer data, but is this still the case for stand alone Application Engine programs run via Process Scheduler?
What would be the need or advantage to using these as opposed to using SQL objects/functions (CreateSQL, SQLExec, etc...)? I often see in AE programs where the CreateRowset object is instantiated and uses a .Fill method with a SQL WHERE Clause and I don't quite understand why a SQL was not used instead.
I've seen in PeopleBooks that a Row object in a component scroll is a row, how does a component scroll relate to the row? I've seen references to rows having different scroll levels, is this just a way of grouping and nesting related data?
After you have instantiated the CreateRowset object, what are typical uses of it in the program afterwards? How would you perform logic (If, Then, Else, etc..) on data retrieved by the rowset, or use it to update data?
I appreciate any insight you can share.
You can still use Rowsets, Rows, Records and fields in stand alone Application Engines. Application Engines do not have component buffer data as they are not running within the context of a component. Therefore to use these items you need to populate them using built-in methods like .fill() on a rowset, or .selectByKey() on a record.
The advantage of using rowsets over SQL is that it makes the CRUD easier. There are built-in methods for selecting, updating, inserting and deleting. Additionally you don't have to worry about making a large number of variables if there were multiple fields like you would with a SQL object. Another advantage is when you do the fill, the data is read into memory, where if you looped through the SQL, the SQL cursor would be open longer. The rowset, row, record and field objects also have a lot of other useful methods such as allowing you to executeEdits (validation) or copy from one rowset\row\record to another.
This question is a bit less clear to me but I'll try and explain. If you have a Page, it would have a level 0 row. It then could have multiple Level 1 rowsets. Under each of those it could have a level 2 rowsets.
Level0
/ \
Level1 Level1
/ \ / \
Level2 Level2 Level2 Level2
If one of your level1 rows had 3 rows, then you would find 3 rows in the Rowset associated with that level1. Not sure I explained this to answer what you need, please clarify if I can provide more info
Typically after I create a rowset, I would loop through it. Access the record on each row, do some processing with it. In the example below, I look through all locked accounts and prefix their description with LOCKED and then updated the database.
.
Local boolean &updateResult;
local integer &i;
local record &lockedAccount;
Local rowset &lockedAccounts;
&lockedAccounts = CreateRowset(RECORD.PSOPRDEFN);
&lockedAccounts.fill("WHERE acctlock = 1");
for &i = 1 to &lockedAccounts.ActiveRowCount
&lockedAccount = &lockedAccounts(&i).PSOPRDEFN;
if left(&lockedAccount.OPRDEFNDESCR.value,6) <> "LOCKED" then
&lockedAccount.OPRDEFNDESCR.value = "LOCKED " | &lockedAccount.OPRDEFNDESCR.value;
&updateResult = &lockedAccount.update();
if not &updateResult then
/* Error handle failed update */
end-if;
end-if;
End-for;
I'm struggling to decide what database schema to use. One large table, or many small (though more difficult to manage).
I have 10 templates each with their own text fields. I am trying to store the text for the templates in a database and then when the web page is called I will show the correct text in the html template. Because a mixture of these templates are to be in a sequence of screens where you can navigate backwards or forwards, I need to be able to sequence them, I can only think of adding a page_number column. I also would like to re-order them and delete them as necessary using the page_number column.
I was planning to do all this in a web application without the need for a standard folder/web page structure, like a small CMS system.
option 1,
I can create one large table with many columns, lot's of which will be empty, over half with each row. Is this bad?
option 2,
I could create many tables using only the relevant template columns required.
The problem I see with this, is the headache of repopulating a column in each table when I delete a row, because I need to re-sequence a column that represents page numbers. Which I reduce if I use one large table.
I've thought of moving page numbers into another table called page_order but I cannot think of a way to maintain an effective relationship between the other tables if I make changes.
I'm yet to figure out how to re-sequence a column in a database when a row is deleted. Surely this is a common problem!?
Thanks for taking the time to help!
Have one table that contains one row per template. It might look like:
id (INT, auto-increment)
page_order (INT, unique key here, so pages cannot have the same number)
field1 (STRING, name of the text field)
value1 (STRING, contents of the text field)
field2
value2
Then you have to decide the maximum fields that any page can have (N) and keep adding field/value columns up to N.
The advantage of this is you have one table that isn't sparsely populated (as long as the templates have about the same number of fields, even if the names of those fields are different).
If you want to make an improvement to his (maybe not necessary for a small amount of data) you could change field to an INT id and connect it to a lookup table that contains (field_id, field_name).
I know this has been asked before..sort of. And that's why I'm posting. Basically I'm building a report in Crystal that relies, to keep this simple, at least 3 tables.
Table A is inner joined to table B by a unique ID. Table B has a child table that may or may not have data related to this unqiue ID.
As a general example table A is a customer table, table B is a product table and the child table is contains the product number. All customers have a product, but not all customers have product number in the child table. I hope I've explained that simply enough.
My issue is sort of between Crytal and Access and how to query this. When I'm writing behind something in VB it's easy enough to write and execute a query and display the result in the desired manner. However I can't seem to get my query straight... I either end up with a report with cartesian product as the resultset, which displays ok...except that even with the few records I have ends up being about 30k pages..or I end up with a blank dataset because the child table does not have corrisponding data to B.
Using outter joins I've managed to get my results within some amount of reason but not acceptable to a real world report. I'm sure this issue has come up but I can't seem to find any suitable answers and to be honest I'm not even sure what questions to ask being a Crystal n00b.
What I'm really after is the data from Table A, the data from Table B and children tables. While they are logically linked and can be linked with the ID field, it isn't necessary I don't think because I am taking a parameter value for the report of the ID field. And once the tables are filtered, no other action needs to be taken except to dump them back on the report.
So can anybody point me in the right direction? Can I set up individual datasoruces (unrelated) based perhaps in a seperate section? Should I build a tree of queries and logic in my DB to get what I need out? I've been racking my brain and can't seem to find the right solution, any and all advice is apreciated and if I can clarify anything or answer any questions I will.
Thanks in advance.
As per requested below:
Section1
ID fname lname
01 john smith
Section2
ID notifiedDate notifiedTime
01 10/10/2012 12:35PM
S2childAdmin
ID noteName
01 jane doe
This data is logically related and can be related in the DB. However it is not necessary as long as the ID parameter is passed to each table. Querying Section1 inner joined with Section2 works fine. But any other arrangements result in more rows than required and I end up with a report many times duplicated. What I really need is something like Section1 joined with Section2 and S2childAdmin as a freely availble table. Otherwise it multiplies my data or results in a null recordset (because it can return 0 rows)
I think this should help point you in the right direction, though it has been 5 years or so since I did heavy Crystal Reports work.
One option might be to join everything using Outer Joins like you stated you were, then use a Crystal Report 'group' on the Table A ID, with a group based upon Table B ID inside of that. So you would, in the actual 'Detail' area put your table C details if there were any, and then use the Group header/footer for Table A and Table B to show data specific to those objects.
Another possible solution that may fall short of your requirements but might get you thinking in another way, is to create your main report and in it, display the fields from table A. Then below those fields include a sub-report and pass in the unique ID from Table A. You will then have a query inside of the subreport that finds all of the Table B records with that Table A.ID value and displays their details.
At this point you run into a weakness of Crystal Reports (at least as of the last version I used) in that you cannot have a subreport inside of a subreport.
I am new to Asp.Net, MVC3, Linq, and everything else related to it. I'm very used to PHP and ColdFusion so pardon my ignorance! Essentially what I am trying to do is re-create the situation in ColdFusion where I can perform the equivalent of a cfoutput's group attribute. I'm so used to just calling a stored procedure and then doing
<cfoutput group="id">
and then another inner cfoutput for any columns that have non-distinct data. Works like a charm! Not so much in Asp.Net.
I would like to stay with using my stored procedure, which is returning a join from two tables with a one-to-many relationship. For example's sake let's say I have 3 columns: a full name, a title, and a graduation year. The graduation year is the column from the joined table, so my result from the stored procedure looks like this:
Jim Professor 2005
Jim Professor 2008
Jim Professor 2011
I am sending this to the View. I am assuming it's the View's job to then group the data based on one of the columns (probably the full name). I want to output an HTML table with 3 columns and in this situation I would have ONE row:
Jim Professor 2005, 2008, 2011
I have googled tons of examples that use this thing called a group key. This does not seem to help me because I'm not interested in just outputting one value "Jim" (or whatever the grouped value is), I need both "Jim" and "Professor" values to be output for each row. My thinking is I would need 2 foreach loops, the outer loop displaying the fullname and title and the inner loop going through all possible matches for the graduation years. I cannot seem to get the graduation years in a group, especially with this IGrouping syntax. The key can only store one value and I need every value on that row, I only really need one or two values to be iterated over. Should I try and create a custom view model after I perform a secondary linq grouping and then send that to a strongly typed view?
EDIT:
Ok, I have code that works but it seems very inefficient as I basically have to re-define all of the columns/values that I have from my stored procedure. It almost makes me want to forget stored procedures and just use LINQ for everything. It seems what I was asking for is a kind of "group on multiple columns" and link helped immensely.
var records = db.getRecords();
var groups = from r in records
group r by new
{
r.id
}
into row
select new ListVM()
{
id = row.Key.id,
fullname = row.Select(x => x.fullname).First(),
title = row.Select(x => x.title).First(),
degrees = row.Select(x => x.degree_name).ToList(),
majors = row.Select(x => x.major_name).ToList()
};
return View(groups);
I of course had to create a ViewModel for this to work. In my view then I can use for loops to iterate over the degrees and majors lists. Is this the best way to do this? I just generally need more than just the group key to display my entire row of information, and only want to iterate over lists once or twice in a 20 column row, as opposed to only displaying the group key once and iterating over everything in most examples I see.
I'm not that big specialist with Linq and MVC, but faced with your problem I would:
Deal with data preparation in controller/model, after being taught that view should be concerned with displaying things only.
I would use knowledge from these topics to solve your particular problem:
a) grouping by multiple columns:
Group By Multiple Columns
b) Concatenation as an aggregate function:
Using LINQ to concatenate strings
c) Using aggregates and grouping by multiple columns
How to write a LINQ query combining group by and aggregates?
Once you have data in your view model, just display it.
I believe I've finally found out how to solve what I was looking for. A "group join" seems to solve my problem with ease. The information I found on this page solved it: http://geekswithblogs.net/WillSmith/archive/2008/05/28/linq-joins-and-groupings.aspx
As I explained in my post a few days before I'm programming an ASP MVC3 multi-language website which should contain facetted search, full text search and a distance search. To realize that I've installed solr 3.3 on a Tomcat 7. I'm also successfully integrated a dataimporthandler.
Now I want to index the data from my relational ms sql database. I read the index structure looks like one table containing all the data of one object. That means if I've got a object like a car my schema catains fields like Branding, Color and so on.
But what about n-m realtions? Does the index "table" have one column for each relation?
And what about multi language items? Should I create one object/row int the index for each language?
And should I save just the id of objects in the index or the whole names?
And last how to index (query) a Object like on the database image? (I read something about dynamic fields and multiplevalue fields but I'm not sure if it is the solution for my problem)
I've a example of a database design I'm talking about attached.
Thanks for all the answers!!!
Update:
The people should be able to have different way to search.
They should have the possibility to search the tbl_text_local.text by full text searching and the miscellaneous are are facettes.
The Result should be a list of objects that match to the search and a list of facetts.
But how should I index the Miscellaneous? Is there a posibility to index them in a form like that:
<cattegory name = "cat1">
<Miscellaneous>
name...
</Miscellaneous>
<Miscellaneous>
...
</Miscellaneous>
<Miscellaneous>
...
</Miscellaneous>
</cattegory>
<cattegory name = "cat2">
<Miscellaneous>
</Miscellaneous>
<Miscellaneous>
</Miscellaneous>
<Miscellaneous>
</Miscellaneous>
</cattegory>
People should have a searchfield like:
Text input (to search the text)
Facettes:
Miscellaneous-Cattegory1
Miscellaneous1 (9)
Miscellaneous2 (39)
Miscellaneous3 (49)
Miscellaneous-Cattegory2
Miscellaneous5 (59)
Miscellaneous6 (69)
Miscellaneous-Cattegory3
Miscellaneous7 (7)
Miscellaneous8 (8)
Miscellaneous-Cattegory4
Miscellaneous9 (19)
There is no single, "best" way to model relationships in Solr. Unlike relational databases, where you design tables by following normalization, in Solr the schema design is very much ad-hoc, a function of the searches you will perform on the index. Ask yourself these questions as guidance:
What are users searching for? What is the "result type"? The schema should be designed around this.
What information do I need to facet?
What information do I need to include in full-text search?
What information do I need to use to sort results?
What information will I search by? I.e. what information will I use to filter search results, and how will I use that information?
What will I process at index-time and what will I process at query-time?
Finally, don't be afraid of duplicating data in the index for specific search purposes.