I am trying to create an application for work. The app will be used internally and should allow us to assign some barcode numbers to our product SKUs. I am using Visual Studio / Basic 2010 Express to build this as my very limited and beginners experience is with VS 2010 Express.
I'll give a bit of information about how I see this application working and then I'll get on with my actual question:
I see the app allowing us to create a new Product in the database by a user entering the SKU and description of the product and then the app will assign this product the next available base number for the barcode and from there the app will (if required) generate the correct EAN13 and GTIN14 barcodes and store them against that SKU.
As a company we have a large range of barcode numbers we can use and we have split this large range up so that the first 50,000 (for example) are for our EAN13 codes, the next 50K are for our GTIN14 codes for Inner Cartons and the remaining 50K are for Master Cartons.
So in order to achieve this I have my Product table which contains the fields 'SKU', 'Description' and 'BarcodeBase'. I have managed to set the BarcodeBase field as unique and I am attempting to use AutoIncrement(Seed & Step) to make sure that this assigns the product a base barcode (before I calculate the check digit) that falls within the EAN13 range as described above...
So finally my question is: Is there a way I can put an upper limit on AutoIncrement so that on the off chance, way way in the future, the base barcode number will not overflow into the next range?
I've been googling unsuccessfully for an answer and I am only coming across things which talk about the data type of the field having a limit. For example the upper limit of an Int32 type. Through my searches I have become vaguely aware of the 'Expression' property of the field and also the possibility of coding a partial class - but I don't know if that is the right direction to go in or if there is something much simpler that I am overlooking / have not found.
I would really appreciate any help!
Edit: As per GrandMasterFlush's comment - I have added a local database to my VS project. So I think I am using a SQL Server Compact 3.5 db.
Use a CHECK constraint, e.g.:
ALTER TABLE dbo.Product ADD CONSTRAINT ...
CHECK (BarcodeBase BETWEEN 1 AND 50000);
I suggest you do not make BarcodeBase an IDENTITY column in the Product table (IDENTITY is the feature that you are referring to as "autoincrement"). IDENTITY is really designed for surrogate key use only and isn't ideal for meaningful business data. You can't update an IDENTITY column, it isn't necessarily sequential, may have gaps in the number sequence and you also only get to use one IDENTITY column per table. Instead of using IDENTITY in the Product table you can generate the sequence elsewhere, for example by incrementing a single value stored in a single row table.
Related
I am trying to auto increment data, which is not Id, I have used Sql Identity on Id so can't use it anymore. I tried sql sequence to bind data column and it works if I add information from sql via script but it does not work on adding from visual studio. I tried to [DatabaseGenerated(DatabaseGeneratedOption.Computed)] but it does not work too. I have been searching this topic for 2 days in web but can't find any solution
You can use SQL Sequences for this. According to the documentation by Microsoft
A sequence is a user-defined schema bound object that generates a sequence of numeric values according to the specification with which the sequence was created. The sequence of numeric values is generated in an ascending or descending order at a defined interval and can be configured to restart (cycle) when exhausted. Sequences, unlike identity columns, are not associated with specific tables. Applications refer to a sequence object to retrieve its next value. The relationship between sequences and tables is controlled by the application. User applications can reference a sequence object and coordinate the values across multiple rows and tables.
You can create a sequence using the syntax below:
CREATE SEQUENCE OrderNumber
START WITH 1
INCREMENT BY 1 ;
GO
To check how it can be used in MVC, please check this post.
Hope this helps!
I'm new to Sharepoint 2010 with what I would call a highschool freshman level of coding experience, though I can generally stumble and tinker my way through. I don't currently have access to Sharepoint designer, but from the searching I've done so far, it may required. Still I'm hoping to find an OOTB solution to the problem below.
I have been tasked with building a incident resolution tracking sheet on Sharepoint. My boss is very concerned with being audited by legal, and has some very specific requirements about required information. Column A contains a drop down list of 5 choices that indicate the Final Solution. Column B Contains a drop down list with 4 choices that indicate the Initial Problem. Based on The selections in A and B, different Columns in C-X are required to be blank, not blank, or contain specific entries. The only way I can find to do this is to create a list validation containing a nested if for each combination of A and B resulting in 20 nested ifs. However sharepoint is limited to 7 nested ifs, so I'm looking for any possible solutions.
*This List will primarily be accessed in Datasheet view, so "HTML in calculated column" type solutions are not viable.
You can use calculated columns to break up the validation formula into more manageable chunks.
Let's start with a simple example.
Condition 1: If the initial problem was that the user's computer was too slow and the final solution was restarting the computer, you need to fill in the [C] column.
Condition 2: If the initial problem was that the user was on fire and the final solution was dousing them with water, you need to fill in the [D] column.
You could perform that list validation all in one formula, as below:
=IF(
AND([A]="Restarted Computer",[B]="Computer is slow"),
NOT(ISBLANK([C])),
IF(
AND([A]="Doused with water",[B]="User is on fire"),
NOT(ISBLANK([D]),
TRUE
)
)
But that's long and ugly (especially when you condense it to one line).
Instead, you could add two calculated columns, one for each condition you want to check. For the sake of this example, let's say you add a column called C_is_valid and a column called D_is_valid:
C_is_valid calculated column formula:
=IF(AND([A]="Restarted Computer",[B]="Computer is slow"),NOT(ISBLANK([C])),TRUE)
D_is_valid calculated column formula:
IF(AND([A]="Doused with water",[B]="User is on fire"),NOT(ISBLANK([D]),TRUE)
Updated validation formula:
=AND([C_is_valid],[D_is_valid])
It's easy to see how this can simplify even a very complex set of validation conditions...
=AND(C_is_valid,AND(D_is_valid,AND(E_is_valid,AND(F_is_valid,AND(G_is_valid,AND(H_is_valid,I_is_valid)))))
But even that could be simplified by consolidating some of those AND()s into multiple calculated columns, so that your final validation formula could be as simple as:
=AND([First set of conditions is valid],[Second set of conditions is valid])
So, a company I work at has an older ERP system that uses FoxPro 4 or 5. There is no support for the system, so I am trying to use skills that I don't possess. I'm good with Servers and even networks, but not coding. I have attached links to two similar errors that are occuring to two different users in different departments using different computers. Your help would be appreciated.
FoxPro Error 1
FoxPro Error 2
Well, the problem is exactly what it says on the tin. It looks like the issue is with the field BODY.COST. The field will have a maximum capacity, for example N(12, 2) would allow numbers up to 999999999.99 to be stored in it.
The system is attempting to put a number that is bigger than the defined capacity into this field. You can see it is a GATHER MEMVAR statement in both cases. This statement takes memory variables and updates a database table using them. One of the memory variables has ended up with a bigger number in it than the database field (looks like BODY.COST) that is intended to store it has capacity for.
Beyond that, with no support and no source code you are really limited to looking at what the user is trying to post and seeing if that gives you any clues. Is that the extent of the error dumps or are those just snippets?
The messages are saying that you are trying to store a larger value than the field would accept. This happens with numeric and float fields in Foxpro. In both of the messages, the table was indirectly aliased as "BODY" and the problematic field is "COST".
As a solution, using VFP5 (do not use a later version - there weren't VFP4), you can make all the numeric and float fields to either Currency or Double data type.
Currency has a high certainity and suggested for monetary values (need not be monetary). It is in the range of –922337203685477.5808 to 922337203685477.5807. That range is actually above what a numeric/float field can support.
If you think that is not enough range, than you can use double (something like -10^327 to 10^304 - VFP has a precision of 15 digits, you lose precision beyond that).
I would go with Currency.
We have a database with 2,00,000 vendor in 100 plus category, if someone visit the website we want to allow them to select a category and show them 25 Vendor per page, first we kept order by VendorId but it always use to get first 25, but we removed it, but now in paging it sometime repeat the vendor, is there a way to get random 25 vendor and also keep the paging.
Regards
you can randomize your result but everytime you dot he query, it will create new random list so unless you randomize and save the randomized state in your Code and page over it, it cant be done straightforward way.
refer, SQL Query results pagination with random Order by in SQL Server 2008
I believe this requirement is impossible to implement if a new random order is needed every time, there needs to be good performance and every item should have equal chance to get selected. I believe you should redesign the way your application works.
One possible workaround is to have a couple of columns in a table and fill them with random numbers. When a user requests the list assign the random column to him (stick it in the URL for example). Then do an order by that column and display the results. Randomly switch 4-5 columns to create the appearance of randomness. Update the random numbers in the columns once a day.
just wondering does anyone in here have good idea about generating nice order id?
for example
832-28-394, which show a quite nice and formal order id (rather than just use an database auto increment number like ID=35).
the order id need to look random so it can not be able to guess by user.
e.g. 832-28-395 (shoudnt exist) so there will always some gap between each id.
just like the account number for your bank card?
Cheers
If you are using .NET you can use System.Guid.NewGuid()
The auto-incremented IDs are stored as integer or long integer data. One of the reasons for this is that this format is compact, saving space, including in indexes which are typically inclusive a primary key for use with joins and such.
If you wish to create a nice looking id following a particular format syntax, you'll need to manage the generation of the IDs yourself, and store these in a "regular" column not one that is auto-incremented.
I suggest you keep using "ugly looking" ids, be they auto-incremented or not, and format these value for display purposes only, using whatever format you may desire, including some format that use the values from several columns. Depending on the database system you are using you may be able to declare custom functions, at the level of the database itself, allowing you to obtain the readily formatted value with a simple query (as in
SELECT MakeAFancyId(id_field), some_other_columns, ..
FROM ...
If you cannot use some built-in or custom function at the level of SQL, you'll need to format the value supplied by SQL (an integer of sorts), into the desired format, on the client-side, using the language associated with your UI / presentation framework.
I'd create something where the first eight numbers are loosely in a pattern, and a third quartet looks random but is really a sort of checksum.
So, for example, the first eight digits increment based on the current seconds on the server clock.
The last four could be something like the sum of the first four, plus twice the sum of the second four, which will give either a two or three digit number. The final digit is calculated so that the sum of all 11 digits plus this last one is a multiple of 9.
This is slightly akin to how barcode numbers are verified. You can format the resulting 12 digits any way you want, although it is the first eight that are unique here.
Hash the clock time.
Mod by 100,000 or something.
Format with hyphens.
Check for duplicates. If found, restart.
I would suggest using a autoincrement ID in the database to link tables and as a primary key. Integer fields are always faster than string fields for indexing and well as searching.
You can have the order number field (which is for display) as a different field in the order table which will be used to display. And whenever you are planning to send a URl to a user or display a URL to the user which has order ID (which is a autoincremented number) you can encrypt it with some algorithm.
Both your purpose will be solved.
But I suggest not to make string as primary key. Though you can have a unique constraint on the order number which is going to be displayed.
Hope this helps.
Kalpak Luniya
I would suggest internally you keep the database derived primary key, which is auto-incremented.
For the visible order number, you will probably need a longer length than 8 characters, if you are using this for security.
If you are using Ruby, look at SecureRandom, which will generate sufficiently random strings to accomodate this. For example, you can use SecureRandom.hex(16), and it will give you a 16 digit hex number. I believe it can also give you base 64 strings, which will look weirder but be shorter.
Make sure this is not your only security on an order, as it may not be that hard to find a valid order number within your 8 digit code, especially if some are some sort of checksum.
For security reasons i suggest that you should use Criptographicaly secure random number generator. Think about idea on icreasing User Id length -if you have 1 million users then the probability to gues User ID in first try is 0.01 and 67 tries to increase probability over 0.5