I'm using this code to store korean string in my database:
Dim username As String = Request.QueryString.Get("Some Korean String")
Using dg As New DataContext()
Dim newfriend As New FriendsTable With {.AskingUser = User.Identity.Name, .BeingAskedUser = username, .Pending = True}
dg.FriendsTables.InsertOnSubmit(newfriend)
dg.SubmitChanges()
end using
Checking my database, the username stored is a string"????"...
anybody got an idea how this happened or any workarounds?
What is your database collation? Are you able to store Korean strings with any other data access technology? What is the type of the username column, and is it accurately mapped in LINQ to SQL?
I suspect that something in the database isn't set up correctly to allow full Unicode. I very much doubt that this has anything to do with LINQ itself.
The other thing to check is that you're actually getting the right data in the first place. There are often several places where things can go wrong - you need to validate each place separately to see where the data is being corrupted. I have a short article on this which you may find helpful.
It sounds like you are storing Korean text in a varchar/text column which is not using a Korean collation. Thea easiest fix is to change the column type to nvarchar/ntext.
The nchar column types store Unicode data, whereas the char and varchar types store single byte characters in the specified collation.
Related
I have column in my database that stores BLOB.
I want to run a query to check if specific byte array value is present in the table.
The value is b'\xf4\x8f\xc6{\xc2mH(\x97\x9c\x83hkE\x8b\x95' (python bytes).
I tried to run this query:
SELECT * from received_message
WHERE "EphemeralID"
LIKE HEX('\xf4\x8f\xc6{\xc2mH(\x97\x9c\x83hkE\x8b\x95');
But I get 0 results though I 100% sure that I store this value in the database.
Is there something wrong with my query?
Your search string is a bit weird-- you appear to have some complex things in there like { and (. Maybe you should search through the blob the way it is stored instead?
From the Sqlite documentation:
BLOB literals are string literals containing hexadecimal data and
preceded by a single "x" or "X" character. Example: X'53514C697465'
So maybe do a like with the ascii representation of the hex value you want? Maybe start with looking for just f48f or F48F if your sqlite stores it upper case.
I am using VBscript, ADO and the SQLite ODBC driver to store and retrieve large strings (~5KB). Storing them works fine, maybe because I am able to specify a size while I bind the parameters of the insert statement. When I try to retrieve those strings, however, I correctly get the first 256 (or 255) characters but the rest seams to come from a random memory area. What am I doing wrong (besides using VBscript and ADO...)?
I'm open to the idea of storing the text as binary data. But the functions I tried, to retrieve it later, didn't work.
getChunk will not work on a record field as noted on msdn, also the field attribute adFldLong states if getChunk can be used on that field.
In some fields you must use the SQL query to retrieve the length of data instead of using attribute actualSize
there is a good example e here http://kek.ksu.ru/eos/ecommerce/masteringasp/18-06.html
I have a huge query string which is around 6000 to 7000 characters, is it possible to encrpyt the string in short?
any alogrithms ?
Usign ASP.NET as the web app.
The short answer is don't do it - it probably indicates you are doing something wrong.
If you have to then I would say the best way would be to store the long query string in a database field and generate a Guid you can store as a key against it.
You can then pass the Guid in the query string and when the page loads you can then retrieve the full details from the database using the key.
The URL accepts 255 character, after that you'll get nothing.
Use what Mr. Kevin mentioned, database storage, or use the context session to store variables you are sending in the query string.
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 my form set in french as well, and it automatically changes the text format to use ','. However When I try to insert my values into the database it says cannot convert nvarchar to decimal?
Worst case, Is there a way I can disable the numbers from changing to use ',' and just use '.' always regardless what language it is?
My working language is vb.net
Thanks,
Robert
If you're passing the values down to the database as nvarchar then you'll need to have converted this to a string using yourDecimalValue.ToString(Globalization.CultureInfo.InvariantCulture) or similar. SQL Server will always expect a decimal to be in 1.23 format - you can imagine the trouble that would result if queries including WHERE myvalue IN (1,25, 1,33, 1,45) were submitted!