I have a database in SQL Server containing a column which needs to contain Unicode data (it contains user's addresses from all over the world e.g. القاهرة for Cairo)
This column is an nvarchar column with a collation of database default (Latin1_General_CI_AS), but I've noticed data inserted into it via SQL statements containing non English characters and displays as ?????.
The solution seems to be that I wasn't using the n prefix e.g.
INSERT INTO table (address) VALUES ('القاهرة')
Instead of:
INSERT INTO table (address) VALUES (n'القاهرة')
I was under the impression that Unicode would automatically be converted for nvarchar columns and I didn't need this prefix, but this appears to be incorrect.
The problem is I still have some data in this column which appears as ????? in SQL Server Management Studio and I don't know what it is!
Is the data still there but in an incorrect character encoding preventing it from displaying but still salvageable (and if so how can I recover it?), or is it gone for good?
Thanks,
Tom
To find out what SQL Server really stores, use
SELECT CONVERT(VARBINARY(MAX), 'some text')
I just tried this with umlauted characters and Arabic (copied from Wikipedia, I have no idea) both as plain strings and as N'' Unicode strings.
The results are that Arabic non-Unicode strings really end up as question marks (0x3F) in the conversion to VARCHAR.
SSMS sometimes won't display all characters, I just tried what you had and it worked for me, copy and paste it into Word and it might display it corectly
Usually if SSMS can't display it it should be boxes not ?
Try to write a small client that will retrieve these data to a file or web page. Check ALL your code if there are no other inserts or updates that might convertthe data to varchar before storing them in tables.
Related
My source SQL database contains Arabic characters and the column is an Xml data type. I am trying to get the data flown from source sql to destination sql db. However, when the data flow happens, the column which contains Arabic characters turns into gibberish (unrecognizable characters - not question marks).
How do I transition data correct from the source table to destination table. I have tried using Collate Arabic_CI_AI_KS_WS and used data conversion to add NTEXT and it's still not working.
Appreciate any leads to the direction in resolving this issue.
Thank you
I have a client who inserted some Arabic text into SQL Server database column. Now the text displays as ????? only.
I know that this is related to collation and that he should have modified the collation of SQL Server before entering his data. Also I know that he should have used nVarchar, instead of Varchar in his column.
How can I retrieve the data entered in his column or convert it into Arabic from ???? since the data is already entered and we need to convert it.
Thanks in advance.
Here are some basic rules which you may want to keep in mind. While storing Unicode data, the column must be of Unicode data type (nchar, nvarchar, ntext). Another rule is that the value must be prefixed with N while insertion like the below.
INSERT INTO TBL_LANG VALUES ('English',N'I am American')
INSERT INTO TBL_LANG VALUES ('Tamil',N'நான் தமிழன்')
If the data inserted in the correct manner, then you will get the correct response.
As well have a look at the link.
Convert “???? ??????” in to arabic language
I have a column which was set to Varchar and the database set to SQL_Latin1_General_CP1_CI_AS.
When a user entered their name into our web front end and save the data, it was not saving accented characters correctly.
The web user was entering the following, "Béala" but this was being saved on the database as the following, "Béala".
I believe that changing the column from Varchar to NVarchar should prevent this from happening going forward(?), however, I have two questions.
1) How do I perform a select on the existing data in the column and display it correctly?
select CONVERT(NVARCHAR(100),strAddress1) from [dbo].[tblCustomer]
This still shows the data incorrectly.
2) How do I update the data in the column once converted to NVarchar to save the accented characters correctly?
Many thanks,
Ray.
The only idea that came to my mind is that you have to prepare an update that will fool this badly loaded data, i.e. a sign
'é' will always match exactly one character (in this case 'é'), you have to catch all special characters and this
as have been changed (just a simple update with cases and replace). Of course, the first column must be of the nvarchar type.
It solves the problem 1 and 2 (the data will be correct in the table, the data will be displayed correctly, I described the update above)
Here is way to get it in normal characters scheme.
select 'Réunion', cast('Réunion' as varchar(100)) COLLATE SQL_Latin1_General_CP1253_CI_AI
Moreover to check all possible collations in SQL Server you can try this query
SELECT name, description
FROM sys.fn_helpcollations();
I have a database imported that contains Arabic characters but are displayed as question marks. Through some searching I found that the column data types should be nvarchar to support unicode (they were varchar). I changed one of the columns that contains those characters to nvarchar but the data is still displayed as "??". How can I change the existing values to become unicode and display correctly?
You cannot just simply change the datatype to nvarchar - that won't bring back the data since it's already been "destroyed" by having been converted to a non-Unicode format.
You need to use nvarchar and then you need to insert (or update) the data in such a way that doesn't convert it back to ANSI codes.
If you use T-SQL to insert that Unicode code, make sure to use the N'...' prefix:
INSERT INTO dbo.YourTable(NvarcharCol)
VALUES (N'nvarchar-value')
From a front-end language like C# or PHP or Ruby, make sure to use Unicode strings - .NET (C# and VB.NET) does that automatically. When using queries with parameters, make sure to specify Unicode string types for those relevant parameters.
You need different collation.
Read more here: https://msdn.microsoft.com/en-us/library/ms143508.aspx
Currently, I am in the process of updating all of our Delphi 2007 code base to Delphi XE2. The biggest consideration is the ANSI to Unicode conversion, which we've dealt with by re-defining all base types (char/string) to ANSI types (ansichar/ansistring). This has worked in many of our programs, until I started working with the database.
The problem started when I converted a program that stores information read from a file into an SQL Server 2008 database. Suddenly simple queries that used a string to locate data would fail, such as:
SELECT id FROM table WHERE name = 'something'
The name field is a varchar. I found that I was able to complete the query successfully by prefixing the string name with an N. I was under the impression that varchar could only store ANSI characters, but it appears to be storing Unicode?
Some more information: the name field in Delphi is string[13], but I've tried dropping the [13]. The database collation is SQL_Latin1_General_CP1_CI_AS. We use ADO to interface with the database. The connection information is stored in the ODBC Administrator.
NOTE: I've solved my actual problem thanks to a bit of direction from Panagiotis. The name we read from our map file is an array[1..24] of AnsiChar. This value was being implicitly converted to string[13], which was including null characters. So a name with 5 characters was really being stored as the 5 characters + 8 null characters in the database.
varchar fields do NOT store Unicode characters. They store ASCII values in the codepage specified by the field's collation. SQL Server will try to convert characters to the correct codepage when you try to store Unicode or data from a different codepage. You can disable this feature but the best option is to avoid the whole mess by using nvarchar fields and UnicodeString in your application.
You mention that you changes all character types to ANSI, not UNICODE types in your application. If you want to use UNICODE you should be using a UNICODE type like UnicodeString. Otherwise your values will be converted to ANSI when they are sent to your server. This conversion is done by your code when you create the AnsiString that is sent to the server.
BTW, your select statement stores an ASCII value in the field. You have to prepend the value with N if you want to store it as a unicode value, eg.g
SELECT id FROM table WHERE name = N'something'
Even this will not guarantee that your data will reach the server in a Unicode form. If you store the statement in an AnsiString the entire statement is converted to ANSI before it is sent to the server. If your app makes a wrong conversion, you will end up with mangled data on the server.
The solution is very simple, just use parameterized statements to pass unicode values as unicode parameters and store them in NVarchar fields. It is much faster, avoids all conversion errors and prevents SQL injection attacks.