I got a little surprised as I was able to store an Ukrainian string in a varchar column .
My table is:
create table delete_collation
(
text1 varchar(100) collate SQL_Ukrainian_CP1251_CI_AS
)
and using this query I am able to insert:
insert into delete_collation
values(N'використовується для вирішення квитки')
but when I am removing 'N' it is showing ?????? in the select statement.
Is it okay or am I missing something in understanding unicode and non-unicode with collate?
From MSDN:
Prefix Unicode character string constants with the letter N. Without
the N prefix, the string is converted to the default code page of the
database. This default code page may not recognize certain characters.
UPDATE:
Please see a similar questions::
What is the meaning of the prefix N in T-SQL statements?
Cyrillic symbols in SQL code are not correctly after insert
sql server 2012 express do not understand Russian letters
To expand on MegaTron's answer:
Using collate SQL_Ukrainian_CP1251_CI_AS, SQL server is able to store ukrainian characters in a varchar column by using CodePage 1251.
However, when you specify a string without the N prefix, that string will be converted to the default non-unicode codepage before it is sent to the database, and that is why you see ??????.
So it is completely fine to use varchar and collate as you do, but you must always include the N prefix when sending strings to the database, to avoid the intermediate conversion to default (non-ukrainian) codepage.
Related
I am having a codepage unicode/non unicode problem and need expertise to understand it.
In SSIS I am reading data in from a UTF8 encoded text file. The datatypes are all DT_WSTR (unicode string). The destination is NVARCHAR which is also unicode.
Non standard characters such as Ú are not being encoded correctly )appearing as a black box question mark).
If the character appears correctly in the input file, the source is set to DT_WSTR & the destination is nvarchar, why is the character not rendering correctly?
I have tried setting the codepage of the source column to 65001, but in SSIS its only possible to change the codepage on a STR (non unicode) type.
Id appreciate any help in understanding why all unicode fields still cant store a unicode value correctly.
Update from the OP comments
It seems my output is ok if i use Unicode types end to end (input is DT_WSTR, destination column is nvarchar & when extracting again to text, output column is DW_WSTR. The only issue is sql server management studio, which does not seem to be able to render unicode characters correctly in the results of a query, when setting output to grid or text. this is a red herring and the process overall works without issue if this is ignored
Trying to figure out the issue
There is not problem importing unicode characters from flat files to SQL Server destination, the only thing you have to do is the set the flat file encoding as unicode, and the result columns must be NVARCHAR. Based on your question, it looks like you have met the requirements so i can say that:
Unicode Character are imported successfully to SQL Server, but for some reasons SQL Server Management Studio cannot show unicode characters in a grid Results, to check that data is imported correctly, change change the result view to Result To Text.
GoTo Tools >> Options >> Query Results >> Results To Text
In the second reference link i provided they mentioned that:
If you use SSMS for your queries, change to output type from "Grid" to "Text", because depending on the font the grid can't show unicode.
Or you can try to change the Grid Results font, (on my machine, i use Tahoma font and it shows unicode characters normally)
Experiments
You can perform the following test (taken from the links below)
SET NOCOUNT ON;
CREATE TABLE #test
( id int IDENTITY(1, 2) NOT NULL Primary KEY
,Uni nvarchar(20) NULL);
INSERT INTO #test (Uni) VALUES (N'DE: äöüßÖÜÄ');
INSERT INTO #test (Uni) VALUES (N'PL: śćźłę');
INSERT INTO #test (Uni) VALUES (N'JAP: 言も言わずに');
INSERT INTO #test (Uni) VALUES (N'CHN: 玉王瓜瓦甘生用田由疋');
SELECT * FROM #test;
GO
DROP TABLE #test;
Try the following query using Result as Grid and Result as Text options.
References
SQL Server 2012 not showing unicode character in results
sql server 2008 not showing and inserting unicode characters!
Import UTF-8 Unicode Special Characters with SQL Server Integration Services
Microsoft SQL Server Management Studio - query result as text
Below is my code sample.
DECLARE #a TABLE (a VARCHAR(20));
INSERT #a
(a)
VALUES ('中');
SELECT *
FROM #a;
I'm using SQL Server Management Studio to run it. My question is, why I can insert non-ascii characters into VARCHAR column and correctly get it back? As I understand, VARCHAR type is only for ascii characters and the NVARCHAR is for unicode characters. Anyone can help to explain it please? I'm on Windows 7 with SQL Server 2014 developer edition.
The codepage used to store the varchar data varies by DB collation.
https://msdn.microsoft.com/en-us/library/ms189617.aspx
Varchar is 8 bits, so you may have a different collation, or you may have gotten lucky on where your character falls on the code set
You can find the ASCII and Extended ASCII characters below.
ASCII
Extended ASCII
I don't believe '中' is an ASCII character.
www.asciitable.com
[THIS IS NOT A QUESTION ABOUT NVARCHAR OR HOW TO STORE CHINESE CHARACTER]
SQL Server 2008 Express
Database collation is SQL_Latin1_General_CP1_CI_AS
create table sample1(val varchar(2))
insert into sample1 values(N'中文')
I know these Chinese characters would become junk characters.
I know I can use nvarchar to overcome all problem.
What I don't know is: why there isn't "string too long" error when I run the insert statement?
N prefix means that client will encode the string using UNICODE.
2 Chinese characters will become 4 bytes.
varchar(2) can only contain 2 bytes.
Why people down vote this question? really?
An implied cast takes place. This would work if "val" was created as nvarchar(2).
More explanation to #marc_s answer.
The character N'中文' will be converted to varchar with the collation SQL_Latin1_General_CP1_CI_AS. Since there is no such character in the code page, it will converted to not defined, and 0x3f3f in the end. 0x3f is the question mark, so there will be two question marks in this case and it won't exceed the column length.
Try to use NVARCHAR(...), NCHAR(...) datatypes -
CREATE TABLE dbo.sample1
(
val NVARCHAR(4)
)
INSERT INTO dbo.sample1
SELECT N'中文'
I have table with two varchar columns first_name and last_name.
Now I need to convert these columns to nvarchar in order to support UTF-8.
I choose nvarchar datatype in SSMS for these columns and when I try to enter some UTF-8 data, my symbols converts to question marks. For example, if I input йцукен (Ukrainian) it will be converted to ??????.
What is the problem and how to fix it?
Thanks.
When you want to insert nvarchar literals into the database table, you must use the N'..' prefix.
So use
INSERT INTO dbo.YourTable(First_Name)
VALUES(N'йцукен')
so that this string will be treated as a unicode string
If you're not using the N'..' notation, you're really inserting a non-unicode string literal - and this will cause these conversions to ?
I need to insert chinese characters in my database but it always show ???? ..
Example:
Insert this record.
微波室外单元-Apple
Then it became ???
Result:
??????-Apple
I really Need Help...thanks in regard.
I am using MSSQL Server 2008
Make sure you specify a unicode string with a capital N when you insert like:
INSERT INTO Table1 (Col1) SELECT N'微波室外单元-Apple' AS [Col1]
and that Table1 (Col1) is an NVARCHAR data type.
Make sure the column you're inserting to is nchar, nvarchar, or ntext. If you insert a Unicode string into an ANSI column, you really will get question marks in the data.
Also, be careful to check that when you pull the data back out you're not just seeing a client display problem but are actually getting the question marks back:
SELECT Unicode(YourColumn), YourColumn FROM YourTable
Note that the Unicode function returns the code of only the first character in the string.
Once you've determined whether the column is really storing the data correctly, post back and we'll help you more.
Try adding the appropriate languages to your Windows locale setings. you'll have to make sure your development machine is set to display Non-Unicode characters in the appropriate language.
And ofcourse u need to use NVarchar for foreign language feilds
Make sure that you have set an encoding for the database to one that supports these characters. UTF-8 is the de facto encoding as it's ASCII compatible but supports all 1114111 Unicode code points.
SELECT 'UPDATE table SET msg=UNISTR('''||ASCIISTR(msg)||''') WHERE id='''||id||''' FROM table WHERE id= '123344556' ;