String Type Conversion During Concatenation in SQL Server

Q

What Happens When Unicode Strings Concatenate with Non-Unicode Strings in SQL Server Transact-SQL?

✍: FYIcenter.com

A

If a Unicode string NVARCHAR is concatenated with a non-Unicode string VARCHAR, SQL Server will implicitly convert the non-Unicode string to Unicode string for concatenation.

DECLARE @regcode VARCHAR(40);
DECLARE @unicode NVARCHAR(40);
SET @regcode = 'Some Unicode characters: '
SET @unicode = NCHAR(9733)+NCHAR(9734)+NCHAR(9792)
   +NCHAR(9794);
SELECT @regcode + @unicode; 
SELECT DATALENGTH(@regcode);
SELECT DATALENGTH(@unicode);
SELECT DATALENGTH(@regcode + @unicode);
Some Unicode characters: ????
25
8
58

Note that the non-Unicode string @regcode has been converted to a Unicode string. The number of bytes of @regcode changed from 25 to 50. With 8 bytes from @unicode, the number of bytes of the concatenated string becomes 58.

⇒ Converting Unicode Strings to Non-Unicode Strings in SQL Server

⇐ Concatenating Two Character Strings in SQL Server

⇑ Character Strings and Binary Strings in SQL Server Transact-SQL

⇑⇑ SQL Server Transact-SQL Tutorials

2017-03-11, 3087🔥, 0💬

Inserting New Line Characters into Strings in SQL Server
How To Insert New Line Characters into Strings in SQL Server Transact-SQL? If you want to break a string into multiple lines, you need to insert new line characters into the string. With some client tools like SQL Server Management Studio, it is not so easy to insert a new line character. One work a... 2022-05-12, 8131🔥, 1💬

ROUND() - Rounding Values to Specific Precisions in SQL Server
How To Round a Numeric Value To a Specific Precision in SQL Server Transact-SQL? Sometimes you need to round a numeric value to a specific precision. For example, you may want to round values in your financial statement to the precision of 1000.00. This can be done by the ROUND() function with the f... 2017-03-11, 7197🔥, 0💬

FLOOR, CEILING, ROUND - Converting Values to Integers in SQL Server
How To Convert Numeric Values to Integers in SQL Server Transact-SQL? Sometimes you need to round a numeric value into an integer. SQL Server 2005 offers you a number of ways to do this: FLOOR(value) - Returning the largest integer less than or equal to the input value. The returning data type is th... 2017-03-22, 6829🔥, 0💬

Converting Unicode Strings to Non-Unicode Strings in SQL Server
How To Convert a Unicode Strings to Non-Unicode Strings in SQL Server Transact-SQL? Since Unicode character set is different than code page based (non-Unicode) character set, converting Unicode strings to non-Unicode strings may result in wrong characters or missing characters. So you should avoid c... 2017-03-07, 6171🔥, 0💬

Concatenating Two Character Strings in SQL Server
How To Concatenate Two Character Strings Together in SQL Server Transact-SQL? Concatenating two character strings together is most commonly used string operation. SQL Server 2005 allows to concatenate two character strings into a single string with the (+) operator. The following tutorial exercise s... 2017-03-11, 6163🔥, 0💬

CHARINDEX() and SUBSTRING() - Locating and Taking Substrings in SQL Server
How To Locate and Take Substrings with CHARINDEX() and SUBSTRING() Functions in SQL Server Transact-SQL? Transact-SQL is not a language designed for manipulating strings, but it does have two simple functions to locate and take substrings: CHARINDEX() and SUBSTRING(). The tutorial exercise below ass... 2017-03-07, 5207🔥, 0💬

Concatenating Two Binary Strings in SQL Server
How To Concatenate Two Binary Strings Together in SQL Server Transact-SQL? SQL Server 2005 allows to concatenate two binary strings into a single string with the (+) operator. The following tutorial exercise shows you some binary string concatenation examples: -- Concatenating two binary string lite... 2017-03-07, 5075🔥, 0💬

Character Strings and Binary Strings in SQL Server Transact-SQL
Where to find answers to frequently asked questions on Character Strings and Binary Strings in SQL Server Transact-SQL? Here is a list of frequently asked questions and their answers compiled by FYIcenter.com DBA team on Character Strings and Binary Strings in SQL Server Transact-SQL. Clear answers ... 2017-03-11, 3333🔥, 0💬

String Type Conversion During Concatenation in SQL Server
What Happens When Unicode Strings Concatenate with Non-Unicode Strings in SQL Server Transact-SQL? If a Unicode string NVARCHAR is concatenated with a non-Unicode string VARCHAR, SQL Server will implicitly convert the non-Unicode string to Unicode string for concatenation. DECLARE @regcode VARCHAR(4... 2017-03-11, 3088🔥, 0💬

All rights in the contents of this web site are reserved by the individual author. fyicenter.com does not guarantee the truthfulness, accuracy, or reliability of any contents.