Sql – database physical storage for character type

characterencodingsql serverstorage

For SQL Server 2005/2008, after some self-study, I am not sure whether my understanding about how character data type is physically stored is correct. Please help to review and comment. Here is my understanding, please review and feel free to correct me.

when using unicode character type (e.g. nvarchar), underlying character are stored in UCS-2 encoding (i.e. character is stored physically in the form of related UCS-2 defined bit sequences for the character). Collation defines comparison and sorting, no codepage in this situation;
when using non-unicode character type (e.g. varchar), underlying character are stored physically as bits defined in related code page defined by collation. So in this case, collation defines not only comparison/sorting, but also which codepage (character, bit value represents the character, and using the same bit value to store the character in database physical storage).

thanks in advance,
George

Best Answer

I think you are wright ,see the link for further info http://www.sql-server-helper.com/faq/data-types-p01.aspx

Related Solutions

Sql-server – How to get list of all tables in a database using TSQL

SQL Server 2000, 2005, 2008, 2012, 2014, 2016, 2017 or 2019:

SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE='BASE TABLE'

To show only tables from a particular database

SELECT TABLE_NAME 
FROM [<DATABASE_NAME>].INFORMATION_SCHEMA.TABLES 
WHERE TABLE_TYPE = 'BASE TABLE'

Or,

SELECT TABLE_NAME 
FROM INFORMATION_SCHEMA.TABLES 
WHERE TABLE_TYPE = 'BASE TABLE' 
    AND TABLE_CATALOG='dbName' --(for MySql, use: TABLE_SCHEMA='dbName' )

PS: For SQL Server 2000:

SELECT * FROM sysobjects WHERE xtype='U'

Base 64 encoding used for

When you have some binary data that you want to ship across a network, you generally don't do it by just streaming the bits and bytes over the wire in a raw format. Why? because some media are made for streaming text. You never know -- some protocols may interpret your binary data as control characters (like a modem), or your binary data could be screwed up because the underlying protocol might think that you've entered a special character combination (like how FTP translates line endings).

So to get around this, people encode the binary data into characters. Base64 is one of these types of encodings.

Why 64?
Because you can generally rely on the same 64 characters being present in many character sets, and you can be reasonably confident that your data's going to end up on the other side of the wire uncorrupted.

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Related Solutions

Sql-server – How to get list of all tables in a database using TSQL

Base 64 encoding used for

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