Datasheet

Data Type Size in

Name Class Bytes Nature of the Data

DateTime Date/Time 8 Date and time data from January 1, 1753, to

December 31, 9999, with an accuracy of three-

hundredths of a second.

SmallDate Date/Time 4 Date and time data from January 1, 1900, to

Time June 6, 2079, with an accuracy of one minute.

Cursor Special 1 Pointer to a cursor. While the pointer takes up

Numeric only a byte, keep in mind that the result set

that makes up the actual cursor also takes up

memory —exactly how much will vary depend-

ing on the result set.

Timestamp/ Special 8 Special value that is unique within a given

rowversion Numeric database. Value is set by the database itself

(binary) automatically every time the record is inserted or

updated, even though the timestamp column

wasn’t referred to by the

UPDATE statement.

(You’re actually not allowed to update the time-

stamp field directly.)

Unique Special 16 Special Globally Unique Identifier (GUID). Is

Identifier Numeric guaranteed to be unique across space and time.

(binary)

Char Character Varies Fixed-length character data. Values shorter than

the set length are padded with spaces to the set

length. Data is non-Unicode. Maximum specified

length is 8,000 characters.

VarChar Character Varies Variable-length character data. Values are

not padded with spaces. Data is non-Unicode.

Maximum specified length is 8,000 characters,

but you can use the

max keyword to indicate it as

essentially a very large character field (up to 2^31

bytes of data).

Text Character Varies Legacy support as of SQL Server 2005. Use

varchar(max) instead.

NChar Unicode Varies Fixed-length Unicode character data. Values

shorter than the set length are padded with spaces.

Maximum specified length is 4,000 characters.

NVarChar Unicode Varies Variable-length Unicode character data. Values

aren’t padded. Maximum specified length is 4,000

characters, but you can use the

max keyword to

indicate it as essentially a very large character

field (up to 2^31 bytes of data).

Chapter 1

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