Datasheet

Chapter 1: Being Objective: Re-Examining Objects in SQL Server
Data Type Name Class Size in Bytes Nature of the Data
UniqueIdentifier Special
Numeric
(binary)
16 Special Globally Unique Identifier
(GUID). Is guaranteed to be unique across
space and time.
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
ˆ
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 are not 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
ˆ
31 bytes of
data).
Ntext Unicode Varies Like the Text data type, this is legacy
support only — in this case, use
nvarchar(max) . Variable-length Unicode
character data.
Binary Binary Varies Fixed-length binary data with a
maximum length of 8,000 bytes.
VarBinary Binary Varies Variable-length binary data with a
maximum specified length of 8,000 bytes,
but you can use the ‘‘max’’ keyword to
indicate it as essentially a LOB field (up
to 2
ˆ
31 bytes of data).
Image Binary Varies Legacy support only as of SQL Server
2005. Use
varbinary(max) instead!
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