This section describes the data types and length limits of the MSSQL

SQL Server provides a system data type set that defines all data types that can be used with SQL Server. The set of data types provided by the system is listed below.

You can define user-defined data types, which are aliases for system-provided data types. For more information about user-defined data types, see SP_addType and Creating User-defined Data Types.

When two expressions with different data types, collations, precision, decimal numbers, or lengths are combined by an operator:

Determine the data type of the resulting value by applying the precedence rules of the data type to the data type of the input expression. For more information, see Prioritization of Data types.

If the result data type is CHAR, VARCHar, TEXT, NCHAR, NVARCHar, or nTEXT, the collation of the result value is determined by the precedence rule of the collation. For more information, see Precedence of collation.

The precision, decimal, and length of the result depend on the precision, decimal, and length of the input expression. For more information, see Precision, Decimal places, and Length.

SQL Server provides data type synonyms for SQL-92 compatibility. For more information, see Synonyms for Data types.

Precise Numbers

The integer

Bigint Integer data (all numbers) from -2^63 (-9223372036854775808) to 2^63-1 (9223372036854775807).

Int Integer data (all numbers) from -2^31 (-2,147,483,648) to 2^ 31-1 (2,147,483,647).

Smallint Specifies the integer data from -2^15 (-32,768) to 2^ 15-1 (32,767).

Tinyint Specifies the integer from 0 to 255.

bit

Bit Integer data of 1 or 0.

A decimal and numeric

Decimal from -10^38 +1 to 10^38 — 1 for fixed precision and decimal number data.

Numeric is functionally equivalent to decimal.

Money and smallmoney

The money data value is between -2^63 (-922,337,203,685,477.5808) and 2^ 63-1 (+922,337,203,685,477.5807), accurate to ten thousandths of a monetary unit.

Smallmoney Currency data values between -214,748.3648 and +214,748.3647, accurate to ten thousandths of a currency unit

The approximate number

Float A float precision number from -1.79E + 308 to 1.79E + 308.

Real a floating point precision number from -3.40E + 38 to 3.40e + 38.

Datetime and smalldatetime

Datetime Date and time data from January 1, 1753 to December 31, 9999, accurate to three hundredths of a second (or 3.33 milliseconds).

Smalldatetime Date and time data from January 1, 1900 to June 6, 2079, accurate to the minute.

string

Char Fixed-length non-Unicode character data with a maximum length of 8,000 characters.

Varchar Non-Unicode data of variable length, up to 8,000 characters.

Text Non-Unicode data of variable length, maximum length 2^ 31-1 (2,147,483,647) characters.

Unicode string

Nchar Fixed-length Unicode data with a maximum length of 4,000 characters.

Nvarchar Variable-length Unicode data with a maximum length of 4,000 characters. Sysname is the user-defined data type provided by the system. It is equivalent to nvARCHar (128) in function and is used to reference database object names.

Ntext Variable-length Unicode data with a maximum length of 2^ 30-1 (1,073,741,823) characters.

Binary string

Binary FIXED-length binary data, with a maximum length of 8,000 bytes.

Varbinary A variable length of binary data with a maximum length of 8,000 bytes.

Image Variable length binary data with a maximum length of 2^ 31-1 (2,147,483,647) bytes.

Other data types

Cursor A reference to a cursor.

sql_variant

A data type that stores values of the various data types supported by SQL Server (except text, NTEXT, TIMESTAMP, and SQL_VARIANT).

A special data type that stores a result set for later processing.

A unique number of database scope that is updated each time a row is updated.

Globally unique identifier (GUID).