The correspondence between SQL Server and data types in C #

Source: Internet
Author: User

corresponding Relationship table
SQL Server http://hovertree.com/menu/sqlserver/ C# Codesmith
Data type Range of values Data type Range of values Null value instead of value Data type
bigint -2^63 (-9,223,372,036,854,775,807) to 2^63-1 (9,223,372,036,854,775,807) Int64 -9,223,372,036,854,775,808; hexadecimal 0x8000000000000000 to 9,223,372,036,854,775,807; hexadecimal 0x7fffffffffffffff Int64.minvalue Int64
Binary A fixed-length n-byte binary data. N must be from 1 to 8,000. The storage space size is n+4 bytes. Byte[] Null Binary
Bit True,false Enum 0,1,-1 (instead of using an enumeration variable) public enum Bitnull {False, True, Null =-1}; -1 Boolean
Char A fixed-length, non-Unicode character data with a length of n bytes. n must be a numeric value between 1 and 8,000. The storage size is n bytes. String Null Ansistringfixedlength
Datetime Store dates from January 1, 1753 to December 31, 9999 (each value requires 8 bytes of storage space) Datetime January 1, 01 00:00:00.0000000 to December 31, 9999 23:59:59.9999999 1753-01-01 0:00:00 Datetime
Decimal From-10^38 +1 to 10^38-1 Decimal -79,228,162,514,264,337,593,543,950,335 to 79,228,162,514,264,337,593,543,950,335 Decimal.minvalue Decimal
Float Floating-point digital data from 1.79E + 308 to 1.79E + 308 Double -1.79769313486232e308 to +1.79769313486232e308 Double.minvalue Double
Image Variable-length binary data is between 0 and 231-1 (2,147,483,647) bytes. Byte[] Null Binary
Int Integer data from -2^31 (-2,147,483,648) to 2^31-1 (2,147,483,647) (all numbers) Int 2,147,483,648 to 2,147,483,647 -2147483648 Int32
Money The currency data value is between -2^63 ( -922,337,203,685,477.5808) and 2^63-1 (+922,337,203,685,477.5807), which is accurate to 10 per thousand of the currency unit. The storage size is 8 bytes. Single -3.402823e38 to +3.402823e38 Single.minvalue Currency
NChar A maximum of 4,000 Unicode characters String Null Stringfixedlength
ntext The maximum length of a variable-length Unicode data is 230-1 (1,073,741,823) characters. The storage size is twice times the number of characters entered (in bytes). String Null String
Numeric When using maximum precision, valid values are from-10^38 +1 to 10^38-1 Decimal -79,228,162,514,264,337,593,543,950,335 to 79,228,162,514,264,337,593,543,950,335 Decimal.minvalue Decimal
nvarchar A variable-length Unicode character data that contains n characters. The value of n must be between 1 and 4,000. String Null String
Real Floating-point numeric data from 3.40E + 38 to 3.40E + 38. The storage size is 4 bytes. Single -3.402823e38 to +3.402823e38 Single.minvalue Single
smalldatetime The date from January 1, 1900 to June 6, 2079 (each value requires 4 bytes of storage space). Datetime January 1, 01 00:00:00.0000000 to December 31, 9999 23:59:59.9999999 1900-01-01 0:00:00 Datetime
smallint Integer data from -2^15 (-32,768) to 2^15-1 (32,767). The storage size is 2 bytes. Int16 -32768 to 32767 Int16.minvalue Int16
SmallMoney The currency data value is between -214,748.3648 and +214.748,3647 and is accurate to 10 per thousand of the currency unit. The storage size is 4 bytes. Single -3.402823e38 to +3.402823e38 Single.minvalue Currency
sql_variant Large data types are not supported in SQL Server 2000 text, ntext, image, timestamp, other types are supported Object Null Object
Text The maximum length of a variable-length non-Unicode data in a server code page is 231-1 (2,147,483,647) characters. When the server code page uses double-byte characters, the storage is still 2,147,483,647 bytes. The storage size may be less than 2,147,483,647 bytes (depending on the string). String Null Ansistring
Timestamp Timestamp This data type shows the automatically generated binary number, ensuring that these numbers are unique in the database. Timestamp is generally used as a mechanism for adding a version stamp to a table row. The storage size is 8 bytes. Byte[] Null Binary
tinyint Integer data from 0 to 255. The storage size is 1 bytes. Byte 0 to 255 Byte.minvalue Byte
uniqueidentifier Stores a 16-byte binary value that uses the same value as the globally unique identifier (GUID). A GUID is a unique binary number, and no two computers in the world will generate duplicate GUID values. GUIDs are primarily used to assign identifiers that must be unique in a network with multiple nodes and multiple computers. Guid Guid.Empty Guid
varbinary N bytes Variable-length binary data. n must be from 1 to 8,000. The size of the storage space is the actual input data length + 4 bytes instead of n bytes. The data entered may be 0 bytes in length. Byte[] Null Binary
varchar Variable-length, non-Unicode character data with a length of n bytes. n must be a numeric value between 1 and 8,000. Storage size is the actual length of bytes of input data, not n bytes. The input data character length can be zero. String

Functions that convert SQL types to C # types

/// <summary>///data types in the database and in C # from what to ask/// </summary>/// <param name= "type" ></param>/// <returns></returns>Private stringChangetocsharptype (stringtype) {    stringReval =string. Empty;Switch(type. ToLower ()) { Case "int": Reval ="Int32"; Break; Case "text": Reval ="String"; Break; Case "bigint": Reval ="Int64"; Break; Case "binary": Reval ="system.byte[]"; Break; Case "bit": Reval ="Boolean"; Break; Case "Char": Reval ="String"; Break; Case "datetime": Reval ="System.DateTime"; Break; Case "decimal": Reval ="System.Decimal"; Break; Case "float": Reval ="System.Double"; Break; Case "Image": Reval ="system.byte[]"; Break; Case " Money": Reval ="System.Decimal"; Break; Case "nchar": Reval ="String"; Break; Case "ntext": Reval ="String"; Break; Case "Numeric": Reval ="System.Decimal"; Break; Case "nvarchar": Reval ="String"; Break; Case "Real": Reval ="System.Single"; Break; Case "smalldatetime": Reval ="System.DateTime"; Break; Case "smallint": Reval ="Int16"; Break; Case "smallmoney": Reval ="System.Decimal"; Break; Case "timestamp": Reval ="System.DateTime"; Break; Case "tinyint": Reval ="System.Byte"; Break; Case "uniqueidentifier": Reval ="System.Guid"; Break; Case "varbinary": Reval ="system.byte[]"; Break; Case "varchar": Reval ="String"; Break; Case "Variant": Reval ="Object"; Break;default: Reval ="String"; Break; } returnReval;}/*how to ask Hovertree.com*/

Recommendation: http://www.cnblogs.com/roucheng/p/netkuangjia.html

The correspondence between SQL Server and data types in C #

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