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AlterDataType Method

后续版本的 Microsoft SQL Server 将删除该功能。 请避免在新的开发工作中使用该功能，并着手修改当前还在使用该功能的应用程序。

The AlterDataType method alters the data type of the referenced column.

语法

object.AlterDataType(Datatype, [ Length ] , [ Precision ] , [ Scale ] )

Parts

  • object
    Expression that evaluates to an object in the Applies To list.

  • DataType
    String that specifies the new data type.

  • Length
    Optional long integer that specifies the length of a string data type.

  • Precision
    Optional long integer that specifies the precision of a numeric data type.

  • Scale
    Optional long integer that specifies the scale of a numeric data type.

Prototype (C/C++)

HRESULT AlterDataType(
SQLDMO_LPCSTR DataType, 
long Length,
long Precision,
long Scale);

注释

When using AlterDataType to convert the data type of an existing column to a new data type, the two data types must be compatible. For example, an int data type can be converted to a decimal data type, and a char data type can be converted to an nvarchar data type. However string data types cannot be converted to numeric data types.

注意注意

If an application calls AlterDataType on an instance of SQL Server version 7.0, the constant, SQLDMO_E_SQL80ONLY, and the message "This property or method requires Microsoft SQL Server 2000" are returned.

Applies to:

Column2 Object

请参阅

参考

Datatype Property