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AlterDataType Method

未來的 Microsoft SQL Server 版本將移除這項功能。請避免在新的開發工作中使用這項功能,並規劃修改目前使用這項功能的應用程式。

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

語法

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);

備註

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.

[!附註]

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:

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參考