OracleLob.Value 属性
定义
获取公共语言运行时流值(基础值的等效值)。Gets the common language runtime stream value equivalent of the underlying value.
public:
property System::Object ^ Value { System::Object ^ get(); };
public object Value { get; }
member this.Value : obj
Public ReadOnly Property Value As Object
属性值
对于 Blob,为 Byte[] 类型的数组。For Blob, an array of type Byte[]. 对于 Clob 和 NClob,为 String。For Clob and NClob, a String. 对于 null 数据,则为 DBNull。For null data, DBNull.
例外
对象已关闭或已释放。The object was closed or disposed.
发生了 Oracle 错误。An Oracle error has occurred.
注解
对于 Blob 数据类型, Value 将以类型为的连续数组返回整个基础数据 Byte[] 。For Blob data types, Value returns the entire underlying data as a contiguous array of type Byte[]. 对于 Clob 和 NClob 数据类型, Value 将以数据类型的形式返回所有数据 String 。For Clob and NClob data types, Value returns all the data as a String data type. 对于空数据, Value 返回 DBNull 。For null data, Value returns DBNull. 通过比较返回的值,可以区分空数据、空数据和数据。By comparing the returned values, you can distinguish among empty data, null data, and data.
备注
使用 LOB 数据类型的好处是能够在客户端上以区块形式检索大量数据。A benefit of using LOB data types is the capability to retrieve large amounts of data in chunks at the client. 但是,当你使用时,会将 Value 列的所有数据 LOB 作为一个连续块获取,这可能会显著增加应用程序开销。However, when you use Value, you obtain all the data for the LOB column as one contiguous chunk, which can significantly increase application overhead.