编辑

通过

IMetaDataTables::GetColumnInfo Method

Gets data about the specified column in the specified table.

Syntax

HRESULT GetColumnInfo (
    [in]  ULONG        ixTbl,
    [in]  ULONG        ixCol,
    [out] ULONG        *poCol,
    [out] ULONG        *pcbCol,
    [out] ULONG        *pType,
    [out] const char   **ppName
);

Parameters

=======

ixTbl [in] The index of the desired table.

ixCol [in] The index of the desired column.

poCol [out] A pointer to the offset of the column in the row.

pcbCol [out] A pointer to the size, in bytes, of the column.

pType [out] A pointer to the type of the values in the column.

ppName [out] A pointer to a pointer to the column name.

Remarks

The returned column type falls within a range of values:

pType Description Helper function
0..iRidMax
(0..63)		 Rid IsRidType
IsRidOrToken
iCodedToken..iCodedTokenMax
(64..95)		 Coded token IsCodedTokenType
IsRidOrToken
iSHORT (96) Int16 IsFixedType
iUSHORT (97) UInt16 IsFixedType
iLONG (98) Int32 IsFixedType
iULONG (99) UInt32 IsFixedType
iBYTE (100) Byte IsFixedType
iSTRING (101) String IsHeapType
iGUID (102) Guid IsHeapType
iBLOB (103) Blob IsHeapType

Values that are stored in the heap (that is, IsHeapType == true) can be read using:

  • iSTRING: IMetadataTables.GetString
  • iGUID: IMetadataTables.GetGUID
  • iBLOB: IMetadataTables.GetBlob

Important

To use the constants defined in the table above, include the directive #define _DEFINE_META_DATA_META_CONSTANTS provided by the cor.h header file.

Requirements

Platforms: See .NET supported operating systems.

Header: Cor.h

Library: CorGuids.lib

See also