Bewerken

Delen via

Macros and Global Functions for OLE DB Consumer Templates

  • Artikel

The OLE DB Consumer Templates include the following macros and global functions:

Global Functions

Name Description
AtlTraceErrorRecords Dumps OLE DB Error Record information to the dump device if an error is returned.

Accessor Map Macros

Name Description
BEGIN_ACCESSOR Marks the beginning of an accessor entry.
BEGIN_ACCESSOR_MAP Marks the beginning of the accessor map entries.
END_ACCESSOR Marks the end of an accessor entry.
END_ACCESSOR_MAP Marks the end of the accessor map entries.

Column Map Macros

Name Description
BEGIN_COLUMN_MAP Marks the beginning of the column map entries in the user record class.
BLOB_ENTRY Used to bind a binary large object (BLOB).
BLOB_ENTRY_LENGTH Reports the length of the BLOB data column.
BLOB_ENTRY_LENGTH_STATUS Reports the length and status of the BLOB data column.
BLOB_ENTRY_STATUS Reports the status of the BLOB data column.
BLOB_NAME Used to bind a binary large object by column name.
BLOB_NAME_LENGTH Reports the length of the BLOB data column.
BLOB_NAME_LENGTH_STATUS Reports the length and status of the BLOB data column.
BLOB_NAME_STATUS Reports the status of the BLOB data column.
BOOKMARK_ENTRY Represents a bookmark entry on the rowset. A bookmark entry is a special kind of column entry.
COLUMN_ENTRY Represents a binding to a specific column in the database.
COLUMN_ENTRY_EX Represents a binding to the specific column in the database. Supports type, length, precision, scale, and status parameters.
COLUMN_ENTRY_LENGTH Represents a binding to the specific column in the database. Supports the length variable.
COLUMN_ENTRY_LENGTH_STATUS Represents a binding to the specific column in the database. Supports status and length parameters.
COLUMN_ENTRY_PS Represents a binding to the specific column in the database. Supports precision and scale parameters.
COLUMN_ENTRY_PS_LENGTH Represents a binding to the specific column in the database. Supports the length variable, precision and scale parameters.
COLUMN_ENTRY_PS_LENGTH_STATUS Represents a binding to the specific column in the database. Supports status and length variables, precision and scale parameters.
COLUMN_ENTRY_PS_STATUS Represents a binding to the specific column in the database. Supports the status variable, precision and scale parameters.
COLUMN_ENTRY_STATUS Represents a binding to the specific column in the database. Supports the status variable.
COLUMN_ENTRY_TYPE Represents a binding to a specific column in the database. Supports type parameter.
COLUMN_ENTRY_TYPE_SIZE Represents a binding to the specific column in the database. Supports type and size parameters.
COLUMN_NAME Represents a binding to a specific column in the database by name.
COLUMN_NAME_EX Represents a binding to a specific column in the database by name. Supports specification of data type, size, precision, scale, column length, and column status.
COLUMN_NAME_LENGTH Represents a binding to a specific column in the database by name. Supports specification of column length.
COLUMN_NAME_LENGTH_STATUS Represents a binding to a specific column in the database by name. Supports specification of column length and status.
COLUMN_NAME_PS Represents a binding to a specific column in the database by name. Supports specification of precision and scale.
COLUMN_NAME_PS_LENGTH Represents a binding to a specific column in the database by name. Supports specification of precision, scale, and column length.
COLUMN_NAME_PS_LENGTH_STATUS Represents a binding to a specific column in the database by name. Supports specification of precision, scale, column length, and column status.
COLUMN_NAME_PS_STATUS Represents a binding to a specific column in the database by name. Supports specification of precision, scale, and column status.
COLUMN_NAME_STATUS Represents a binding to a specific column in the database by name. Supports specification of column status.
COLUMN_NAME_TYPE Represents a binding to a specific column in the database by name. Supports specification of data type.
COLUMN_NAME_TYPE_PS Represents a binding to a specific column in the database by name. Supports specification of data type, precision, and scale.
COLUMN_NAME_TYPE_SIZE Represents a binding to a specific column in the database by name. Supports specification of data type and size.
COLUMN_NAME_TYPE_STATUS Represents a binding to a specific column in the database by name. Supports specification of data type and column status.
END_COLUMN_MAP Marks the end of the column map entries.

Command Macros

Name Description
DEFINE_COMMAND Specifies the command that will be used to create the rowset when using the CCommand class. Accepts only string types matching the specified application type (ANSI or Unicode). It is recommended that you use DEFINE_COMMAND_EX instead of DEFINE_COMMAND.
DEFINE_COMMAND_EX Specifies the command that will be used to create the rowset when using the CCommand class. Supports ANSI and Unicode applications.

Parameter Map Macros

Name Description
BEGIN_PARAM_MAP Marks the beginning of the parameter map entries in the user record class.
END_PARAM_MAP Marks the end of the parameter map entries.
SET_PARAM_TYPE Specifies COLUMN_ENTRY macros that follow the SET_PARAM_TYPE macro as input, output, or input/output.

AtlTraceErrorRecords

Dumps OLE DB Error Record information to the dump device if an error is returned.

Syntax

inline void AtlTraceErrorRecords(HRESULT hrErr = S_OK);

Parameters

hErr
[in] An HRESULT returned by an OLE DB Consumer Template member function.

Remarks

If hErr is not S_OK, AtlTraceErrorRecords dumps OLE DB Error Record information to the dump device (the Debug tab of the Output window or a file). The Error Record information, which is obtained from the provider, includes row number, source, description, help file, context, and GUID for each error record entry. AtlTraceErrorRecords dumps this information only in debug builds. In release builds, it is an empty stub that is optimized out. For more information, see CDBErrorInfo Class.

BEGIN_ACCESSOR

Marks the beginning of an accessor entry.

Syntax

BEGIN_ACCESSOR(num, bAuto)

Parameters

num
[in] The zero-offset number for the accessor in this accessor map.

bAuto
[in] Specifies if this accessor is an auto accessor or a manual accessor. If true, the accessor is auto; if false, the accessor is manual. An auto accessor means data is fetched for you on move operations.

Remarks

In the case of multiple accessors on a rowset, you need to specify BEGIN_ACCESSOR_MAP and use the BEGIN_ACCESSOR macro for each individual accessor. The BEGIN_ACCESSOR macro is completed with the END_ACCESSOR macro. The BEGIN_ACCESSOR_MAP macro is completed with the END_ACCESSOR_MAP macro.

Example

See BEGIN_ACCESSOR_MAP.

BEGIN_ACCESSOR_MAP

Marks the beginning of the accessor map entries.

Syntax

BEGIN_ACCESSOR_MAP(x, num)

Parameters

x
[in] The name of the user record class.

num
[in] The number of accessors in this accessor map.

Remarks

In the case of multiple accessors on a rowset, you need to specify BEGIN_ACCESSOR_MAP at the beginning and use the BEGIN_ACCESSOR macro for each individual accessor. The BEGIN_ACCESSOR macro is completed with the END_ACCESSOR macro. The accessor map is completed with the END_ACCESSOR_MAP macro.

If you have only one accessor in the user record, use the macro BEGIN_COLUMN_MAP.

Example

class CArtistsAccessor
{
public:
// Data Elements
   TCHAR m_szFirstName[21];
   TCHAR m_szLastName[31];
   short m_nAge;

// Output binding map
BEGIN_ACCESSOR_MAP(CArtistsAccessor, 2)
   BEGIN_ACCESSOR(0, true)
      COLUMN_ENTRY(1, m_szFirstName)
      COLUMN_ENTRY(2, m_szLastName)
   END_ACCESSOR()
   BEGIN_ACCESSOR(1, false) // Not an auto accessor
      COLUMN_ENTRY(3, m_nAge)
   END_ACCESSOR()
END_ACCESSOR_MAP()

   HRESULT OpenDataSource()
   {
      CDataSource _db;
      _db.Open();
      return m_session.Open(_db);
   }

   void CloseDataSource()
   {
      m_session.Close();
   }

   CSession m_session;

   DEFINE_COMMAND_EX(CArtistsAccessor, L" \
   SELECT \
      FirstName, \
      LastName, \
      Age \
      FROM Artists")
};

END_ACCESSOR

Marks the end of an accessor entry.

Syntax

END_ACCESSOR()

Remarks

For multiple accessors on a rowset, you need to specify BEGIN_ACCESSOR_MAP and use the BEGIN_ACCESSOR macro for each individual accessor. The BEGIN_ACCESSOR macro is completed with the END_ACCESSOR macro. The BEGIN_ACCESSOR_MAP macro is completed with the END_ACCESSOR_MAP macro.

Example

See BEGIN_ACCESSOR_MAP.

END_ACCESSOR_MAP

Marks the end of the accessor map entries.

Syntax

END_ACCESSOR_MAP()

Remarks

For multiple accessors on a rowset, you need to specify BEGIN_ACCESSOR_MAP and use the BEGIN_ACCESSOR macro for each individual accessor. The BEGIN_ACCESSOR macro is completed with the END_ACCESSOR macro. The BEGIN_ACCESSOR_MAP macro is completed with the END_ACCESSOR_MAP macro.

Example

See BEGIN_ACCESSOR_MAP.

BEGIN_COLUMN_MAP

Marks the beginning of a column map entry.

Syntax

BEGIN_COLUMN_MAP(x)

Parameters

x
[in] The name of the user record class derived from CAccessor.

Remarks

This macro is used in the case of a single accessor on a rowset. If you have multiple accessors on a rowset, use BEGIN_ACCESSOR_MAP.

The BEGIN_COLUMN_MAP macro is completed with the END_COLUMN_MAP macro. This macro is used when there is only one accessor required in the user record.

Columns correspond to fields in the rowset you want to bind.

Example

Here is a sample column and parameter map:

BLOB_ENTRY

Used with BEGIN_COLUMN_MAP and END_COLUMN_MAP to bind a binary large object (BLOB).

Syntax

BLOB_ENTRY(nOrdinal, IID, flags, data)

Parameters

nOrdinal
[in] The column number.

IID
[in] Interface GUID, such as IDD_ISequentialStream, used to retrieve the BLOB.

flags
[in] Storage-mode flags as defined by the OLE Structured Storage model (for example, STGM_READ).

data
[in] The corresponding data member in the user record.

Example

See How Can I Retrieve a BLOB?.

BLOB_ENTRY_LENGTH

Used with BEGIN_COLUMN_MAP and END_COLUMN_MAP to bind a binary large object (BLOB). Similar to BLOB_ENTRY, except that this macro also gets the length in bytes of the BLOB column.

Syntax

BLOB_ENTRY_LENGTH(nOrdinal, IID, flags, data, length)

Parameters

nOrdinal
[in] The column number.

IID
[in] Interface GUID, such as IDD_ISequentialStream, used to retrieve the BLOB.

flags
[in] Storage-mode flags as defined by the OLE Structured Storage model (for example, STGM_READ).

data
[in] The corresponding data member in the user record.

length
[out] The (actual) length in bytes of the BLOB column.

Example

See How Can I Retrieve a BLOB?.

BLOB_ENTRY_LENGTH_STATUS

Used with BEGIN_COLUMN_MAP and END_COLUMN_MAP to bind a binary large object (BLOB). Similar to BLOB_ENTRY, except that this macro also gets the length and status of the BLOB column.

Syntax

BLOB_ENTRY_LENGTH_STATUS(
    nOrdinal,
    IID,
    flags,
    data,
    length,
    status )

Parameters

nOrdinal
[in] The column number.

IID
[in] Interface GUID, such as IDD_ISequentialStream, used to retrieve the BLOB.

flags
[in] Storage-mode flags as defined by the OLE Structured Storage model (for example, STGM_READ).

data
[in] The corresponding data member in the user record.

length
[out] The (actual) length in bytes of the BLOB column.

status
[out] The status of the BLOB data column.

Example

See How Can I Retrieve a BLOB?.

BLOB_ENTRY_STATUS

Used with BEGIN_COLUMN_MAP or BEGIN_ACCESSOR_MAP to bind a binary large object (BLOB). Similar to BLOB_ENTRY, except that this macro also gets the status of the BLOB column.

Syntax

BLOB_ENTRY_STATUS(nOrdinal, IID, flags, data, status)

Parameters

nOrdinal
[in] The column number.

IID
[in] Interface GUID, such as IDD_ISequentialStream, used to retrieve the BLOB.

flags
[in] Storage-mode flags as defined by the OLE Structured Storage model (for example, STGM_READ).

data
[in] The corresponding data member in the user record.

status
[out] The status of the BLOB field.

Example

See How Can I Retrieve a BLOB?.

BLOB_NAME

Used with BEGIN_COLUMN_MAP and END_COLUMN_MAP to bind a binary large object (BLOB). Similar to BLOB_ENTRY, except that this macro takes a column name instead of a column number.

Syntax

BLOB_NAME(pszName, IID, flags, data )

Parameters

pszName
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".

IID
[in] Interface GUID, such as IDD_ISequentialStream, used to retrieve the BLOB.

flags
[in] Storage-mode flags as defined by the OLE Structured Storage model (for example, STGM_READ).

data
[in] The corresponding data member in the user record.

Example

See How Can I Retrieve a BLOB?.

BLOB_NAME_LENGTH

Used with BEGIN_COLUMN_MAP and END_COLUMN_MAP to bind a binary large object (BLOB). Similar to BLOB_NAME, except that this macro also gets the length in bytes of the BLOB data column.

Syntax

BLOB_NAME_LENGTH(pszName, IID, flags, data, length )

Parameters

pszName
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".

IID
[in] Interface GUID, such as IDD_ISequentialStream, used to retrieve the BLOB.

flags
[in] Storage-mode flags as defined by the OLE Structured Storage model (for example, STGM_READ).

data
[in] The corresponding data member in the user record.

length
[out] The (actual) length in bytes of the BLOB column.

BLOB_NAME_LENGTH_STATUS

Used with BEGIN_COLUMN_MAP and END_COLUMN_MAP to bind a binary large object (BLOB). Similar to BLOB_NAME, except that this macro also gets the length and status of the BLOB data column.

Syntax

BLOB_NAME_LENGTH_STATUS(pszName, IID, flags, data, length, status )

Parameters

pszName
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".

IID
[in] Interface GUID, such as IDD_ISequentialStream, used to retrieve the BLOB.

flags
[in] Storage-mode flags as defined by the OLE Structured Storage model (for example, STGM_READ).

data
[in] The corresponding data member in the user record.

length
[out] The (actual) length in bytes of the BLOB column.

status
[out] The status of the BLOB field.

BLOB_NAME_STATUS

Used with BEGIN_COLUMN_MAP and END_COLUMN_MAP to bind a binary large object (BLOB). Similar to BLOB_NAME, except that this macro also gets the status of the BLOB data column.

Syntax

BLOB_NAME_STATUS(pszName, IID, flags, data, status )

Parameters

pszName
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".

IID
[in] Interface GUID, such as IDD_ISequentialStream, used to retrieve the BLOB.

flags
[in] Storage-mode flags as defined by the OLE Structured Storage model (for example, STGM_READ).

data
[in] The corresponding data member in the user record.

status
[out] The status of the BLOB field.

BOOKMARK_ENTRY

Binds the bookmark column.

Syntax

BOOKMARK_ENTRY(variable)

Parameters

variable
[in] The variable to be bound to the bookmark column.

Example

class CArtistsBookmark
{
public:
// Data Elements
   CBookmark<4> m_bookmark;
   short m_nAge;
   TCHAR m_szFirstName[21];
   TCHAR m_szLastName[31];

// Output binding map
BEGIN_COLUMN_MAP(CArtistsBookmark)
   BOOKMARK_ENTRY(m_bookmark)
   COLUMN_ENTRY(1, m_nAge)
   COLUMN_ENTRY(2, m_szFirstName)
   COLUMN_ENTRY(3, m_szLastName)
END_COLUMN_MAP()

   void GetRowsetProperties(CDBPropSet* pPropSet)
   {
      pPropSet->AddProperty(DBPROP_BOOKMARKS, true);
   }

   HRESULT OpenDataSource()
   {
      CDataSource _db;
      _db.Open();
      return m_session.Open(_db);
   }

   void CloseDataSource()
   {
      m_session.Close();
   }

   CSession m_session;

   DEFINE_COMMAND_EX(CArtistsBookmark, L" \
   SELECT \
      Age, \
      FirstName, \
      LastName \
      FROM Artists")
};

For more information, see Using Bookmarks and CBookmark Class.

COLUMN_ENTRY

Represents a binding on the rowset to the specific column in the rowset.

Syntax

COLUMN_ENTRY(nOrdinal, data)

Parameters

See DBBINDING in the OLE DB Programmer's Reference.

nOrdinal
[in] The column number.

data
[in] The corresponding data member in the user record.

Remarks

The COLUMN_ENTRY macro is used in the following places:

Example

See the examples in the macro topics, BEGIN_COLUMN_MAP and BEGIN_ACCESSOR_MAP.

COLUMN_ENTRY_EX

Represents a binding on the rowset to the specific column in the database.

Syntax

COLUMN_ENTRY_EX(nOrdinal, wType, nLength, nPrecision, nScale, data, length, status)

Parameters

See DBBINDING in the OLE DB Programmer's Reference.

nOrdinal
[in] The column number.

wType
[in] The data type.

nLength
[in] The data size in bytes.

nPrecision
[in] The maximum precision to use when getting data and wType is DBTYPE_NUMERIC. Otherwise, this parameter is ignored.

nScale
[in] The scale to use when getting data and wType is DBTYPE_NUMERIC or DBTYPE_DECIMAL.

data
[in] The corresponding data member in the user record.

length
[in] The variable to be bound to the column length.

status
[in] The variable to be bound to the column status.

Remarks

The COLUMN_ENTRY_EX macro is used in the following places:

Example

See BOOKMARK_ENTRY.

COLUMN_ENTRY_LENGTH

Represents a binding on the rowset to the specific column in the database.

Syntax

COLUMN_ENTRY_LENGTH(nOrdinal, data, length)

Parameters

See DBBINDING in the OLE DB Programmer's Reference.

nOrdinal
[in] The column number, starting with one. Bookmark corresponds to column zero.

data
[in] The corresponding data member in the user record.

length
[in] The variable to be bound to the column length.

Remarks

This macro supports the length variable. It is used in the following places:

COLUMN_ENTRY_LENGTH_STATUS

Represents a binding on the rowset to the specific column in the database.

Syntax

COLUMN_ENTRY_LENGTH_STATUS(nOrdinal, data, length, status)

Parameters

See DBBINDING in the OLE DB Programmer's Reference.

nOrdinal
[in] The column number.

data
[in] The corresponding data member in the user record.

length
[in] The variable to be bound to the column length.

status
[in] The variable to be bound to the column status.

Remarks

Use this macro when you want to support length and status variables. It is used in the following places:

COLUMN_ENTRY_PS

Represents a binding on the rowset to the specific column in the rowset.

Syntax

COLUMN_ENTRY_PS(nOrdinal, nPrecision, nScale, data)

Parameters

See DBBINDING in the OLE DB Programmer's Reference.

nOrdinal
[in] The column number.

nPrecision
[in] The maximum precision of the column you want to bind.

nScale
[in] The scale of the column you want to bind.

data
[in] The corresponding data member in the user record.

Remarks

Allows you to specify the precision and scale of the column you want to bind. It is used in the following places:

COLUMN_ENTRY_PS_LENGTH

Represents a binding on the rowset to the specific column in the database.

Syntax

COLUMN_ENTRY_PS_LENGTH(nOrdinal, nPrecision, nScale, data, length)

Parameters

See DBBINDING in the OLE DB Programmer's Reference.

nOrdinal
[in] The column number, starting with one. Bookmark corresponds to column zero.

nPrecision
[in] The maximum precision of the column you want to bind.

nScale
[in] The scale of the column you want to bind.

data
[in] The corresponding data member in the user record.

length
[in] The variable to be bound to the column length.

Remarks

Allows you to specify the precision and scale of the column you want to bind. This macro supports the length variable. It is used in the following places:

COLUMN_ENTRY_PS_LENGTH_STATUS

Represents a binding on the rowset to the specific column in the database.

Syntax

COLUMN_ENTRY_PS_LENGTH_STATUS(nOrdinal, nPrecision, nScale, data, length, status)

Parameters

See DBBINDING in the OLE DB Programmer's Reference.

nOrdinal
[in] The column number.

nPrecision
[in] The maximum precision of the column you want to bind.

nScale
[in] The scale of the column you want to bind.

data
[in] The corresponding data member in the user record.

length
[in] The variable to be bound to the column length.

status
[in] The variable to be bound to the column status.

Remarks

Allows you to specify the precision and scale of the column you want to bind. Use this macro when you want to support length and status variables. It is used in the following places:

COLUMN_ENTRY_PS_STATUS

Represents a binding on the rowset to the specific column in the database.

Syntax

COLUMN_ENTRY_PS_STATUS(nOrdinal, nPrecision, nScale, data, status)

Parameters

See DBBINDING in the OLE DB Programmer's Reference.

nOrdinal
[in] The column number.

nPrecision
[in] The maximum precision of the column you want to bind.

nScale
[in] The scale of the column you want to bind.

data
[in] The corresponding data member in the user record.

status
[in] The variable to be bound to the column status.

Remarks

Allows you to specify the precision and scale of the column you want to bind. This macro supports the status variable. It is used in the following places:

COLUMN_ENTRY_STATUS

Represents a binding on the rowset to the specific column in the database.

Syntax

COLUMN_ENTRY_STATUS(nOrdinal, data, status)

Parameters

See DBBINDING in the OLE DB Programmer's Reference.

nOrdinal
[in] The column number.

data
[in] The corresponding data member in the user record.

status
[in] The variable to be bound to the column status.

Remarks

This macro supports the status variable. It is used in the following places:

COLUMN_ENTRY_TYPE

Represents a binding to the specific column in the database. Supports type parameter.

Syntax

COLUMN_ENTRY_TYPE (nOrdinal, wType, data)

Parameters

nOrdinal
[in] The column number.

wType
[in] Data type of column entry.

data
[in] The corresponding data member in the user record.

Remarks

This macro is a specialized variant of the COLUMN_ENTRY macro that provides a means of specifying data type.

COLUMN_ENTRY_TYPE_SIZE

Represents a binding to the specific column in the database. Supports type and size parameters.

Syntax

COLUMN_ENTRY_TYPE_SIZE(nOrdinal, wType, nLength, data)

Parameters

nOrdinal
[in] The column number.

wType
[in] Data type of column entry.

nLength
[in] Size of column entry in bytes.

data
[in] The corresponding data member in the user record.

Remarks

This macro is a specialized variant of the COLUMN_ENTRY macro that provides a means of specifying data size and type.

COLUMN_NAME

Represents a binding on the rowset to the specific column in the rowset. Similar to COLUMN_ENTRY, except that this macro takes the column name instead of the column number.

Syntax

COLUMN_NAME(pszName, data)

Parameters

pszName
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".

data
[in] The corresponding data member in the user record.

Remarks

The COLUMN_NAME_* macros are used in the same places as COLUMN_ENTRY:

COLUMN_NAME_EX

Represents a binding on the rowset to the specific column in the rowset. Similar to COLUMN_NAME, except that this macro also takes data type, size, precision, scale, column length, and column status.

Syntax

COLUMN_NAME_EX(pszName, wType, nLength, nPrecision, nScale, data, length, status )

Parameters

pszName
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".

wType
[in] The data type.

nLength
[in] The data size in bytes.

nPrecision
[in] The maximum precision to use when getting data and wType is DBTYPE_NUMERIC. Otherwise, this parameter is ignored.

nScale
[in] The scale to use when getting data and wType is DBTYPE_NUMERIC or DBTYPE_DECIMAL.

data
[in] The corresponding data member in the user record.

length
[in] The variable to be bound to the column length.

status
[in] The variable to be bound to the column status.

Remarks

See COLUMN_NAME for information on where the COLUMN_NAME_* macros are used.

COLUMN_NAME_LENGTH

Represents a binding on the rowset to the specific column in the rowset. Similar to COLUMN_NAME, except that this macro also takes column length.

Syntax

COLUMN_NAME_LENGTH(pszName, data, length)

Parameters

pszName
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".

data
[in] The corresponding data member in the user record.

length
[in] The variable to be bound to the column length.

Remarks

See COLUMN_NAME for information on where the COLUMN_NAME_* macros are used.

COLUMN_NAME_LENGTH_STATUS

Represents a binding on the rowset to the specific column in the rowset. Similar to COLUMN_NAME, except that this macro also takes column length and column status.

Syntax

COLUMN_NAME_LENGTH_STATUS(pszName, data, length, status )

Parameters

pszName
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".

data
[in] The corresponding data member in the user record.

length
[in] The variable to be bound to the column length.

status
[in] The variable to be bound to the column status.

Remarks

See COLUMN_NAME for information on where the COLUMN_NAME_* macros are used.

COLUMN_NAME_PS

Represents a binding on the rowset to the specific column in the rowset. Similar to COLUMN_NAME, except that this macro also takes precision and scale.

Syntax

COLUMN_NAME_PS(pszName, nPrecision, nScale, data )

Parameters

pszName
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".

nPrecision
[in] The maximum precision of the column you want to bind.

nScale
[in] The scale of the column you want to bind.

data
[in] The corresponding data member in the user record.

Remarks

See COLUMN_NAME for information on where the COLUMN_NAME_* macros are used.

COLUMN_NAME_PS_LENGTH

Represents a binding on the rowset to the specific column in the rowset. Similar to COLUMN_NAME, except that this macro also takes precision, scale, and column length.

Syntax

COLUMN_NAME_PS_LENGTH(pszName, nPrecision, nScale, data, length )

Parameters

pszName
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".

nPrecision
[in] The maximum precision of the column you want to bind.

nScale
[in] The scale of the column you want to bind.

data
[in] The corresponding data member in the user record.

length
[in] The variable to be bound to the column length.

Remarks

See COLUMN_NAME for information on where the COLUMN_NAME_* macros are used.

COLUMN_NAME_PS_LENGTH_STATUS

Represents a binding on the rowset to the specific column in the rowset. Similar to COLUMN_NAME, except that this macro also takes precision, scale, column length, and column status.

Syntax

COLUMN_NAME_PS_LENGTH_STATUS(pszName, nPrecision, nScale, data, length, status )

Parameters

pszName
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".

nPrecision
[in] The maximum precision of the column you want to bind.

nScale
[in] The scale of the column you want to bind.

data
[in] The corresponding data member in the user record.

length
[in] The variable to be bound to the column length.

status
[in] The variable to be bound to the column status.

Remarks

See COLUMN_NAME for information on where the COLUMN_NAME_* macros are used.

COLUMN_NAME_PS_STATUS

Represents a binding on the rowset to the specific column in the rowset. Similar to COLUMN_NAME, except that this macro also takes precision, scale, and column status.

Syntax

COLUMN_NAME_PS_STATUS(pszName, nPrecision, nScale, data, status )

Parameters

pszName
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".

nPrecision
[in] The maximum precision of the column you want to bind.

nScale
[in] The scale of the column you want to bind.

data
[in] The corresponding data member in the user record.

status
[in] The variable to be bound to the column status.

Remarks

See COLUMN_NAME for information on where the COLUMN_NAME_* macros are used.

COLUMN_NAME_STATUS

Represents a binding on the rowset to the specific column in the rowset. Similar to COLUMN_NAME, except that this macro also takes column status.

Syntax

COLUMN_NAME_STATUS(pszName, data, status )

Parameters

pszName
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".

data
[in] The corresponding data member in the user record.

status
[in] The variable to be bound to the column status.

Remarks

See COLUMN_NAME for information on where the COLUMN_NAME_* macros are used.

COLUMN_NAME_TYPE

Represents a binding on the rowset to the specific column in the rowset. Similar to COLUMN_NAME, except that this macro also takes data type.

Syntax

COLUMN_NAME_TYPE(pszName, wType, data)

Parameters

pszName
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".

wType
[in] The data type.

data
[in] The corresponding data member in the user record.

Remarks

See COLUMN_NAME for information on where the COLUMN_NAME_* macros are used.

COLUMN_NAME_TYPE_PS

Represents a binding on the rowset to the specific column in the rowset. Similar to COLUMN_NAME, except that this macro also takes data type, precision, and scale.

Syntax

COLUMN_NAME_TYPE_PS(pszName, wType, nPrecision, nScale, data)

Parameters

pszName
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".

wType
[in] The data type.

nPrecision
[in] The maximum precision to use when getting data and wType is DBTYPE_NUMERIC. Otherwise, this parameter is ignored.

nScale
[in] The scale to use when getting data and wType is DBTYPE_NUMERIC or DBTYPE_DECIMAL.

data
[in] The corresponding data member in the user record.

Remarks

See COLUMN_NAME for information on where the COLUMN_NAME_* macros are used.

COLUMN_NAME_TYPE_SIZE

Represents a binding on the rowset to the specific column in the rowset. Similar to COLUMN_NAME, except that this macro also takes data type and size.

Syntax

COLUMN_NAME_TYPE_SIZE(pszName, wType, nLength, data)

Parameters

pszName
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".

wType
[in] The data type.

nLength
[in] The data size in bytes.

data
[in] The corresponding data member in the user record.

Remarks

See COLUMN_NAME for information on where the COLUMN_NAME_* macros are used.

COLUMN_NAME_TYPE_STATUS

Represents a binding on the rowset to the specific column in the rowset. Similar to COLUMN_NAME, except that this macro also takes data type and column status.

Syntax

COLUMN_NAME_TYPE_STATUS(pszName, wType, status, data)

Parameters

pszName
[in] A pointer to the column name. The name must be a Unicode string. You can accomplish this by putting an 'L' in front of the name, for example: L"MyColumn".

wType
[in] The data type.

status
[in] The variable to be bound to the column status.

data
[in] The corresponding data member in the user record.

Remarks

See COLUMN_NAME for information on where the COLUMN_NAME_* macros are used.

END_COLUMN_MAP

Marks the end of the column map entries.

Syntax

END_COLUMN_MAP()

Remarks

It is used with a single accessor on a rowset. The BEGIN_COLUMN_MAP macro is completed with the END_COLUMN_MAP macro.

Example

See BEGIN_COLUMN_MAP.

DEFINE_COMMAND

Specifies the command that will be used to create the rowset when using the CCommand class. Accepts only string types matching the specified application type (ANSI or Unicode).

Note

It is recommended that you use DEFINE_COMMAND_EX instead of DEFINE_COMMAND.

Syntax

DEFINE_COMMAND(x, szCommand)

Parameters

x
[in] The name of the user record (command) class.

szCommand
[in] The command string that will be used to create the rowset when using CCommand.

Remarks

The command string that you specify will be used as the default if you do not specify command text in the CCommand::Open method.

This macro accepts ANSI strings if you build your application as ANSI, or Unicode strings if you build your application as Unicode. It is recommended that you use DEFINE_COMMAND_EX instead of DEFINE_COMMAND, because the former accepts Unicode strings, regardless of the ANSI or Unicode application type.

Example

See BOOKMARK_ENTRY.

DEFINE_COMMAND_EX

Specifies the command that will be used to create the rowset when using the CCommand class. Supports Unicode and ANSI applications.

Syntax

DEFINE_COMMAND_EX(x, wszCommand)

Parameters

x
[in] The name of the user record (command) class.

wszCommand
[in] The command string that will be used to create the rowset when using CCommand.

Remarks

The command string that you specify will be used as the default if you do not specify command text in the CCommand::Open method.

This macro accepts Unicode strings, regardless of the application type. This macro is preferred over DEFINE_COMMAND because it supports Unicode as well as ANSI applications.

Example

See BOOKMARK_ENTRY.

BEGIN_PARAM_MAP

Marks the beginning of the parameter map entries.

Syntax

BEGIN_PARAM_MAP(x)

Parameters

x
[in] The name of the user record class.

Remarks

Parameters are used by commands.

Example

See the example for the BEGIN_COLUMN_MAP macro.

END_PARAM_MAP

Marks the end of the parameter map entries.

Syntax

END_PARAM_MAP()

Example

See the example for the BEGIN_PARAM_MAP macro.

SET_PARAM_TYPE

Specifies COLUMN_ENTRY macros that follow the SET_PARAM_TYPE macro input, output, or input/output.

Syntax

SET_PARAM_TYPE(type)

Parameters

type
[in] The type to set for the parameter.

Remarks

Providers support only parameter input/output types that are supported by the underlying data source. The type is a combination of one or more DBPARAMIO values (see DBBINDING Structures in the OLE DB Programmer's Reference):

  • DBPARAMIO_NOTPARAM The accessor has no parameters. Typically, you set eParamIO to this value in row accessors to remind the user that parameters are ignored.

  • DBPARAMIO_INPUT An input parameter.

  • DBPARAMIO_OUTPUT An output parameter.

  • DBPARAMIO_INPUT | DBPARAMIO_OUTPUT The parameter is both an input and an output parameter.

Example

class CArtistsProperty
{
public:
   short m_nReturn;
   short m_nAge;
   TCHAR m_szFirstName[21];
   TCHAR m_szLastName[31];

BEGIN_PARAM_MAP(CArtistsProperty)
   SET_PARAM_TYPE(DBPARAMIO_OUTPUT)
   COLUMN_ENTRY(1, m_nReturn)
   SET_PARAM_TYPE(DBPARAMIO_INPUT)
   COLUMN_ENTRY(2, m_nAge)
END_PARAM_MAP()

BEGIN_COLUMN_MAP(CArtistsProperty)
   COLUMN_ENTRY(1, m_szFirstName)
   COLUMN_ENTRY(2, m_szLastName)
END_COLUMN_MAP()

   HRESULT OpenDataSource()
   {
      CDataSource _db;
      _db.Open();
      return m_session.Open(_db);
   }

   void CloseDataSource()
   {
      m_session.Close();
   }

   CSession m_session;

   DEFINE_COMMAND_EX(CArtistsProperty, L" \
      { ? = SELECT Age FROM Artists WHERE Age < ? }")
};

Requirements

Header: atldbcli.h

See also

Macros and Global Functions for OLE DB Consumer Templates
OLE DB Consumer Templates
OLE DB Consumer Templates Reference