OLE DB를 사용한 인덱스 생성

Microsoft SQL Server Compact 4.0용 OLE DB 공급자는 IIndexDefinition::CreateIndex를 통해 인덱스를 만들 수 있는 기능을 제공합니다.

SQL Server Compact 4.0의 인덱스 사용에는 제한 사항이 있습니다. 자세한 내용은 OLE DB 인덱스(SQL Server Compact)OLE DB의 인덱스 변경을 참조하십시오.

다음 예에서는 SQL Server Compact 4.0용 OLE DB 공급자를 사용하여 데이터베이스의 Employees 테이블에서 LastName 및 FirstName 열에 대한 복합 인덱스를 만드는 방법을 보여 줍니다.

//Create an index on two columns.
HRESULT             hr;
DBID                TableName;
DBID                IndexName;
DBPROP              dbprop[1];
DBPROPSET           dbpropset[1];
DBPROP              indexdbprop[2];
DBPROPSET           indexdbpropset[1];
DBINDEXCOLUMNDESC   rgIndexColumnDescs[2];
DBID                dbidColumn1;
DBID                dbidColumn2;
IDBInitialize       *pIDBInitialize     = NULL;        
IDBProperties       *pIDBProperties        = NULL;        
IDBCreateSession    *pIDBCreateSession  = NULL;
IIndexDefinition    *pIIndexDefinition  = NULL;


VariantInit(&dbprop[0].vValue);        
VariantInit(&indexdbprop[0].vValue);

// Create an instance of the OLE DB provider.
hr = CoCreateInstance(    CLSID_SQLSERVERCE, 0, CLSCTX_INPROC_SERVER,
    IID_IDBInitialize, (void**)&pIDBInitialize);
if(FAILED(hr))
{
    goto Exit;
}

// Initialize a property with name of database.
// Open an exsiting database myDatabase.
dbprop[0].dwPropertyID     = DBPROP_INIT_DATASOURCE;
dbprop[0].dwOptions         = DBPROPOPTIONS_REQUIRED;
dbprop[0].vValue.vt         = VT_BSTR;
dbprop[0].vValue.bstrVal = L"\\windows\\MyDB.sdf";
if(NULL == dbprop[0].vValue.bstrVal)
{
    hr = E_OUTOFMEMORY;
    goto Exit;
}

// Initialize the property set.
dbpropset[0].guidPropertySet = DBPROPSET_DBINIT;
dbpropset[0].rgProperties     = dbprop;
dbpropset[0].cProperties     = sizeof(dbprop)/sizeof(dbprop[0]);

//Set initialization properties.
hr = pIDBInitialize->QueryInterface(IID_IDBProperties, 
    
(void **)&pIDBProperties);
if(FAILED(hr))
{
    goto Exit;
}

// Sets properties in the Data Source and initialization property groups
hr = pIDBProperties->SetProperties(1, dbpropset); 
if(FAILED(hr))
{
    goto Exit;
}

// Initializes a data source object 
hr = pIDBInitialize->Initialize();
if(FAILED(hr))
{
    goto Exit;
}

// Get the IDBCreateSession interface.
hr = pIDBInitialize->QueryInterface(IID_IDBCreateSession,
    (void**)&pIDBCreateSession);
if (FAILED(hr))
{
    //Send an error-specific message and do error handling.
    goto Exit;
}

// Create a session object. 
hr = pIDBCreateSession->CreateSession(NULL, IID_IIndexDefinition, 
    (IUnknown**) &pIIndexDefinition);

// (This sample assumes that we have information about the Employees table.
// database schema.)
// Prepare the table name DBID as Employees.
TableName.eKind          = DBKIND_NAME;
TableName.uName.pwszName = L"Employees";

// Prepare index name DBID as full_name_index.
IndexName.eKind          = DBKIND_NAME;
IndexName.uName.pwszName = L"full_name_index";

// Set up properties for IIndexDefinition::CreateIndex call. For this 
// index,we enforce uniqueness through the DBPROP_INDEX_NULLS property.
// Index properties must have colid set to DB_NULLID.
indexdbprop[0].dwPropertyID   = DBPROP_INDEX_NULLS;
indexdbprop[0].dwOptions      = DBPROPOPTIONS_REQUIRED;
indexdbprop[0].vValue.vt      = VT_I4;
indexdbprop[0].vValue.lVal    = DBPROPVAL_IN_DISALLOWNULL;
indexdbprop[0].colid          = DB_NULLID; 

// Initialize the property set.
indexdbpropset[0].guidPropertySet = DBPROPSET_INDEX;
indexdbpropset[0].rgProperties    = indexdbprop;
indexdbpropset[0].cProperties     = sizeof(indexdbprop)/sizeof(indexdbprop[0]);
 
// Set up DBINDEXCOLUMNDESC structures to define the columns in the  
// index and the ordering for each column within that index.
rgIndexColumnDescs[0].eIndexColOrder = DBINDEX_COL_ORDER_ASC;
rgIndexColumnDescs[0].pColumnID      = &dbidColumn1;
rgIndexColumnDescs[1].eIndexColOrder = DBINDEX_COL_ORDER_ASC;
rgIndexColumnDescs[1].pColumnID      = &dbidColumn2;

// Specify the column names for the composite index on 
// LastName and FirstName.
dbidColumn1.eKind = DBKIND_NAME;
dbidColumn1.uName.pwszName = L"LastName";
dbidColumn2.eKind = DBKIND_NAME;
dbidColumn2.uName.pwszName = L"FirstName";

// Create a two-column composite index named full_name_index over the 
// LastName and FirstName columns in the Employees table. 
hr = pIIndexDefinition->CreateIndex(&TableName, &IndexName,
    sizeof(rgIndexColumnDescs)/sizeof(rgIndexColumnDescs[0]),
    rgIndexColumnDescs, sizeof(indexdbpropset)/sizeof(indexdbpropset[0]),
    indexdbpropset, NULL);

Exit: 

// When finished, clear the properties arrays and release interfaces.
// Uninitialize the environment.

return;
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