有没有人有一个示例代码,给定数据库文件显示所有用户表的名称？
我对.NET代码不感兴趣,只是C语言.
我试图让OLE DB完成任务 – 相比之下,火箭科学似乎是儿童游戏.
解决方法
我将假设SQL Server CE 3.0 / 3.1但是,供您参考,这里是我知道的提供程序字符串：
> SQL Server CE 3.0 / 3.1 – Microsoft.SQLLITE.MOBILE.OLEDB.3.0
> SQL Server CE 3.5 – Microsoft.SQLSERVER.CE.OLEDB.3.5
另外,我将为您提供两个代码示例：
>“SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES”上的ICommandText
> DBSCHEMA_TABLES上的IDBSchemaRowset
我正在为您提供样本作为C控制台应用程序,并使用ATL来缩短代码.代码完整且有效,但不包括HRESULT hr的必要错误检查.
这是用于查询SQL Server CE 3.0 / 3.1数据库以使用ICommandText和IRowset执行“SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES”的C控制台应用程序示例：
#include <stdio.h>
#include <tchar.h>
#include <windows.h>
#include <oledb.h>
#include <atlbase.h>
int _tmain(int argc,_TCHAR* argv[])
{
HRESULT hr = S_OK;
hr = CoInitializeEx(NULL,COINIT_MULTITHREADED);
// Connect to SQL Server.
CComPtr<IDBInitialize> spIDBInitialize;
hr = spIDBInitialize.CoCreateInstance(OLESTR("Microsoft.SQLLITE.MOBILE.OLEDB.3.0"));
CComPtr<IDBProperties> spIDBProperties;
hr = spIDBInitialize->QueryInterface(&spIDBProperties);
CComVariant varDataSource(OLESTR("InsertYourSampleDatabase.SDF"));
DBPROP prop = { DBPROP_INIT_DATASOURCE,DBPROPOPTIONS_REQUIRED,DB_NULLID,varDataSource };
DBPROPSET propSet = {&prop,1,DBPROPSET_DBINIT};
hr = spIDBProperties->SetProperties(1,&propSet);
spIDBProperties = NULL;
hr = spIDBInitialize->Initialize();
// Execute the query.
CComPtr<IDBCreateSession> spIDBCreateSession;
hr = spIDBInitialize->QueryInterface(&spIDBCreateSession);
CComPtr<IDBCreateCommand> spIDBCreateCommand;
hr = spIDBCreateSession->CreateSession(NULL,IID_IDBCreateCommand,(IUnknown**) &spIDBCreateCommand);
spIDBCreateSession = NULL;
CComPtr<ICommandText> spICommandText;
hr = spIDBCreateCommand->CreateCommand(NULL,IID_ICommandText,(IUnknown**) &spICommandText);
spIDBCreateCommand = NULL;
hr = spICommandText->SetCommandText(DBGUID_SQL,OLESTR("SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES"));
DBROWCOUNT cRowsAffected = 0;
CComPtr<IRowset> spIRowset;
hr = spICommandText->Execute(NULL,IID_IRowset,NULL,&cRowsAffected,(IUnknown**) &spIRowset);
spICommandText = NULL;
// Retrieve records.
HROW hRow = NULL;
HROW *rghRow = &hRow;
DBCOUNTITEM cRowsObtained = 0;
hr = spIRowset->GetNextRows(DB_NULL_HCHAPTER,&cRowsObtained,&rghRow);
while (hr == S_OK && cRowsObtained == 1)
{
// Fetch the TABLE_NAME field.
struct
{
DBSTATUS dbTableNameStatus;
ULONG nTableNameLength;
WCHAR szTableName[128 + 1];
} data = {0};
DBBINDING Binding = {0};
Binding.iOrdinal = 1;
Binding.obValue = sizeof(DBSTATUS) + sizeof(ULONG);
Binding.obLength = sizeof(DBSTATUS);
Binding.obStatus = 0;
Binding.pTypeInfo = NULL;
Binding.pObject = NULL;
Binding.pBindExt = NULL;
Binding.dwPart = DBPART_STATUS | DBPART_LENGTH | DBPART_VALUE;
Binding.dwMemOwner = DBMEMOWNER_CLIENTOWNED;
Binding.eParamIO = DBPARAMIO_NOTPARAM;
Binding.cbMaxLen = (128 + 1) * sizeof(WCHAR);
Binding.wType = DBTYPE_WSTR;
Binding.dwFlags = 0;
Binding.bPrecision = 0;
Binding.bScale = 0;
CComPtr<IAccessor> spIAccessor;
hr = spIRowset->QueryInterface(IID_IAccessor,(void**) &spIAccessor);
HACCESSOR hAccessor = NULL;
hr = spIAccessor->CreateAccessor(DBACCESSOR_ROWDATA,&Binding,&hAccessor,NULL);
hr = spIRowset->GetData(hRow,hAccessor,&data);
DBREFCOUNT cRefCount = 0;
hr = spIAccessor->ReleaseAccessor(hAccessor,&cRefCount);
spIAccessor = NULL;
// @@TODO: Do something with data.szTableName and data.nTableNameLength
_tprintf(_T("%s\n"),data.szTableName);
// Fetch next row of data.
hr = spIRowset->ReleaseRows(1,rghRow,NULL);
cRowsObtained = 0;
hr = spIRowset->GetNextRows(DB_NULL_HCHAPTER,&rghRow);
}
// Release everything
spIRowset = NULL;
spIDBInitialize = NULL;
CoUninitialize();
return 0;
}
这是用于查询SQL Server CE 3.0 / 3.1数据库以使用IDBSchemaRowset和IRowset浏览表的C控制台应用程序示例(请注意,TABLE_NAME现在位于iOrdinal 3而不是1)：
#include <stdio.h>
#include <tchar.h>
#include <windows.h>
#include <oledb.h>
#include <atlbase.h>
int _tmain(int argc,&propSet);
spIDBProperties = NULL;
hr = spIDBInitialize->Initialize();
// Execute the query.
CComPtr<IDBCreateSession> spIDBCreateSession;
hr = spIDBInitialize->QueryInterface(&spIDBCreateSession);
CComPtr<IDBSchemaRowset> spIDBSchemaRowset;
hr = spIDBCreateSession->CreateSession(NULL,IID_IDBSchemaRowset,(IUnknown**) &spIDBSchemaRowset);
spIDBCreateSession = NULL;
CComVariant rgRestrictions[CRESTRICTIONS_DBSCHEMA_TABLES];
// rgRestrictions[2] = OLESTR("CENSUS"); TABLE_NAME restriction
rgRestrictions[3] = OLESTR("TABLE"); // TABLE_TYPE restriction
CComPtr<IRowset> spIRowset;
hr = spIDBSchemaRowset->GetRowset(NULL,DBSCHEMA_TABLES,CRESTRICTIONS_DBSCHEMA_TABLES,rgRestrictions,(IUnknown**) &spIRowset);
spIDBSchemaRowset = NULL;
// Retrieve records.
HROW hRow = NULL;
HROW *rghRow = &hRow;
DBCOUNTITEM cRowsObtained = 0;
hr = spIRowset->GetNextRows(DB_NULL_HCHAPTER,&rghRow);
while (hr == S_OK && cRowsObtained == 1)
{
// Fetch the TABLE_NAME field.
struct
{
DBSTATUS dbTableNameStatus;
ULONG nTableNameLength;
WCHAR szTableName[128 + 1];
} data = {0};
DBBINDING Binding = {0};
Binding.iOrdinal = 3;
Binding.obValue = sizeof(DBSTATUS) + sizeof(ULONG);
Binding.obLength = sizeof(DBSTATUS);
Binding.obStatus = 0;
Binding.pTypeInfo = NULL;
Binding.pObject = NULL;
Binding.pBindExt = NULL;
Binding.dwPart = DBPART_STATUS | DBPART_LENGTH | DBPART_VALUE;
Binding.dwMemOwner = DBMEMOWNER_CLIENTOWNED;
Binding.eParamIO = DBPARAMIO_NOTPARAM;
Binding.cbMaxLen = (128 + 1) * sizeof(WCHAR);
Binding.wType = DBTYPE_WSTR;
Binding.dwFlags = 0;
Binding.bPrecision = 0;
Binding.bScale = 0;
CComPtr<IAccessor> spIAccessor;
hr = spIRowset->QueryInterface(IID_IAccessor,&rghRow);
}
// Release everything
spIRowset = NULL;
spIDBInitialize = NULL;
CoUninitialize();
return 0;
}
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