使用EVC4创建基于对话框的工程，增加一按键并在其响应中Copy sqlce.chm中Creating Databases部分代码进行测试。记录过程如下：
1) error C2065: 'DBPROPSET' : undeclared identifier 等79个编译错误
解决方法：在StdAfx.h中增加以下几个头文件 ：
1 #include <oledb.h> 2 #include <oledberr.h> 3 #include <coguid.h> 4 #include "ca_mergex20.h" 5 #include "ssceoledb.h" //DBPROPSET
注：在CSDN上有一帖子，说明除了以上内容外，还需要修改并增加以下内容：
1 修改StdAfx.h 2 //#define VC_EXTRALEAN // Exclude rarely-used stuff from Windows 3 //上面这条一定要注释掉的,并加入以下引用 4 //////////////////////////////////////////////////////////////////////////////// 5 //以下这几句很重要,否则编译会提示你错误 6 #define DBINITCONSTANTS 7 #define INITGUID
验证结果：不需要修改并增加以上内容，否则会产生错误：
StdAfx.obj : error LNK2005: IID_IUnknown already defined in dd2Dlg.obj ARMV4IDbg/dd2.exe : fatal error LNK1169: one or more multiply defined symbols found
2) 编译产生以下错误：
ssceoledb.h(74) : error C2061: syntax error : identifier 'DBPROPSET' ssceoledb.h(100) : error C2061: syntax error : identifier 'HCHAPTER' ssceoledb.h(112) : error C2061: syntax error : identifier 'HCHAPTER' ssceoledb.h(116) : error C2061: syntax error : identifier 'HCHAPTER'
解决方法：更新一下SqlCe里的ssceoldb.h文件。下载 http://download.microsoft.com/download/d/0/3/d0337fad-0a9d-4c87-9fe2-c5a2916c7b80/ssceoledb.exe,其中是ssceoldb.h的压缩文件，解压后覆盖SqlCe安装目录的文件。
也可以参考下面的网站： http://support.microsoft.com/default.aspx?scid=kb;en-us;825393
至此，SQLCE.chm中Creating Databases部分代码编译成功!
调试时，发现CoCreateInstance()失败，分析原因是COM未初始化。所以在应用开始与结束时分别调用：CoInitializeEx(NULL, COINIT_MULTITHREADED);和CoUninitialize();
调试代码执行完成，但功能是否实现待分析。
Creating Databases To create a new database, you must specify the DBPROP_INIT_DATASOURCE property to specify a name for the database.
Creating Secure Databases To create an encrypted database using the OLE DB Provider for SQL Server CE, you must pass the provider-specific property DBPROP_SSCE_ENCRYPTDATABASE as VARIANT_TRUE and specify a password by using the provider-specific property DBPROP_SSCE_DBPASSWORD.
示例代码如下(以下代码即为建立SQL CE时的调试代码)：
1 //Object declarations 2 HRESULT hr = NOERROR; 3 DBPROPSET dbpropset[2]; 4 DBPROP dbprop[1]; // Property array to initialize the provider. 5 DBPROP sscedbprop[2]; // Property array for SSCE security properties 6 INT i = 0; 7 IDBDataSourceAdmin *pIDBDataSourceAdmin = NULL; 8 IUnknown *pIUnknownSession = NULL; 9 10 //Create an instance of the OLE DB provider. 11 hr = CoCreateInstance( CLSID_SQLSERVERCE_2_0, 0, CLSCTX_INPROC_SERVER, 12 IID_IDBDataSourceAdmin, (void**)& pIDBDataSourceAdmin); 13 if(FAILED(hr)) 14 { 15 goto Exit; 16 } 17 18 //Initialize property structures. 19 VariantInit(&dbprop[0].vValue); 20 for(i = 0;i < sizeof(sscedbprop) / sizeof(sscedbprop[0]);i++) 21 { 22 VariantInit(&sscedbprop[i].vValue); 23 } 24 25 //Specify the property with name of the database. 26 dbprop[0].dwPropertyID = DBPROP_INIT_DATASOURCE; 27 dbprop[0].dwOptions = DBPROPOPTIONS_REQUIRED; 28 dbprop[0].vValue.vt = VT_BSTR; 29 dbprop[0].vValue.bstrVal = SysAllocString(L"数据库名.sdf"); 30 if(NULL == dbprop[0].vValue.bstrVal) 31 { 32 hr = E_OUTOFMEMORY; 33 goto Exit; 34 } 35 36 //Specify the property for encryption. 37 sscedbprop[0].dwPropertyID = DBPROP_SSCE_ENCRYPTDATABASE; 38 sscedbprop[0].dwOptions = DBPROPOPTIONS_REQUIRED; 39 sscedbprop[0].vValue.vt = VT_BOOL; 40 sscedbprop[0].vValue.boolVal = VARIANT_TRUE; 41 42 //Specify the password. 43 sscedbprop[1].dwPropertyID = DBPROP_SSCE_DBPASSWORD; 44 sscedbprop[1].dwOptions = DBPROPOPTIONS_REQUIRED; 45 sscedbprop[1].vValue.vt = VT_BSTR; 46 sscedbprop[1].vValue.bstrVal = SysAllocString(L"数据库密码"); 47 if(NULL == sscedbprop[1].vValue.bstrVal) 48 { 49 hr = E_OUTOFMEMORY; 50 goto Exit; 51 } 52 53 //Initialize the property sets. 54 dbpropset[0].guidPropertySet = DBPROPSET_DBINIT; 55 dbpropset[0].rgProperties = dbprop; 56 dbpropset[0].cProperties = sizeof(dbprop)/sizeof(dbprop[0]); 57 58 dbpropset[1].guidPropertySet = DBPROPSET_SSCE_DBINIT ; 59 dbpropset[1].rgProperties = sscedbprop; 60 dbpropset[1].cProperties = sizeof(sscedbprop)/sizeof(sscedbprop[0]); 61 62 //Create and initialize the database. 63 hr = pIDBDataSourceAdmin->CreateDataSource(sizeof(dbpropset) / sizeof(dbpropset[0]),dbpropset,NULL,IID_IUnknown,&pIUnknownSession); 64 if(FAILED(hr)) 65 { 66 goto Exit; 67 } 68 //At this point, the new encrypted database is created. 69 70 Exit: 71 // Do cleanup tasks here. 72 73 return;
Accessing Password-protected Databases Use the DBPROP_SSCE_DBPASSWORD property in the DBPROPSET_SSCE_DBINIT provider-specific property set to specify this property.
注：
一：注意每次操作SQL CE前都Close一次，因为SQLCE2.0只支持一个连接
二：检测数据库里是否存在某个表用：select table_name from Information_Schema.Tables
三：SQL CE 2.0 不支持存储过程、触发器等，都要用SQL来实现
四：从XML转换过来的时间要转换一下： DateTime dtConvert = DateTime.Parse(xmlTable.ChildNodes[0].InnerXml); dtConvert.ToString("G");
五：SQL CE的字段类型和SQL Server的不一样，具体见SQLCE帮助文档
六：SQL CE不支持Distict 、top 等函数，Distinct可以用GroupBy来实现