如何把BMP文件输入数据库？

[hello_wyq]

不知道如何写SQL语句，请网友帮个忙，多谢！

[ggyy]

对于SQL中的TEXT、IMAGE、MEMO字段的存取，可以采用下列程序：

BLOB字段的读取：

TBlobSTream* TemplateStream;

char* TempPlatePtr;

TemplateStream=new TBlobStream((TBlobField*)WebQuery->FieldByName

("SearchTem"),bmReadWrite);

TemplatePtr= new char[TemplateStream->Size];

TemplateStream->Read(TemplatePtr, TemplateStream->Size);

　

BLOB字段的写入：

TBlobSTream* TemplateStream;

char* TempPlatePtr;

　

TemplateStream=new TBlobStream((TBlobField*)WebQuery->FieldByName

("SearchTem"),bmReadWrite);

TemplatePtr= new char[TemplateStream->Size];

TemplateStream->Write(TemplatePtr, TemplateStream->Size);

　

________________________________________________________________

补充:

获得字段的大小用函数datalength

SQL Server端要作一点设置:

By default, WRITETEXT is a nonlogged operation. This means that

text or image data is not logged when it is written into the database.

To use WRITETEXT in its default, nonlogged state,

//注意!!

the system administrator must use the sp_dboption system stored

procedure to set select into/bulkcopy,

//

which allows nonlogged data to be inserted.

　

做了试验,直接写SQL语句好象不行.

____________________________________________________________________

一些注意事项和一个例子

在写入时:

(1)如果使用的是TTable,则要将其ReadOnly属性先置为false,然后调用Edit函数;

(2)如果使用的是TQuery,则要将其RequestLive属性先置为true,然后调用Edit函数;

使得TTable(TQuery)是可写的.

　

下面是一个使用TQuery往content表(主键file_id)中插入一条记录的例子,

script为一个BLOB字段:

TBlobStream *pScriptStream;

//插入一条记录

strSQL1="insert into content(file_id,script,key_image) values('";

strSQL1=strSQL1+m_szFileID+"',null,null)";

dmStoryEditor->qryExec->SQL->Clear();

dmStoryEditor->qryExec->SQL->Add(strSQL1);

dmStoryEditor->qryExec->ExecSQL();

dmStoryEditor->qryExec->Close();

//整理要写入的Blob数据

LockMemories(NewsScript);

NewsScript.GetEdition(NewsScript.m_ScriptHead.byteEditionNum);

NewsScript.m_pScript=(BYTE *)GlobalLock(NewsScript.m_hScript);

if(NewsScript.m_pScript!=NULL)

{

//再将刚插入的记录读出来,使该Query与该条记录关联

strSQL1="select file_id,script from content where file_id='"+

m_szFileID+"'";

//允许该Query写

dmStoryEditor->qryExec->RequestLive=true;

dmStoryEditor->qryExec->SQL->Clear();

dmStoryEditor->qryExec->SQL->Add(strSQL1);

dmStoryEditor->qryExec->Open();

dmStoryEditor->qryExec->First();

//将该Query置为可写

dmStoryEditor->qryExec->Edit();

pScriptStream=new TBlobStream((TBlobField*)dmStoryEditor->

qryExec->FieldByName("script"),bmReadWrite);

pScriptStream->Write(NewsScript.m_pScript,

NewsScript.m_lScriptRealSize);

dmStoryEditor->qryExec->Post();

dmStoryEditor->qryExec->RequestLive=false;

delete pScriptStream;

}

GlobalUnlock(NewsScript.m_hScript);

UnLockMemories(NewsScript);

[hello_wyq]

to ggyy(原始社会好,原始社会好!):
thx

[hello_wyq]

我比较的弱，最好具体一些：）