BCB实现BLOB字段的读写[VC/C++编程]

关于SQL中的TEXT、IMAGE、MEMO字段的存取,可以采取下列程序:

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);

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增补:

得到字段的大小用函数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.

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