求助：ODAC无法提交修改，提示“LOB LOCATOR SHOULD BE INITED.”

[ahaisong]

表：CREATE TABLE TBL_BLOB(
BLOB_ID CHAR(10),
BLOB_DESC BLOB)
CREATE UNIQUE INDEX IDX_BLOB_ID ON TBL_BLOB (BLOB_ID ASC)

在执行下面代码的 tmpOraQuery->Post() 时出错，提示“LOB LOCATOR SHOULD BE INITED.”请帮忙解决！

TOraQuery* tmpOraQuery = new TOraQuery(this);
try{
tmpOraQuery->Session = OraSession1;
tmpOraQuery->Close();
tmpOraQuery->SQL->Text = "SELECT * FROM TBL_BLOB WHERE BLOB_ID = '" + Edit1->Text + "' FOR UPDATE ";
tmpOraQuery->SQLUpdate->Text = " UPDATE TBL_BLOB SET BLOB_ID = :BLOB_ID, BLOB_DESC = :BLOB_DESC WHERE BLOB_ID = '" + Edit1->Text + "' ";
tmpOraQuery->Open();
tmpOraQuery->First();
tmpOraQuery->Edit();
tmpOraQuery->FieldByName("BLOB_ID")->AsString = Edit2->Text;
tmpBlobField = (TBlobField*)tmpOraQuery->FieldByName("BLOB_DESC");
tmpBlobField->Clear();
tmpBlobField->LoadFromFile(".\\A.TXT");
try{
tmpOraQuery->Post();
}
catch(...){
ShowMessage("插入Blob失败！");
tmpOraQuery->Close();
}
}
__finally{
tmpOraQuery->Close();
delete tmpOraQuery;
}

[xizhouhawk]

tmpOraQuery->FieldByName("BLOB_ID")->AsString = Edit2->Text;
tmpBlobField = (TBlobField*)tmpOraQuery->FieldByName("BLOB_DESC");
在这两句前好像要加一个准备的句子具体我忘记了，好像是prepare();
你查一查吧

[ahaisong]

我发现:
如果 BLOB_DESC 字段中有内容的话, 执行能成功,
否则就会报错: Lob locator should be inited.

[ahaisong]

另外还有一个问题: 如何用 ODAC 批量更新 BLOB 字段？

[ahaisong]

我的关于 "Lob locator should be inited" 的解决方法:
先插入一个字符到 Blob 字段，然后用流去更新 Blob 字段

tmpOraQuery->Close();
tmpOraQuery->SQL->Text = "INSERT INTO TBL_BLOB(BLOB_ID, BLOB_DESC) VALUES ('" + Edit1->Text + "', 'A') ";
tmpOraQuery->ExecSQL();

tmpOraQuery2->Close();
tmpOraQuery2->ReadOnly = false;
tmpOraQuery2->SQL->Text = " SELECT * FROM TBL_BLOB WHERE BLOB_ID = '"
+ Edit1->Text + "' FOR UPDATE ";
tmpOraQuery2->SQLUpdate->Text = " UPDATE TBL_BLOB SET BLOB_DESC = :BLOB_DESC
WHERE BLOB_ID = '" + Edit1->Text + "' ";
tmpOraQuery2->Open();
tmpOraQuery2->First();
tmpOraQuery2->Edit();
((TBlobField*)tmpOraQuery2->FieldByName("BLOB_DESC"))->LoadFromFile(".\\A.TXT");
tmpOraQuery2->Post();