BFILE编程示例

BFILE

/*创建环境句柄、到数据库的连接 和 statement*/
Environment *env = Environment::createEnvironment();
Connection *conn = env->createConnection(user,pwd,link);
Statement *stmt = conn->createStatement();

string csql = "create table testbfile(id INT ,bf BFILE)";
string dsql = "drop table testbfile";
string isql = "insert into occi_test values (:bl)";
string test_sql ="select count(*) from occi_test where bl is null";
ResultSet* rs = NULL;

//创建表
stmt->execute(dsql);
stmt->execute(csql);

// 创建目录
string createDir;
buffer = getcwd(NULL, 0);
createDir = "create or replace directory BFILEDIR as '" + buffer + "';";
m_stmt->executeQuery(createDir);

// 创建文件
ofstream fout("testbfile.txt",ios::out | ios::trunc);
fout << "唧唧复唧唧，木兰当户织。\n";
fout.close();

// 插入数据
stmt->setSQL(insert_sql);
stmt->setInt(1, 1016);
Bfile file(conn);
file.setName("BFILEDIR", "testbfile.txt");
stmt->setBfile(2, file);
stmt->execute();
conn->commit();

// 查询
while (rs->next())
{
      char* buffer;
      string dir, filename;
      int len = 0;
      int amt = 0;
      int readlen = 0;
      Bfile file = rs->getBfile(1);
      if (!file.isOpen())
      {
              //打开文件
              file.open();
      }

      len = file.length();
      amt = len / 10;
      buffer = new char[amt+1];
      for (int i = 1; i <len; i+= readlen)
      {
              readlen = file.read(amt, (unsigned char*)buffer, amt+1, i);
              cout << buffer << endl;
      }
}
stmt->closeResultSet(rs);
m_stmt->executeQuery("drop table testbfile");
remove("testbfile.txt");
m_stmt->execute(dsql);

/*释放statement、数据库连接 和 环境句柄*/
conn->terminateStatement(stmt);
env->terminateConnection(conn);
Environment::terminateEnvironment(env);