Question

我想连接到多个数据库，并希望通过这些连接运行某些查询，但它无法正常工作。

            string source = "10.0.0.0";
            string user = "abc";
            string password="abc";

             DataTable dt = new DataTable();

            for (int i = 0; i < dt.Rows.Count; i++)
            {


                string source = dt.Rows[i][2].ToString();
                string user = dt.Rows[i][1].ToString();
                int password = Convert.ToInt32(user) + 111;

                OracleConnection conn = new OracleConnection("Data Source =  " + source + ": 1521/rms; User id = " + user + "; Password=" + password + ";");
                conn.Open();

                OracleCommand cmd = new OracleCommand(" SELECT SUM(AI_TRN) FROM tr_rtl where DC_DY_BSN = '06-04-2016'and mall like '%" + Mallname.Text + "%' ", conn);
                cmd.ExecuteNonQuery();
                OracleDataAdapter oda = new OracleDataAdapter(cmd);
                oda.Fill(dt);
                dataGridView1.DataSource = dt;
                conn.Close();


                label1.Text = source;



            }

        }

        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);

抱歉，我发布了错误的代码

Answer 1

您可能需要做的是遍历连接列表并使用所有结果填充一个数据表。这是一个例子：

List<OracleConnections> Connections = new List<OracleConnections>();
DataTable FinalResults = new DataTable();

foreach (var Connection in Connections)
{
   using (Connection)
   {
      DataTable TemporaryTable = new DataTable();
      Connection.Open();
      OracleCommand Command = new OracleCommand("SomeCommandText", Connection);
      OracleDataAdapter Adapter = new OracleDataAdapter(Command);
      Adapter.Fill(TemporaryTable);
      FinalResults.Merge(TemporaryTable);
   }
}

这应该在一个最终表（结果）中为您提供每个数据库/连接的所有结果，或者如果每个连接中的列/数据不同，您可以执行数据集。

更新以解释上面列出的评论。

string Source = "10.0.0.0";
string User = "abc";
string Password = "abc";

DataTable dt = new DataTable();
// Remove this or use another reference (different table), you just created the table ^, it has no rows. -> "for (int i = 0; i < dt.Rows.Count; i++)"

打开与多个数据库的连接

1 个答案: