刷新Oracle表 [英] Refresh Oracle table

问题描述

使用下面的代码，我添加了列：

 public void AlterTable_AddColumn（OracleConnection连接，字符串tblName，字符串colName）{
 DataTable table = GetOracleDataTable（connection ，select * from，tblName）; 
 DataColumnCollection columns = table.Columns; 
 
 if（！columns.Contains（colName））{
 string s =Alter table+ tblName.ToUpper（）+Add（+ colName +VARCHAR2（500）） ; 
使用（OracleCommand cmd = new OracleCommand（s，connection））{
 cmd.ExecuteNonQuery（）; 
} 
} 
 connection.Close（）; 
} 
 

添加1个新列（此处称为Column1）后，代码重复添加另一列（Column2）。在这一步中，我查看了变量：列，其中列出了除刚刚添加的Column1之外的所有列名。为了刷新包含所有更新的列/行信息的表，如何刷新表？在这段代码中，我在插入新列后加载了数据表（请参阅DataTable table = ...）。我也尝试了connection.Close（）然后连接.Open（），但没有效果。很高兴听取您的解决方案的建议。谢谢。

解决方案

我修改了以下代码：

  public   void  AlterTable_AddColumn（OracleConnection连接，DataTable tbl， string  colName）{
  //   DataTable table = GetOracleDataTable（connection，select * from，tblName）;  
 DataColumnCollection columns = tbl.Columns;  //   table.Columns;  
 
  if （！columns.Contains（colName））{
  string  s =  更改表 + tbl.TableName.ToUpper（）+  添加（ + colName +   VARCHAR2（500））; 
 使用（OracleCommand cmd =  new  OracleCommand（s，connection））{
 cmd.ExecuteNonQuery（）; 
  //   System.Windows.Forms.MessageBox.Show（table changed）;  
} 
 tbl.Columns.Add（colName， typeof （ string ）） ; 
 tbl.ColumnChanged + =  new  DataColumnChangeEventHandler（Column_Changed）; 
 tbl.AcceptChanges（）; 
} 
 connection.Close（）; 
} 
 私有 静态  void  Column_Changed（ object  sender，DataColumnChangeEventArgs e）{
}  //  无用 
 

然后，错误就解决了。但是，我实际上对Oracle的insert和datatable更新都做了。我知道这有点多余。如果您有更好的想法，请分享。感谢。

Using the code below, I add columns:

public void AlterTable_AddColumn(OracleConnection connection, string tblName, string colName)  {
    DataTable table = GetOracleDataTable(connection, "select * from ", tblName);
    DataColumnCollection columns = table.Columns;

    if (!columns.Contains(colName))    {
        string s = "Alter table " + tblName.ToUpper() + " Add ( " + colName + " VARCHAR2(500) ) ";
        using (OracleCommand cmd = new OracleCommand(s, connection))  {
            cmd.ExecuteNonQuery();
        }
    }
    connection.Close();
}

After adding 1 new column (termed Column1 here), the code iterated for adding another column (Column2). In this step, I viewed variable: columns, which listed all of the column names except for Column1 that was just added. In order to refresh the table with all of the updated columns/rows information, how can the table be refreshed? In this piece of code, I erloaded the datatable after inserting a new column (see DataTable table = ...). I also tried connection.Close() and then connection.Open(), but not effective. Will be glad to listen to your advisory for the solution. Thanks.

解决方案

I revised the code as below:

public void AlterTable_AddColumn(OracleConnection connection, DataTable tbl, string colName)   {
    //DataTable table = GetOracleDataTable(connection, "select * from ", tblName);
    DataColumnCollection columns = tbl.Columns;  // table.Columns;

    if (!columns.Contains(colName))    {
        string s = "Alter table " + tbl.TableName.ToUpper() + " Add ( " + colName + " VARCHAR2(500) ) ";
        using (OracleCommand cmd = new OracleCommand(s, connection))    {
            cmd.ExecuteNonQuery();
            //System.Windows.Forms.MessageBox.Show("Table altered");
        }
        tbl.Columns.Add(colName, typeof(string));
        tbl.ColumnChanged += new DataColumnChangeEventHandler(Column_Changed);
        tbl.AcceptChanges();
    }
    connection.Close();
}
private static void Column_Changed(object sender, DataColumnChangeEventArgs e)   {
}    // useless

Then, the bug is solved. However, I actually did on both Oracle's insert and datatable update. I know it somehow redundant. If you have a betgter idea, please share. Thanks.

这篇关于刷新Oracle表的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！