使用C＃，是否可以使System.Data.OleDb处理特殊字符？

Question

I have an existing C# project that reads a text file and loads it into an Oracle DB using System.Data.OleDb as provider. Problem is that if the file has upper ascii characters (eg ÀÑÓ, non-breaking space) it always generates an error when it tries to load it into Oracle:

Error is: OLEDBConnection Command Parameter data value could not be converted for reasons other than sign mismatch or data overflow .

Our Oracle can accept upper ascii characters (insert via SQL*PLUS works fine), it is System.Data.OleDb that is having issue.

Anyone know if there is a setting to change this? Can't believe that that only accepts AZ-0-9. Looked thru a ll documentation but couldn't find anything.

If it can't, how do you let OLEDB know to escape the character. Tired putting \\ in the file before special characters, but it still errors with same message.

Answer 1

Usually this is possible without any problem... since you don't provide much detail only some general pointers:

• Database Charset should be set to AL32UTF8
  you can check this by executing SELECT parameter, value FROM nls_database_parameters WHERE parameter = 'NLS_CHARACTERSET';
• Client Charset should be set to AL32UTF8
  see for this registry settings for NLS_LANG
• Columns should be VARCHAR2
• Connection string should include OLEDB.NET=True
  for further reference see http://download.oracle.com/docs/cd/B28359_01/win.111/b28431/using.htm#i1017221

Other points to check could be OS and Client and OLEDB versions... some have bugs or strange behaviour...

Answer 2

You may have to use HEX conversions. For example %c4 is Ä.

Try that and let me know if that works. Here are the conversion functions you can use.

internal String convertAsciiTextToHex(String asciiText)
{
StringBuilder sBuffer = new StringBuilder();
for (int i = 0; i < asciiText.Length; i++)
{
    sBuffer.Append(Convert.ToInt32(asciiText[i]).ToString("x"));
}
return sBuffer.ToString().ToUpper();
}

internal String convertHexToAsciiText(String hexString)
{
    StringBuilder sb = new StringBuilder();

 for (int i = 0; i < hexString.Length; i += 2)
 {
   string hs = hexString.Substring(i, 2);
   sb.Append(Convert.ToChar(Convert.ToUInt32(hs, 16)));
 }
    String ascii = sb.ToString();
    return ascii;
}

Answer 3

您的数据类型和参数类型是nvarchar2吗？