关于在ORACLE里修改NULL值的问题（在线急等）

Question

DBF文件?
你用什么倒的?是用EXP?

Answer 1

我是用JAVA写了一个下载并生成DBF文件的程序。
源码如下package com.zhang.download;import com.zhang.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class CreateDbfDwjbxx extends javax.servlet.http.HttpServlet { public void doGet(HttpServletRequest req, HttpServletResponse res)
throws ServletException, java.io.IOException {
long startTime = System.currentTimeMillis();
ResultSet rs = null;
Statement stmt = null;
Connection con = null;
SqlBean dbfWriteBean = new SqlBean();
String dwdm = req.getParameter("dwdm");
Convert convert = new Convert();
// 构造生成年审下发表的查询语句
String selectSqlStr =
"SELECT * FROM  AA001 WHERE AAB001='" + dwdm + "'";
// 用拷贝文件的方法来生成新的DBF数据文件的结构 FileCopy.copy(
"c:\\download\\DWJBXX.dbf",
"c:\\download\\D" + dwdm + ".DBF"); try {
Class.forName("com.hxtt.sql.dbf.DBFDriver");
String url = "jdbc:DBF:/c:\\download";
//Change "../dbffiles" to yourdbfdir
con = DriverManager.getConnection(url, "", "");
stmt = con.createStatement();
String deleteSqlStr = "DELETE FROM D" + dwdm;
stmt.executeUpdate(deleteSqlStr);
} catch (Exception e) {
System.out.println("ERROR ON INIT DBF DRIVER : " + e.getMessage());
} try {
// 查询出将要下发的数据
rs = dbfWriteBean.executeQuery(selectSqlStr); while (rs.next()) {
// 插入一行新的数据
String insertSqlStr =
"INSERT INTO D"
+ dwdm
+ "  VALUES("
+ dwdm
+ ",'"
+ rs.getString("AAB002")
+ "','"
+ rs.getString("AAB003")
+ "','"
+ rs.getString("AAB004")
+ "','"
+ rs.getString("AAB005")
+ "','"
+ rs.getString("AAB006")
+ "','"
+ rs.getString("AAB007")
+ "','"
+ rs.getString("AAB008")
+ "','"
+ rs.getString("AAB009")
+ "','"
+ rs.getString("AAB010")
+ "',"
+ rs.getDate("AAB011")
+ ","
+ rs.getDate("AAB012")
+ ",'"
+ rs.getString("AAB013")
+ "',"
+ rs.getDate("AAB014")
+ ",'"
+ rs.getString("AAB015")
+ "','"
+ rs.getString("AAB016")
+ "','"
+ rs.getString("AAB017")
+ "','"
+ rs.getString("AAB018")
+ "','"
+ rs.getString("AAB019")
+ "','"
+ rs.getString("AAB020")
+ "','"
+ rs.getString("AAB021")
+ "','"
+ rs.getString("AAB022")
+ "','"
+ rs.getString("AAB023")
+ "','"
+ rs.getString("AAB024")
+ "','"
+ rs.getString("AAB025")
+ "','"
+ rs.getString("AAB026")
+ "','"
+ rs.getString("AAB027")
+ "','"
+ rs.getString("AAB028")
+ "','"
+ rs.getString("AAB029")
+ "','"
+ rs.getString("AAB030")
+ "','"
+ rs.getString("AAB031")
+ "','"
+ rs.getString("AAB032")
+ "','"
+ rs.getString("AAB033")
+ "','"
+ rs.getString("AAB034")
+ "','"
+ rs.getString("AAB035")
+ "','"
+ rs.getString("AAB036")
+ "',"
+ rs.getDate("AAB037")
+ ","
+ rs.getDate("AAB038")
+ ",'"
+ rs.getString("AAB039")
+ "','"
+ rs.getString("AAB040")
+ "',"
+ rs.getInt("AAB041")
+ ","
+ rs.getInt("AAB042")
+ ","
+ rs.getInt("AAB043")
+ ","
+ rs.getInt("AAB044")
+ ",'"
+ rs.getString("AAB045")
+ "','"
+ rs.getString("AAB046")
+ "','"
+ rs.getString("AAB047")
+ "')"; stmt.executeUpdate(insertSqlStr);
System.out.println(insertSqlStr);
Thread.sleep(1000);
} } catch (Exception e) {
System.out.println("ERROR ON INSERT DBF : " + e.getMessage());
} finally { try {
rs.close();
stmt.close();
con.close();
dbfWriteBean.closeConnection(); } catch (Exception e) {
System.out.println("ERROR ON CLOSE STMT "); }
} long endTime = System.currentTimeMillis();
System.out.println((endTime - startTime) + "ms");
res.sendRedirect(
"com.zhang.download.Download?downloadFile=D" + dwdm + ".DBF");
/*System.out.println("--");
ServletContext context = getServletContext();
RequestDispatcher rd =
context.getRequestDispatcher(
"/servlet/com.zhang.download.Download?downloadFile=D" + dwdm + ".DBF");
rd.forward(req, res);*/
} // servlet的gopost方法
public void doPost(HttpServletRequest req, HttpServletResponse res)
throws ServletException, java.io.IOException {
doGet(req, res);
}}

Answer 2

能不能完整的告诉我，如果用NVL函数我应该怎么使用，完整的语句应该怎么写？

Answer 3

如果是NULL值转为串'NULL'
select NVL(to_char(Column1),'NULL') from table1；
如果是NULL值转为0
select NVL(to_number(column1),0) from table1;