这段程序为什么编译没通过 Connection 是一个局部变量? 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 ("jdbc.odbc.jdbcodbc.aaa","system","manager");这里好象不对吧!!你到底使用JDBC还是ODBC!!! 给你个例子import java.sql.*;public class aa { public static void main(String args[]) { String url="jdbc:oracle:thin:@128.128.128.60:1521:orcl"; Connection con; String createString; createString = "select * from test"; Statement stmt; ResultSet rs = null; try { Class.forName("oracle.jdbc.driver.OracleDriver"); } catch(java.lang.ClassNotFoundException e) { e.printStackTrace(); System.err.println(e.getMessage()); } try { con = DriverManager.getConnection(url, "system", "manager"); stmt = con.createStatement(); rs = stmt.executeQuery(createString); while (rs.next()) { System.out.println(rs.getString(1) + "\n"); } stmt.close(); con.close(); } catch(SQLException ex) { System.err.println("SQLException: " + ex.getMessage()); } }} cn是一个局部变量,也就是说只能在{ Connection conn=DriverManager.getConnection("jdbc.odbc.jdbcodbc.aaa","system","manager");}把你的Statement stmt=conn.createStatement(); String query="SELECT NAME FROM CESHI"; ResultSet r=stmt.executeQuery(query);while(r.next()){String n=r.getString("NAME");System.out.println(n+" ");}拿到cn定义的地方就可以了 1. variable scope2. url=jdbc.odbc.aaa try{Connection conn=DriverManager.getConnection //这里的conn只能在这个块可见。("jdbc.odbc.jdbcodbc.aaa","system","manager");}catch (SQLException ex){ sDebug+="连接失败"+ex.getMessage();}try{Statement stmt=conn.createStatement();String query="SELECT NAME FROM CESHI";ResultSet r=stmt.executeQuery(query);while(r.next()){String n=r.getString("NAME");System.out.println(n+" ");}}catch(SQLException ee) {sDebug+="查询失败"+ee.getMessage();}} try{Connection conn=DriverManager.getConnection //这里的conn只能在这个块可见。("jdbc.odbc.jdbcodbc.aaa","system","manager");}catch (SQLException ex){ sDebug+="连接失败"+ex.getMessage();}try{Statement stmt=conn.createStatement();String query="SELECT NAME FROM CESHI";ResultSet r=stmt.executeQuery(query);while(r.next()){String n=r.getString("NAME");System.out.println(n+" ");}}catch(SQLException ee) {sDebug+="查询失败"+ee.getMessage();}}为什么不输出结果 关于Class里面的field初始化问题 速算24 如何增加运算符优先级 fileReader读出的行顺序不对怎么解决? 抽象类有什么用 怎样写这个String的replaceAll()方法? 一个出错问题!!!急急急急急急!!! java 中字符串中包含”“,该怎么表达 有上过尚学堂的朋友吗? 24点扑克牌游戏编程算法详解 急!weblogic中如何配置WEB application? 有没有办法让一个Java程序只能有一个实例在运行 AWT中怎么取得被点click的控件对象名? 就是想知道click了哪个控件
这里好象不对吧!!
你到底使用JDBC还是ODBC!!!
import java.sql.*;public class aa {
public static void main(String args[]) {
String url="jdbc:oracle:thin:@128.128.128.60:1521:orcl";
Connection con;
String createString;
createString = "select * from test";
Statement stmt;
ResultSet rs = null;
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
} catch(java.lang.ClassNotFoundException e) {
e.printStackTrace(); System.err.println(e.getMessage());
} try {
con = DriverManager.getConnection(url, "system", "manager");
stmt = con.createStatement();
rs = stmt.executeQuery(createString);
while (rs.next()) {
System.out.println(rs.getString(1) + "\n");
}
stmt.close();
con.close(); } catch(SQLException ex) {
System.err.println("SQLException: " + ex.getMessage());
}
}
}
{
Connection conn=DriverManager.getConnection("jdbc.odbc.jdbcodbc.aaa","system","manager");
}
把你的
Statement stmt=conn.createStatement();
String query="SELECT NAME FROM CESHI";
ResultSet r=stmt.executeQuery(query);
while(r.next())
{
String n=r.getString("NAME");
System.out.println(n+" ");
}拿到cn定义的地方就可以了
2. url=jdbc.odbc.aaa
Connection conn=DriverManager.getConnection //这里的conn只能在这个块可见。("jdbc.odbc.jdbcodbc.aaa","system","manager");
}catch (SQLException ex){
sDebug+="连接失败"+ex.getMessage();
}
try{
Statement stmt=conn.createStatement();
String query="SELECT NAME FROM CESHI";
ResultSet r=stmt.executeQuery(query);
while(r.next())
{
String n=r.getString("NAME");
System.out.println(n+" ");
}
}
catch(SQLException ee)
{sDebug+="查询失败"+ee.getMessage();}
}
Connection conn=DriverManager.getConnection //这里的conn只能在这个块可见。("jdbc.odbc.jdbcodbc.aaa","system","manager");
}catch (SQLException ex){
sDebug+="连接失败"+ex.getMessage();
}
try{
Statement stmt=conn.createStatement();
String query="SELECT NAME FROM CESHI";
ResultSet r=stmt.executeQuery(query);
while(r.next())
{
String n=r.getString("NAME");
System.out.println(n+" ");
}
}
catch(SQLException ee)
{sDebug+="查询失败"+ee.getMessage();}
}为什么不输出结果