JDBC连接DB2、Oracle、MySQL、PostgreSQL

转贴自 http://www.cnblogs.com/tivan/articles/1268211.html



JDBC连接DB2、Oracle、MySQL、PostgreSQL，并取得当前时间得实用代码

package   com.terac.util;
import   java.sql.Connection;
import   java.sql.DriverManager;
import   java.sql.ResultSet;
import   java.sql.Statement;
public   class   DBTest   {
public   static   void   main(String[]   args)   {
try   {
String   user   =   "user";
String   password   =   "password";
String   driver   =   "COM.ibm.db2.jdbc.net.DB2Driver";
//"oracle.jdbc.driver.OracleDriver";
//"com.mysql.jdbc.Driver";
//"org.postgresql.Driver";
String   url   =   "jdbc:db2://localhost/a";
//"jdbc:oracle:thin:@localhost:1521:a";
//"jdbc:mysql://localhost/a";
//"jdbc:postgresql://localhost:5740/a";
String   sql   =   "SELECT   current   timestamp   FROM   sysibm.sysdummy1";
//"SELECT   sysdate   FROM   dual";
//"SELECT   now()";
//"SELECT   current_timestamp";
Class.forName(driver).newInstance();
Connection   c   =   DriverManager.getConnection(url,   user,   password);
Statement   stmt   =   c.createStatement();
ResultSet   rs   =   stmt.executeQuery(sql);
while   (rs.next())   {
System.out.println(rs.getString(1));
}
}   catch   (Exception   e)   {
e.printStackTrace();
}
}
}

1:建立、启动oracle数据库

2：在Tomcat中建立oracle驱动程序

oracle JDBC驱动程序的位置：oracle/ora90/jdbc/lib/classes12.jar

将此驱动程序拷贝到Tomcat5.5/common/lib下

此时Tomcat就可以连接到oracle驱动程序

3：连接操作数据库：

<%@ page contentType="text/html;charset=gb2312"%>

<%@ page import="java.sql.*"%>

<%--

使用JDBC连接Oracle数据库

使用MLDN数据库

用户名：scott

密码：tiger

--%>

<%!

String DBDRIVER = "oracle.jdbc.driver.OracleDriver" ;//驱动

String DBURL = "jdbc:oracle:thin:@localhost:1521:mldn" ;//1521是端口，mldn是数据源

String DBUSER = "scott" ;

String DBPASSWORD = "tiger" ;

Connection conn = null ;

Statement stmt = null ;

%>

<%

try

{

Class.forName(DBDRIVER) ;

// 连接时必须填写用户名及密码

conn = DriverManager.getConnection(DBURL,DBUSER,DBPASSWORD) ;

// 创建表的SQL语句

String sql = "CREATE TABLE mldntab (name varchar(20))" ;

stmt = conn.createStatement() ;

stmt.executeUpdate(sql) ;

stmt.close() ;

conn.close() ;

}

catch(Exception e)

{

out.println(e) ;

}

%>