JDBC的操作

 Oracle数据库连接：

import java.sql.*;
public class TestJDBC {

    public static void main(String[] args) throws Exception {
        Class.forName("oracle.jdbc.OracleDriver");
        Connection conn=DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:orcl","scott","tigger");
        Statement stmt = conn.createStatement();
        ResultSet rs = stmt.executeQuery("select * from emp");
        while(rs.next()) {
            System.out.println(rs.getString("deptno"));
        }
        rs.close();
        stmt.close();
        conn.close();
    }

}

 MySQL：

select user,host,password from mysql.user;

通过JDBC链接MySQL数据库

import java.sql.*;

public class TestJDBC {

    public static void main(String[] args) {
        try {
            Class.forName("com.mysql.jdbc.Driver").newInstance();
        } catch (Exception ex) {
            // handle the error
        }
        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;
        try {
            conn = DriverManager.getConnection("jdbc:mysql://localhost/mydata?"
                    + "user=root&password=root");
            stmt = conn.createStatement();
            rs = stmt.executeQuery("select * from dept");
            while (rs.next()) {
                System.out.println(rs.getString("loc"));
            }

        } catch (SQLException ex) {
            // handle any errors
            System.out.println("SQLException: " + ex.getMessage());
            System.out.println("SQLState: " + ex.getSQLState());
            System.out.println("VendorError: " + ex.getErrorCode());
        } finally {
            // it is a good idea to release
            // resources in a finally{} block
            // in reverse-order of their creation
            // if they are no-longer needed
            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException sqlEx) {
                } // ignore

                rs = null;
            }
            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException sqlEx) {
                } // ignore

                stmt = null;
            }
        }

    }

}