java 之数据库

1，统计有多少记录

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;

public class k1
{
	public static void mb_show(ResultSet r)
	{		
		try 
		{
			r.last();
			System.out.println("数据表共有 "+r.getRow()+"行.");
		}
		catch (Exception e)
		{
			System.out.println("异常"+e.getMessage());
		}
	}
	public static void main(String args[])
	{
		try 
		{
			Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
			Connection c=DriverManager.getConnection ("jdbc:odbc:studentDatabase");
			Statement s=c.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE);
			ResultSet r=s.executeQuery("select * from 学生成绩");
			mb_show(r);
			s.close();
			c.close();
		}
		catch (Exception e)
		{
		}
	}
}

2，实现插入、删除、修改操作

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;

public class c
{
	public static void main(String args[])
	{
		try{
			Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
		    Connection c=DriverManager.getConnection ("jdbc:odbc:studentDatabase");
		    Statement s=c.createStatement();
		  //  s.executeUpdate("ALTER TABLE 学生成绩 "+"add 性别 char(10)");
		   // s.executeUpdate("alter table 学生成绩 "+"drop column xingming");
		    s.executeUpdate("update 学生成绩 set chengji ='99' where xuehao='2' ");
		    System.out.println("sdfs");
		    s.close();
		    c.close();
		    System.out.println("sdf");
		}
		catch (Exception e)
		{
			System.out.println("yichang"+e.getMessage());
		}
	}
}