import java.sql.Connection;  

import java.sql.DriverManager;  

import java.sql.ResultSet;  

  

  

import com.mysql.jdbc.Statement;  

  

  

public class MySQLDao {  

 public static void main(String[] args) {  

try {  

Class.forName("com.mysql.jdbc.Driver");  

Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "root");  

Statement sta = (Statement) conn.createStatement(ResultSet.CONCUR_READ_ONLY, ResultSet.TYPE_SCROLL_INSENSITIVE);  

String sql = "select * from homework";  

ResultSet rs  =sta.executeQuery(sql);  

rs.last();  

System.out.println("行数:"+rs.getRow());  

//如果后面需要遍历  

rs.first();//将指针移动到第一行  

//第二种方法:  

int count=1;//由于rs.first()已经在第一个位置了,而下面的循环又调用了next(),所以此处count从1开始  

while(rs.next()){  

count++;  

}  

System.out.println("行数:"+count);  

//第三种方法:  

sql = "select count(*) from homework";  

rs = sta.executeQuery(sql);  

rs.next();  

int row = rs.getInt(1);  

System.out.println("行数:"+row);  

conn.close();  

} catch (Exception e) {  

e.printStackTrace();  

}  

  

}  

}