package com.lianxi;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class Test {
public static void main(String[] args) throws Exception {
// TODO Auto-generated method stub
Class.forName("com.mysql.jdbc.Driver");
Connection conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/books","root","tiger");
Statement st=conn.createStatement();
ResultSet rs=st.executeQuery("select * from tb_user");
while(rs.next()){
System.out.print(rs.getInt(1));
System.out.print(rs.getString(2));
System.out.print(rs.getString(3));
System.out.println(rs.getString(4));
}
rs.close();
st.close();
conn.close();
}
}

然后一直提示我错误

Unknown database 'books'

可是我明明有啊，我就不明白了，快疯了 

赠与我所有园豆以表敬意