//(0).全表记录
mysql> select * from computer_stu;
+------+------+-------+
| id   | name | score |
+------+------+-------+
| 1001 | Lily |    85 |
| 1002 | Tom  |    91 |
| 1003 | Jim  |    87 |
| 1004 | Aric |    77 |
| 1005 | Lucy |    65 |
| 1006 | Andy |    99 |
| 1007 | Ada  |    85 |
| 1008 | Jeck |    70 |
+------+------+-------+
8 rows in set (0.00 sec)
 
//(1).查询以特定字符或字符串开头的记录
mysql> select * from computer_stu where name regexp '^L';
+------+------+-------+
| id   | name | score |
+------+------+-------+
| 1001 | Lily |    85 |
| 1005 | Lucy |    65 |
+------+------+-------+
2 rows in set (0.00 sec)
 
//(2).查询以特定字符或字符串结尾的记录
mysql> select * from computer_stu where name regexp 'y$';
+------+------+-------+
| id   | name | score |
+------+------+-------+
| 1001 | Lily |    85 |
| 1005 | Lucy |    65 |
| 1006 | Andy |    99 |
+------+------+-------+
3 rows in set (0.00 sec)
 
//(3).用符号"."来代替字符串中的任意一个字符
mysql> select * from computer_stu where name regexp '^L..y$';
+------+------+-------+
| id   | name | score |
+------+------+-------+
| 1001 | Lily |    85 |
| 1005 | Lucy |    65 |
+------+------+-------+
2 rows in set (0.00 sec)
//其中^L表示以字母L开头，两个"."表示两个任意字符，y$表示以字母y结尾
 
//(4).匹配指定字符中的任意一个
mysql> select * from computer_stu where name regexp '[ci]';
+------+------+-------+
| id   | name | score |
+------+------+-------+
| 1001 | Lily |    85 |
| 1003 | Jim  |    87 |
| 1004 | Aric |    77 |
| 1005 | Lucy |    65 |
| 1008 | Jeck |    70 |
+------+------+-------+
5 rows in set (0.00 sec)
//使用方括号可以指定集合的区间。[a-z]表示a~z的所有字母(mysql字段大小写不敏感)，[0-9]表示从0~9的所有数字，[a-z0-9]表示包含所有的字母和数字。
 
//(5).匹配指定字符以外的字符
mysql> select * from computer_stu where name regexp '[^a-w0-9]';
+------+------+-------+
| id   | name | score |
+------+------+-------+
| 1001 | Lily |    85 |
| 1005 | Lucy |    65 |
| 1006 | Andy |    99 |
+------+------+-------+
3 rows in set (0.00 sec)
 
//(6).匹配指定字符串
mysql> select * from computer_stu where name regexp 'il|dy';
+------+------+-------+
| id   | name | score |
+------+------+-------+
| 1001 | Lily |    85 |
| 1006 | Andy |    99 |
+------+------+-------+
2 rows in set (0.00 sec)
 
//(7).使用"*"和"+"来匹配多个字符
mysql> select * from computer_stu where name regexp 'i*m';
+------+------+-------+
| id   | name | score |
+------+------+-------+
| 1002 | Tom  |    91 |
| 1003 | Jim  |    87 |
+------+------+-------+
2 rows in set (0.00 sec)
mysql> select * from computer_stu where name regexp 'i+m';
+------+------+-------+
| id   | name | score |
+------+------+-------+
| 1003 | Jim  |    87 |
+------+------+-------+
1 row in set (0.00 sec)
 
//(8).使用{M}或者{M,N}来制定字符串连续出现的次数
mysql> insert into computer_stu values(1009,'aaabb',85),(1010,'aabbc',79),(1011,'abccc',98);
Query OK, 3 rows affected (0.01 sec)
Records: 3  Duplicates: 0  Warnings: 0
mysql> select * from computer_stu where name regexp 'a{3}';
+------+-------+-------+
| id   | name  | score |
+------+-------+-------+
| 1009 | aaabb |    85 |
+------+-------+-------+
1 row in set (0.00 sec)
mysql> select * from computer_stu where name regexp 'a{2,3}';
+------+-------+-------+
| id   | name  | score |
+------+-------+-------+
| 1009 | aaabb |    85 |
| 1010 | aabbc |    79 |
+------+-------+-------+
2 rows in set (0.00 sec)

mysql> /*执行不带group by的select语句*/
mysql> select * from employee;
+-----+------+------+-----+-----+--------------+
| num | d_id | name | age | sex | homeaddr     |
+-----+------+------+-----+-----+--------------+
|   1 | 1001 | 张三 |  26 | 男  | 北京市海淀区 |
|   2 | 1001 | 李四 |  24 | 女  | 北京市昌平区 |
|   3 | 1002 | 王五 |  25 | 男  | 湖南长沙市   |
|   4 | 1004 | Aric |  15 | 男  | England      |
+-----+------+------+-----+-----+--------------+
4 rows in set (0.00 sec)
 
mysql> /*单独使用group by分组*/
mysql> select * from employee group by sex;
+-----+------+------+-----+-----+--------------+
| num | d_id | name | age | sex | homeaddr     |
+-----+------+------+-----+-----+--------------+
|   2 | 1001 | 李四 |  24 | 女  | 北京市昌平区 |
|   1 | 1001 | 张三 |  26 | 男  | 北京市海淀区 |
+-----+------+------+-----+-----+--------------+
2 rows in set (0.00 sec)
 
mysql> /*group by与group_concat()函数一起使用*/
mysql> select sex,group_concat(name) from employee group by sex;
+-----+--------------------+
| sex | group_concat(name) |
+-----+--------------------+
| 女  | 李四               |
| 男  | 张三,王五,Aric     |
+-----+--------------------+
2 rows in set (0.01 sec)
 
mysql> /*group by与集合函数一起使用*/
mysql> select sex,count(num),avg(age) from employee group by sex;
+-----+------------+----------+
| sex | count(num) | avg(age) |
+-----+------------+----------+
| 女  |          1 |  24.0000 |
| 男  |          3 |  22.0000 |
+-----+------------+----------+
2 rows in set (0.00 sec)
 
mysql> /*group by与having一起使用*/
mysql> select sex,count(sex) from employee group by sex having count(num)>=3;
+-----+------------+
| sex | count(num) |
+-----+------------+
| 男  |          3 |
+-----+------------+
1 row in set (0.00 sec)
 
mysql> select sex,avg(age),count(num) from employee group by sex having count(num)>=3 or avg(age)>23;
+-----+----------+------------+
| sex | avg(age) | count(num) |
+-----+----------+------------+
| 女  |  24.0000 |          1 |
| 男  |  22.0000 |          3 |
+-----+----------+------------+
2 rows in set (0.00 sec)
/*having条件表达式与where条件表达式一样，都是用来限制显示的。having作用于分组后的记录，用于选择满足条件的组；where作用于表或视图，是表和视图的查询条件。*/
 
mysql> /*按多个字段分组*/
mysql> select * from employee group by d_id,sex;
+-----+------+------+-----+-----+--------------+
| num | d_id | name | age | sex | homeaddr     |
+-----+------+------+-----+-----+--------------+
|   2 | 1001 | 李四 |  24 | 女  | 北京市昌平区 |
|   1 | 1001 | 张三 |  26 | 男  | 北京市海淀区 |
|   3 | 1002 | 王五 |  25 | 男  | 湖南长沙市   |
|   4 | 1004 | Aric |  15 | 男  | England      |
+-----+------+------+-----+-----+--------------+
4 rows in set (0.00 sec)
 
mysql> insert into employee values(null,1001,'aiml',26,'男','北京市海淀区'
Query OK, 1 row affected (0.00 sec)
 
mysql> select * from employee group by d_id,sex;
+-----+------+------+-----+-----+--------------+
| num | d_id | name | age | sex | homeaddr     |
+-----+------+------+-----+-----+--------------+
|   2 | 1001 | 李四 |  24 | 女  | 北京市昌平区 |
|   1 | 1001 | 张三 |  26 | 男  | 北京市海淀区 |
|   3 | 1002 | 王五 |  25 | 男  | 湖南长沙市   |
|   4 | 1004 | Aric |  15 | 男  | England      |
+-----+------+------+-----+-----+--------------+
4 rows in set (0.00 sec)
 
mysql> /*group by与with rollup一起使用*/
mysql> select sex,count(num) from employee group by sex with rollup;
+-----+------------+
| sex | count(num) |
+-----+------------+
| 女  |          1 |
| 男  |          4 |
| NULL |          5 |
+-----+------------+
3 rows in set (0.00 sec)
/*在记录最后加上了一条新的纪录，该记录count(num)列的值是上面分组值的总和。*/

package src;
import java.awt.*;
 
import javax.swing.*;
 
public class GridLayoutDemo extends JFrame {
 
	private static final long serialVersionUID = 1L;
 
	public GridLayoutDemo(){
		setSize(400,300);
		setTitle("网格式布局Demo");
		Toolkit kit = Toolkit.getDefaultToolkit();
		Dimension screenSize = kit.getScreenSize();
		int x=(screenSize.width-400)/2;
		int y=(screenSize.height-300)/2;
		setLocation(x,y);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}
 
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		GridLayoutDemo frame = new GridLayoutDemo();
 
		frame.applyComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT);	//按钮按照从右向左方向排列
		Container contentPane = frame.getContentPane();
		contentPane.setLayout(new GridLayout(2,3));
		JButton jbt1 = new JButton("按钮1");
		contentPane.add(jbt1);
		JButton jbt2 = new JButton("按钮2");
		contentPane.add(jbt2);
		JButton jbt3 = new JButton("按钮3");
		contentPane.add(jbt3);
		JButton jbt4 = new JButton("按钮4");
		contentPane.add(jbt4);
		JButton jbt5 = new JButton("按钮5");
		contentPane.add(jbt5);
		JButton jbt6 = new JButton("按钮6");
		contentPane.add(jbt6);
		JButton jbt7 = new JButton("按钮7");
		contentPane.add(jbt7);
		JButton jbt8 = new JButton("按钮8");
		contentPane.add(jbt8);
 
        frame.setVisible(true);
	}
 
}

import java.awt.Button;
import java.awt.ComponentOrientation;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Toolkit;
 
import javax.swing.JFrame;
import javax.swing.JPanel;
 
/**
 * @author Aiml
 *
 */
public class FlowLayoutDemo extends JFrame {
 
	/**
	 *
	 */
	private static final long serialVersionUID = 1L;
 
	public FlowLayoutDemo(){
 
		setSize(400,300);
		setTitle("流式布局Demo");
		Toolkit kit = Toolkit.getDefaultToolkit();
		Dimension screenSize = kit.getScreenSize();
		int x=(screenSize.width-400)/2;
		int y=(screenSize.height-300)/2;
		setLocation(x,y);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);		
 
		/**
		 * 创建一个JPanel面板
		 */
		JPanel jpa = new JPanel();
 
		/**
		 * 设置窗口中全部组件按从右向左的顺序排列
		 */
		jpa.applyComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT);
 
		/**
		 * 无参的构造函数，居中对齐，水平和垂直间隙是 5 个像素。
		 * 当使用该构造函数的时候，与不写setLayout()函数同样效果。
		 */
	//	jpa.setLayout(new FlowLayout());
 
		/**
		 * 带对齐方式的构造函数，按指定的对齐方式对齐按钮，水平和垂直间隙是 5 个像素。
		 */
	//	jpa.setLayout(new FlowLayout(FlowLayout.RIGHT));
 
		/**
		 * 带对齐方式和水平、树枝间隙参数的构造函数，按指定的对齐方式对其按钮，
		 * 并且按钮水平间隙10像素，竖直间隙20像素
		 */
		jpa.setLayout(new FlowLayout(FlowLayout.LEFT,10,20));		
 
        for(int i = 1; i <= 20; i++){
        	jpa.add(new Button("按钮"+i));
        }
 
        Container c = this.getContentPane();
        c.add(jpa);
	}
 
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		FlowLayoutDemo frame = new FlowLayoutDemo();
        frame.setVisible(true);
	}
}

import java.awt.*;
import javax.swing.JFrame;
 
/**
 * @author Aiml
 *
 */
public class BorderLayoutDemo extends JFrame {
 
	/**
	 *
	 */
	private static final long serialVersionUID = 1L;
 
	public BorderLayoutDemo(){
		setSize(400,300);
		setTitle("边框式布局Demo");
		Toolkit kit = Toolkit.getDefaultToolkit();
		Dimension screenSize = kit.getScreenSize();
		int x=(screenSize.width-400)/2;
		int y=(screenSize.height-300)/2;
		setLocation(x,y);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}
 
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		BorderLayoutDemo frame = new BorderLayoutDemo();
 
		Button bn = new Button("北部区域");
		Button bs = new Button("南部区域");
        Button bw = new Button("西部区域");
        Button be = new Button("东部区域");
        Button bc = new Button("中部区域");
 
        frame.add(bn,BorderLayout.NORTH);
        frame.add(bs,BorderLayout.SOUTH);
        frame.add(bw,BorderLayout.WEST);
        frame.add(be,BorderLayout.EAST);
        frame.add(bc,BorderLayout.CENTER);
 
        frame.setVisible(true);
	}
}