{"id":11421,"date":"2025-06-12T00:03:02","date_gmt":"2025-06-11T16:03:02","guid":{"rendered":"https:\/\/egonlin.com\/?p=11421"},"modified":"2025-06-12T16:25:57","modified_gmt":"2025-06-12T08:25:57","slug":"%e5%a4%9a%e8%a1%a8%e6%9f%a5%e8%af%a2","status":"publish","type":"post","link":"https:\/\/egonlin.com\/?p=11421","title":{"rendered":"\u591a\u8868\u67e5\u8be2"},"content":{"rendered":"<h3>\u4e00 \u4ecb\u7ecd<\/h3>\n<p>\u672c\u8282\u4e3b\u9898<\/p>\n<ul>\n<li>\u591a\u8868\u8fde\u63a5\u67e5\u8be2<\/li>\n<li>\u590d\u5408\u6761\u4ef6\u8fde\u63a5\u67e5\u8be2<\/li>\n<li>\u5b50\u67e5\u8be2<\/li>\n<\/ul>\n<p>\u51c6\u5907\u8868<\/p>\n<p>\u8868department\u4e0eemployee<\/p>\n<pre>#\u5efa\u8868\r\ncreate table department(\r\nid int,\r\nname varchar(20) \r\n);\r\n\r\ncreate table employee(\r\nid int primary key auto_increment,\r\nname varchar(20),\r\nsex enum('male','female') not null default 'male',\r\nage int,\r\ndep_id int\r\n);\r\n\r\n#\u63d2\u5165\u6570\u636e\r\ninsert into department values\r\n(200,'\u6280\u672f'),\r\n(201,'\u4eba\u529b\u8d44\u6e90'),\r\n(202,'\u9500\u552e'),\r\n(203,'\u8fd0\u8425');\r\n\r\ninsert into employee(name,sex,age,dep_id) values\r\n('egon','male',18,200),\r\n('alex','female',48,201),\r\n('wupeiqi','male',38,201),\r\n('yuanhao','female',28,202),\r\n('liwenzhou','male',18,200),\r\n('jingliyang','female',18,204)\r\n;\r\n\r\n\r\n#\u67e5\u770b\u8868\u7ed3\u6784\u548c\u6570\u636e\r\nmysql&gt; desc department;\r\n+-------+-------------+------+-----+---------+-------+\r\n| Field | Type | Null | Key | Default | Extra |\r\n+-------+-------------+------+-----+---------+-------+\r\n| id | int(11) | YES | | NULL | |\r\n| name | varchar(20) | YES | | NULL | |\r\n+-------+-------------+------+-----+---------+-------+\r\n\r\nmysql&gt; desc employee;\r\n+--------+-----------------------+------+-----+---------+----------------+\r\n| Field | Type | Null | Key | Default | Extra |\r\n+--------+-----------------------+------+-----+---------+----------------+\r\n| id | int(11) | NO | PRI | NULL | auto_increment |\r\n| name | varchar(20) | YES | | NULL | |\r\n| sex | enum('male','female') | NO | | male | |\r\n| age | int(11) | YES | | NULL | |\r\n| dep_id | int(11) | YES | | NULL | |\r\n+--------+-----------------------+------+-----+---------+----------------+\r\n\r\nmysql&gt; select * from department;\r\n+------+--------------+\r\n| id | name |\r\n+------+--------------+\r\n| 200 | \u6280\u672f |\r\n| 201 | \u4eba\u529b\u8d44\u6e90 |\r\n| 202 | \u9500\u552e |\r\n| 203 | \u8fd0\u8425 |\r\n+------+--------------+\r\n\r\nmysql&gt; select * from employee;\r\n+----+------------+--------+------+--------+\r\n| id | name | sex | age | dep_id |\r\n+----+------------+--------+------+--------+\r\n| 1 | egon | male | 18 | 200 |\r\n| 2 | alex | female | 48 | 201 |\r\n| 3 | wupeiqi | male | 38 | 201 |\r\n| 4 | yuanhao | female | 28 | 202 |\r\n| 5 | liwenzhou | male | 18 | 200 |\r\n| 6 | jingliyang | female | 18 | 204 |\r\n+----+------------+--------+------+--------+<\/pre>\n<h3>\u4e8c \u591a\u8868\u8fde\u63a5\u67e5\u8be2<\/h3>\n<div class=\"cnblogs_code\">\n<pre>#\u91cd\u70b9\uff1a\u5916\u94fe\u63a5\u8bed\u6cd5\r\n\r\nSELECT \u5b57\u6bb5\u5217\u8868\r\n    FROM \u88681 INNER|LEFT|RIGHT JOIN \u88682\r\n    ON \u88681.\u5b57\u6bb5 = \u88682.\u5b57\u6bb5;<\/pre>\n<\/div>\n<p><strong>1 \u4ea4\u53c9\u8fde\u63a5\uff1a\u4e0d\u9002\u7528\u4efb\u4f55\u5339\u914d\u6761\u4ef6\u3002\u751f\u6210\u7b1b\u5361\u5c14\u79ef<\/strong><\/p>\n<div class=\"cnblogs_code\">\n<pre>mysql&gt; select * from employee,department;\r\n+----+------------+--------+------+--------+------+--------------+\r\n| id | name       | sex    | age  | dep_id | id   | name         |\r\n+----+------------+--------+------+--------+------+--------------+\r\n|  1 | egon       | male   |   18 |    200 |  200 | \u6280\u672f         |\r\n|  1 | egon       | male   |   18 |    200 |  201 | \u4eba\u529b\u8d44\u6e90     |\r\n|  1 | egon       | male   |   18 |    200 |  202 | \u9500\u552e         |\r\n|  1 | egon       | male   |   18 |    200 |  203 | \u8fd0\u8425         |\r\n|  2 | alex       | female |   48 |    201 |  200 | \u6280\u672f         |\r\n|  2 | alex       | female |   48 |    201 |  201 | \u4eba\u529b\u8d44\u6e90     |\r\n|  2 | alex       | female |   48 |    201 |  202 | \u9500\u552e         |\r\n|  2 | alex       | female |   48 |    201 |  203 | \u8fd0\u8425         |\r\n|  3 | wupeiqi    | male   |   38 |    201 |  200 | \u6280\u672f         |\r\n|  3 | wupeiqi    | male   |   38 |    201 |  201 | \u4eba\u529b\u8d44\u6e90     |\r\n|  3 | wupeiqi    | male   |   38 |    201 |  202 | \u9500\u552e         |\r\n|  3 | wupeiqi    | male   |   38 |    201 |  203 | \u8fd0\u8425         |\r\n|  4 | yuanhao    | female |   28 |    202 |  200 | \u6280\u672f         |\r\n|  4 | yuanhao    | female |   28 |    202 |  201 | \u4eba\u529b\u8d44\u6e90     |\r\n|  4 | yuanhao    | female |   28 |    202 |  202 | \u9500\u552e         |\r\n|  4 | yuanhao    | female |   28 |    202 |  203 | \u8fd0\u8425         |\r\n|  5 | liwenzhou  | male   |   18 |    200 |  200 | \u6280\u672f         |\r\n|  5 | liwenzhou  | male   |   18 |    200 |  201 | \u4eba\u529b\u8d44\u6e90     |\r\n|  5 | liwenzhou  | male   |   18 |    200 |  202 | \u9500\u552e         |\r\n|  5 | liwenzhou  | male   |   18 |    200 |  203 | \u8fd0\u8425         |\r\n|  6 | jingliyang | female |   18 |    204 |  200 | \u6280\u672f         |\r\n|  6 | jingliyang | female |   18 |    204 |  201 | \u4eba\u529b\u8d44\u6e90     |\r\n|  6 | jingliyang | female |   18 |    204 |  202 | \u9500\u552e         |\r\n|  6 | jingliyang | female |   18 |    204 |  203 | \u8fd0\u8425         |\r\n+----+------------+--------+------+--------+------+--------------+<\/pre>\n<\/div>\n<p><strong>2 \u5185\u8fde\u63a5\uff1a\u53ea\u8fde\u63a5\u5339\u914d\u7684\u884c<\/strong><\/p>\n<div class=\"cnblogs_code\">\n<pre>#\u627e\u4e24\u5f20\u8868\u5171\u6709\u7684\u90e8\u5206\uff0c\u76f8\u5f53\u4e8e\u5229\u7528\u6761\u4ef6\u4ece\u7b1b\u5361\u5c14\u79ef\u7ed3\u679c\u4e2d\u7b5b\u9009\u51fa\u4e86\u6b63\u786e\u7684\u7ed3\u679c\r\n#department\u6ca1\u6709204\u8fd9\u4e2a\u90e8\u95e8\uff0c\u56e0\u800cemployee\u8868\u4e2d\u5173\u4e8e204\u8fd9\u6761\u5458\u5de5\u4fe1\u606f\u6ca1\u6709\u5339\u914d\u51fa\u6765\r\nmysql&gt; select employee.id,employee.name,employee.age,employee.sex,department.name from employee inner join department on employee.dep_id=department.id; \r\n+----+-----------+------+--------+--------------+\r\n| id | name      | age  | sex    | name         |\r\n+----+-----------+------+--------+--------------+\r\n|  1 | egon      |   18 | male   | \u6280\u672f         |\r\n|  2 | alex      |   48 | female | \u4eba\u529b\u8d44\u6e90     |\r\n|  3 | wupeiqi   |   38 | male   | \u4eba\u529b\u8d44\u6e90     |\r\n|  4 | yuanhao   |   28 | female | \u9500\u552e         |\r\n|  5 | liwenzhou |   18 | male   | \u6280\u672f         |\r\n+----+-----------+------+--------+--------------+\r\n\r\n#\u4e0a\u8ff0sql\u7b49\u540c\u4e8e\r\nmysql&gt; select employee.id,employee.name,employee.age,employee.sex,department.name from employee,department where employee.dep_id=department.id;<\/pre>\n<\/div>\n<p><strong>3 \u5916\u94fe\u63a5\u4e4b\u5de6\u8fde\u63a5\uff1a\u4f18\u5148\u663e\u793a\u5de6\u8868\u5168\u90e8\u8bb0\u5f55<\/strong><\/p>\n<div class=\"cnblogs_code\">\n<pre>#\u4ee5\u5de6\u8868\u4e3a\u51c6\uff0c\u5373\u627e\u51fa\u6240\u6709\u5458\u5de5\u4fe1\u606f\uff0c\u5f53\u7136\u5305\u62ec\u6ca1\u6709\u90e8\u95e8\u7684\u5458\u5de5\r\n#\u672c\u8d28\u5c31\u662f\uff1a\u5728\u5185\u8fde\u63a5\u7684\u57fa\u7840\u4e0a\u589e\u52a0\u5de6\u8fb9\u6709\u53f3\u8fb9\u6ca1\u6709\u7684\u7ed3\u679c\r\nmysql&gt; select employee.id,employee.name,department.name as depart_name from employee left join department on employee.dep_id=department.id;\r\n+----+------------+--------------+\r\n| id | name       | depart_name  |\r\n+----+------------+--------------+\r\n|  1 | egon       | \u6280\u672f         |\r\n|  5 | liwenzhou  | \u6280\u672f         |\r\n|  2 | alex       | \u4eba\u529b\u8d44\u6e90     |\r\n|  3 | wupeiqi    | \u4eba\u529b\u8d44\u6e90     |\r\n|  4 | yuanhao    | \u9500\u552e         |\r\n|  6 | jingliyang | NULL         |\r\n+----+------------+--------------+<\/pre>\n<\/div>\n<p><strong>4 \u5916\u94fe\u63a5\u4e4b\u53f3\u8fde\u63a5\uff1a\u4f18\u5148\u663e\u793a\u53f3\u8868\u5168\u90e8\u8bb0\u5f55<\/strong><\/p>\n<div class=\"cnblogs_code\">\n<pre>#\u4ee5\u53f3\u8868\u4e3a\u51c6\uff0c\u5373\u627e\u51fa\u6240\u6709\u90e8\u95e8\u4fe1\u606f\uff0c\u5305\u62ec\u6ca1\u6709\u5458\u5de5\u7684\u90e8\u95e8\r\n#\u672c\u8d28\u5c31\u662f\uff1a\u5728\u5185\u8fde\u63a5\u7684\u57fa\u7840\u4e0a\u589e\u52a0\u53f3\u8fb9\u6709\u5de6\u8fb9\u6ca1\u6709\u7684\u7ed3\u679c\r\nmysql&gt; select employee.id,employee.name,department.name as depart_name from employee right join department on employee.dep_id=department.id;\r\n+------+-----------+--------------+\r\n| id   | name      | depart_name  |\r\n+------+-----------+--------------+\r\n|    1 | egon      | \u6280\u672f         |\r\n|    2 | alex      | \u4eba\u529b\u8d44\u6e90     |\r\n|    3 | wupeiqi   | \u4eba\u529b\u8d44\u6e90     |\r\n|    4 | yuanhao   | \u9500\u552e         |\r\n|    5 | liwenzhou | \u6280\u672f         |\r\n| NULL | NULL      | \u8fd0\u8425         |\r\n+------+-----------+--------------+<\/pre>\n<\/div>\n<p><strong>5 \u5168\u5916\u8fde\u63a5\uff1a\u663e\u793a\u5de6\u53f3\u4e24\u4e2a\u8868\u5168\u90e8\u8bb0\u5f55<\/strong><\/p>\n<div class=\"cnblogs_code\">\n<pre>\u5168\u5916\u8fde\u63a5\uff1a\u5728\u5185\u8fde\u63a5\u7684\u57fa\u7840\u4e0a\u589e\u52a0\u5de6\u8fb9\u6709\u53f3\u8fb9\u6ca1\u6709\u7684\u548c\u53f3\u8fb9\u6709\u5de6\u8fb9\u6ca1\u6709\u7684\u7ed3\u679c\r\n#\u6ce8\u610f\uff1amysql\u4e0d\u652f\u6301\u5168\u5916\u8fde\u63a5 full JOIN\r\n#\u5f3a\u8c03\uff1amysql\u53ef\u4ee5\u4f7f\u7528\u6b64\u79cd\u65b9\u5f0f\u95f4\u63a5\u5b9e\u73b0\u5168\u5916\u8fde\u63a5\r\nselect * from employee left join department on employee.dep_id = department.id\r\nunion\r\nselect * from employee right join department on employee.dep_id = department.id\r\n;\r\n#\u67e5\u770b\u7ed3\u679c\r\n+------+------------+--------+------+--------+------+--------------+\r\n| id   | name       | sex    | age  | dep_id | id   | name         |\r\n+------+------------+--------+------+--------+------+--------------+\r\n|    1 | egon       | male   |   18 |    200 |  200 | \u6280\u672f         |\r\n|    5 | liwenzhou  | male   |   18 |    200 |  200 | \u6280\u672f         |\r\n|    2 | alex       | female |   48 |    201 |  201 | \u4eba\u529b\u8d44\u6e90     |\r\n|    3 | wupeiqi    | male   |   38 |    201 |  201 | \u4eba\u529b\u8d44\u6e90     |\r\n|    4 | yuanhao    | female |   28 |    202 |  202 | \u9500\u552e         |\r\n|    6 | jingliyang | female |   18 |    204 | NULL | NULL         |\r\n| NULL | NULL       | NULL   | NULL |   NULL |  203 | \u8fd0\u8425         |\r\n+------+------------+--------+------+--------+------+--------------+\r\n\r\n#\u6ce8\u610f union\u4e0eunion all\u7684\u533a\u522b\uff1aunion\u4f1a\u53bb\u6389\u76f8\u540c\u7684\u7eaa\u5f55<\/pre>\n<\/div>\n<h3>\u4e09 \u7b26\u5408\u6761\u4ef6\u8fde\u63a5\u67e5\u8be2<\/h3>\n<div class=\"cnblogs_code\">\n<pre>#\u793a\u4f8b1\uff1a\u4ee5\u5185\u8fde\u63a5\u7684\u65b9\u5f0f\u67e5\u8be2employee\u548cdepartment\u8868\uff0c\u5e76\u4e14employee\u8868\u4e2d\u7684age\u5b57\u6bb5\u503c\u5fc5\u987b\u5927\u4e8e25,\u5373\u627e\u51fa\u5e74\u9f84\u5927\u4e8e25\u5c81\u7684\u5458\u5de5\u4ee5\u53ca\u5458\u5de5\u6240\u5728\u7684\u90e8\u95e8\r\nselect employee.name,department.name from employee inner join department\r\n    on employee.dep_id = department.id\r\n    where age &gt; 25;\r\n\r\n#\u793a\u4f8b2\uff1a\u4ee5\u5185\u8fde\u63a5\u7684\u65b9\u5f0f\u67e5\u8be2employee\u548cdepartment\u8868\uff0c\u5e76\u4e14\u4ee5age\u5b57\u6bb5\u7684\u5347\u5e8f\u65b9\u5f0f\u663e\u793a\r\nselect employee.id,employee.name,employee.age,department.name from employee,department\r\n    where employee.dep_id = department.id\r\n    and age &gt; 25\r\n    order by age asc;<\/pre>\n<\/div>\n<h3>\u56db \u5b50\u67e5\u8be2<\/h3>\n<div class=\"cnblogs_code\">\n<pre>#1\uff1a\u5b50\u67e5\u8be2\u662f\u5c06\u4e00\u4e2a\u67e5\u8be2\u8bed\u53e5\u5d4c\u5957\u5728\u53e6\u4e00\u4e2a\u67e5\u8be2\u8bed\u53e5\u4e2d\u3002\r\n#2\uff1a\u5185\u5c42\u67e5\u8be2\u8bed\u53e5\u7684\u67e5\u8be2\u7ed3\u679c\uff0c\u53ef\u4ee5\u4e3a\u5916\u5c42\u67e5\u8be2\u8bed\u53e5\u63d0\u4f9b\u67e5\u8be2\u6761\u4ef6\u3002\r\n#3\uff1a\u5b50\u67e5\u8be2\u4e2d\u53ef\u4ee5\u5305\u542b\uff1aIN\u3001NOT IN\u3001ANY\u3001ALL\u3001EXISTS \u548c NOT EXISTS\u7b49\u5173\u952e\u5b57\r\n#4\uff1a\u8fd8\u53ef\u4ee5\u5305\u542b\u6bd4\u8f83\u8fd0\u7b97\u7b26\uff1a= \u3001 !=\u3001&gt; \u3001&lt;\u7b49<\/pre>\n<\/div>\n<p><strong>1 \u5e26IN\u5173\u952e\u5b57\u7684\u5b50\u67e5\u8be2<\/strong><\/p>\n<div class=\"cnblogs_code\">\n<pre>#\u67e5\u8be2\u5e73\u5747\u5e74\u9f84\u572825\u5c81\u4ee5\u4e0a\u7684\u90e8\u95e8\u540d\r\nselect id,name from department\r\n    where id in \r\n        (select dep_id from employee group by dep_id having avg(age) &gt; 25);\r\n\r\n#\u67e5\u770b\u6280\u672f\u90e8\u5458\u5de5\u59d3\u540d\r\nselect name from employee\r\n    where dep_id in \r\n        (select id from department where name='\u6280\u672f');\r\n\r\n#\u67e5\u770b\u4e0d\u8db31\u4eba\u7684\u90e8\u95e8\u540d(\u5b50\u67e5\u8be2\u5f97\u5230\u7684\u662f\u6709\u4eba\u7684\u90e8\u95e8id)\r\nselect name from department where id not in (select distinct dep_id from employee);\r\n\r\n<\/pre>\n<p>\uff01\uff01\uff01\u6ce8\u610fnot in<\/p>\n<pre>not in \u65e0\u6cd5\u5904\u7406null\u7684\u503c\uff0c\u5373\u5b50\u67e5\u8be2\u4e2d\u5982\u679c\u5b58\u5728null\u7684\u503c\uff0cnot in\u5c06\u65e0\u6cd5\u5904\u7406\uff0c\u5982\u4e0b\r\n\r\nmysql&gt; select * from emp;\r\n+----+------------+--------+------+--------+\r\n| id | name | sex | age | dep_id |\r\n+----+------------+--------+------+--------+\r\n| 1 | egon | male | 18 | 200 |\r\n| 2 | alex | female | 48 | 201 |\r\n| 3 | wupeiqi | male | 38 | 201 |\r\n| 4 | yuanhao | female | 28 | 202 |\r\n| 5 | liwenzhou | male | 18 | 200 |\r\n| 6 | jingliyang | female | 18 | 204 |\r\n| 7 | xxx | male | 19 | NULL |\r\n+----+------------+--------+------+--------+\r\n7 rows in set (0.00 sec)\r\n\r\nmysql&gt; select * from dep;\r\n+------+--------------+\r\n| id | name |\r\n+------+--------------+\r\n| 200 | \u6280\u672f |\r\n| 201 | \u4eba\u529b\u8d44\u6e90 |\r\n| 202 | \u9500\u552e |\r\n| 203 | \u8fd0\u8425 |\r\n+------+--------------+\r\n4 rows in set (0.00 sec)\r\n\r\n# \u5b50\u67e5\u8be2\u4e2d\u5b58\u5728null\r\nmysql&gt; select * from dep where id not in (select distinct dep_id from emp);\r\nEmpty set (0.00 sec)\r\n\r\n# \u89e3\u51b3\u65b9\u6848\u5982\u4e0b\r\nmysql&gt; select * from dep where id not in (select distinct dep_id from emp where dep_id is not null);\r\n+------+--------+\r\n| id | name |\r\n+------+--------+\r\n| 203 | \u8fd0\u8425 |\r\n+------+--------+\r\n1 row in set (0.00 sec)\r\n\r\nmysql&gt;<\/pre>\n<p><strong>2 \u5e26ANY\u5173\u952e\u5b57\u7684\u5b50\u67e5\u8be2<\/strong><\/p>\n<div class=\"cnblogs_code\">\n<pre>#\u5728 SQL \u4e2d ANY \u548c SOME \u662f\u540c\u4e49\u8bcd\uff0cSOME \u7684\u7528\u6cd5\u548c\u529f\u80fd\u548c ANY \u4e00\u6a21\u4e00\u6837\u3002\r\n\r\n# ANY \u548c IN \u8fd0\u7b97\u7b26\u4e0d\u540c\u4e4b\u59041\r\nANY \u5fc5\u987b\u548c\u5176\u4ed6\u7684\u6bd4\u8f83\u8fd0\u7b97\u7b26\u5171\u540c\u4f7f\u7528\uff0c\u800c\u4e14ANY\u5fc5\u987b\u5c06\u6bd4\u8f83\u8fd0\u7b97\u7b26\u653e\u5728 ANY \u5173\u952e\u5b57\u4e4b\u524d\uff0c\u6240\u6bd4\u8f83\u7684\u503c\u9700\u8981\u5339\u914d\u5b50\u67e5\u8be2\u4e2d\u7684\u4efb\u610f\u4e00\u4e2a\u503c\uff0c\u8fd9\u4e5f\u5c31\u662f ANY \u5728\u82f1\u6587\u4e2d\u6240\u8868\u793a\u7684\u610f\u4e49\r\n\r\n\u4f8b\u5982\uff1a\u4f7f\u7528 IN \u548c\u4f7f\u7528 ANY\u8fd0\u7b97\u7b26\u5f97\u5230\u7684\u7ed3\u679c\u662f\u4e00\u81f4\u7684\r\nselect * from employee where salary = any (\r\nselect max(salary) from employee group by depart_id);\r\n\r\nselect * from employee where salary in (\r\nselect max(salary) from employee group by depart_id);\r\n\r\n\u7ed3\u8bba\uff1a\u4e5f\u5c31\u662f\u8bf4\u201c=ANY\u201d\u7b49\u4ef7\u4e8e IN \u8fd0\u7b97\u7b26\uff0c\u800c\u201c&lt;&gt;ANY\u201d\u5219\u7b49\u4ef7\u4e8e NOT IN \u8fd0\u7b97\u7b26\r\n\r\n# ANY\u548c IN \u8fd0\u7b97\u7b26\u4e0d\u540c\u4e4b\u59042\r\nANY \u8fd0\u7b97\u7b26\u4e0d\u80fd\u4e0e\u56fa\u5b9a\u7684\u96c6\u5408\u76f8\u5339\u914d\uff0c\u6bd4\u5982\u4e0b\u9762\u7684 SQL \u8bed\u53e5\u662f\u9519\u8bef\u7684\r\n\r\nSELECT\r\n*\r\nFROM\r\nT_Book\r\nWHERE\r\nFYearPublished &lt; ANY (2001, 2003, 2005)<\/pre>\n<\/div>\n<p><strong>3 \u5e26ALL\u5173\u952e\u5b57\u7684\u5b50\u67e5\u8be2<\/strong><\/p>\n<div class=\"cnblogs_code\">\n<pre># all\u540cany\u7c7b\u4f3c\uff0c\u53ea\u4e0d\u8fc7all\u8868\u793a\u7684\u662f\u6240\u6709\uff0cany\u8868\u793a\u4efb\u4e00<\/pre>\n<pre>\u67e5\u8be2\u51fa\u90a3\u4e9b\u85aa\u8d44\u6bd4\u6240\u6709\u90e8\u95e8\u7684\u5e73\u5747\u85aa\u8d44\u90fd\u9ad8\u7684\u5458\u5de5=\u300b\u85aa\u8d44\u5728\u6240\u6709\u90e8\u95e8\u5e73\u5747\u7ebf\u4ee5\u4e0a\u7684\u72d7\u5e01\u8d44\u672c\u5bb6\r\nselect * from employee where salary &gt; all (\r\nselect avg(salary) from employee group by depart_id);\r\n\r\n<\/pre>\n<pre>\u67e5\u8be2\u51fa\u90a3\u4e9b\u85aa\u8d44\u6bd4\u6240\u6709\u90e8\u95e8\u7684\u5e73\u5747\u85aa\u8d44\u90fd\u4f4e\u7684\u5458\u5de5=\u300b\u85aa\u8d44\u5728\u6240\u6709\u90e8\u95e8\u5e73\u5747\u7ebf\u4ee5\u4e0b\u7684\u65e0\u4ea7\u9636\u7ea7\u52b3\u82e6\u5927\u4f17\r\nselect * from employee where salary &lt; all (\r\nselect avg(salary) from employee group by depart_id);\r\n\r\n\r\n\r\n\r\n\r\n\u67e5\u8be2\u51fa\u90a3\u4e9b\u85aa\u8d44\u6bd4\u4efb\u610f\u4e00\u4e2a\u90e8\u95e8\u7684\u5e73\u5747\u85aa\u8d44\u4f4e\u7684\u5458\u5de5=\u300b\u85aa\u8d44\u5728\u4efb\u4e00\u90e8\u95e8\u5e73\u5747\u7ebf\u4ee5\u4e0b\u7684\u5458\u5de5\r\nselect * from employee where salary &lt; any ( select avg(salary) from employee group by depart_id);<strong>\u00a0\r\n\r\n<\/strong><\/pre>\n<pre>\u67e5\u8be2\u51fa\u90a3\u4e9b\u85aa\u8d44\u6bd4\u4efb\u610f\u4e00\u4e2a\u90e8\u95e8\u7684\u5e73\u5747\u85aa\u8d44\u9ad8\u7684\u5458\u5de5=\u300b\u85aa\u8d44\u5728\u4efb\u4e00\u90e8\u95e8\u5e73\u5747\u7ebf\u4ee5\u4e0a\u7684\u5458\u5de5<\/pre>\n<pre>select * from employee where salary &gt; any (\r\nselect avg(salary) from employee group by depart_id);<strong>\u00a0<\/strong><\/pre>\n<\/div>\n<p><strong>4 \u5e26\u6bd4\u8f83\u8fd0\u7b97\u7b26\u7684\u5b50\u67e5\u8be2<\/strong><\/p>\n<div class=\"cnblogs_code\">\n<pre>#\u6bd4\u8f83\u8fd0\u7b97\u7b26\uff1a=\u3001!=\u3001&gt;\u3001&gt;=\u3001&lt;\u3001&lt;=\u3001&lt;&gt;\r\n#\u67e5\u8be2\u5927\u4e8e\u6240\u6709\u4eba\u5e73\u5747\u5e74\u9f84\u7684\u5458\u5de5\u540d\u4e0e\u5e74\u9f84\r\nmysql&gt; select name,age from emp where age &gt; (select avg(age) from emp);\r\n+---------+------+\r\n| name | age |\r\n+---------+------+\r\n| alex | 48 |\r\n| wupeiqi | 38 |\r\n+---------+------+\r\n2 rows in set (0.00 sec)\r\n\r\n\r\n#\u67e5\u8be2\u5927\u4e8e\u90e8\u95e8\u5185\u5e73\u5747\u5e74\u9f84\u7684\u5458\u5de5\u540d\u3001\u5e74\u9f84\r\nselect t1.name,t1.age from emp t1\r\ninner join \r\n(select dep_id,avg(age) avg_age from emp group by dep_id) t2\r\non t1.dep_id = t2.dep_id\r\nwhere t1.age &gt; t2.avg_age;<\/pre>\n<\/div>\n<p><strong>5 \u5e26EXISTS\u5173\u952e\u5b57\u7684\u5b50\u67e5\u8be2<\/strong><\/p>\n<p>EXISTS\u5173\u5b57\u952e\u5b57\u8868\u793a\u5b58\u5728\u3002\u5728\u4f7f\u7528EXISTS\u5173\u952e\u5b57\u65f6\uff0c\u5185\u5c42\u67e5\u8be2\u8bed\u53e5\u4e0d\u8fd4\u56de\u67e5\u8be2\u7684\u8bb0\u5f55\u3002<br \/>\n\u800c\u662f\u8fd4\u56de\u4e00\u4e2a\u771f\u5047\u503c\u3002True\u6216False<br \/>\n\u5f53\u8fd4\u56deTrue\u65f6\uff0c\u5916\u5c42\u67e5\u8be2\u8bed\u53e5\u5c06\u8fdb\u884c\u67e5\u8be2\uff1b\u5f53\u8fd4\u56de\u503c\u4e3aFalse\u65f6\uff0c\u5916\u5c42\u67e5\u8be2\u8bed\u53e5\u4e0d\u8fdb\u884c\u67e5\u8be2<\/p>\n<div class=\"cnblogs_code\">\n<pre>#department\u8868\u4e2d\u5b58\u5728dept_id=203\uff0cTure\r\nmysql&gt; select * from employee\r\n    -&gt;     where exists\r\n    -&gt;         (select id from department where id=200);\r\n+----+------------+--------+------+--------+\r\n| id | name       | sex    | age  | dep_id |\r\n+----+------------+--------+------+--------+\r\n|  1 | egon       | male   |   18 |    200 |\r\n|  2 | alex       | female |   48 |    201 |\r\n|  3 | wupeiqi    | male   |   38 |    201 |\r\n|  4 | yuanhao    | female |   28 |    202 |\r\n|  5 | liwenzhou  | male   |   18 |    200 |\r\n|  6 | jingliyang | female |   18 |    204 |\r\n+----+------------+--------+------+--------+\r\n\r\n#department\u8868\u4e2d\u5b58\u5728dept_id=205\uff0cFalse\r\nmysql&gt; select * from employee\r\n    -&gt;     where exists\r\n    -&gt;         (select id from department where id=204);\r\nEmpty set (0.00 sec)<\/pre>\n<\/div>\n<p><strong>5.1 in\u4e0eexists<\/strong><\/p>\n<div class=\"cnblogs_code\">\n<pre>\uff01\uff01\uff01\uff01\uff01\uff01\u5f53in\u548cexists\u5728\u67e5\u8be2\u6548\u7387\u4e0a\u6bd4\u8f83\u65f6\uff0cin\u67e5\u8be2\u7684\u6548\u7387\u5feb\u4e8eexists\u7684\u67e5\u8be2\u6548\u7387\uff01\uff01\uff01\uff01\uff01\uff01<\/pre>\n<pre>==============================exists==============================\r\n# exists\r\nexists\u540e\u9762\u4e00\u822c\u90fd\u662f\u5b50\u67e5\u8be2\uff0c\u540e\u9762\u7684\u5b50\u67e5\u8be2\u88ab\u79f0\u505a\u76f8\u5173\u5b50\u67e5\u8be2\uff08\u5373\u4e0e\u4e3b\u8bed\u53e5\u76f8\u5173\uff09\uff0c\u5f53\u5b50\u67e5\u8be2\u8fd4\u56de\u884c\u6570\u65f6\uff0cexists\u6761\u4ef6\u8fd4\u56detrue\uff0c\r\n\u5426\u5219\u8fd4\u56defalse\uff0cexists\u662f\u4e0d\u8fd4\u56de\u5217\u8868\u7684\u503c\u7684\uff0cexists\u53ea\u5728\u4e4e\u62ec\u53f7\u91cc\u7684\u6570\u636e\u80fd\u4e0d\u80fd\u67e5\u627e\u51fa\u6765\uff0c\u662f\u5426\u5b58\u5728\u8fd9\u6837\u7684\u8bb0\u5f55\u3002\r\n\r\n# \u4f8b\r\n\u67e5\u8be2\u51fa\u90a3\u4e9b\u73ed\u7ea7\u91cc\u6709\u5b66\u751f\u7684\u73ed\u7ea7\r\nselect * from class where exists (select * from stu where stu.cid=class.id)\r\n\r\n# exists\u7684\u6267\u884c\u539f\u7406\u4e3a\uff1a\r\n1\u3001\u4f9d\u6b21\u6267\u884c\u5916\u90e8\u67e5\u8be2\uff1a\u5373select * from class \r\n2\u3001\u7136\u540e\u4e3a\u5916\u90e8\u67e5\u8be2\u8fd4\u56de\u7684\u6bcf\u4e00\u884c\u5206\u522b\u6267\u884c\u4e00\u6b21\u5b50\u67e5\u8be2\uff1a\u5373(select * from stu where stu.cid=class.cid)\r\n3\u3001\u5b50\u67e5\u8be2\u5982\u679c\u8fd4\u56de\u884c\uff0c\u5219exists\u6761\u4ef6\u6210\u7acb\uff0c\u6761\u4ef6\u6210\u7acb\u5219\u8f93\u51fa\u5916\u90e8\u67e5\u8be2\u53d6\u51fa\u7684\u90a3\u6761\u8bb0\u5f55\r\n\r\n==============================in==============================\r\n# in\r\nin\u540e\u8ddf\u7684\u90fd\u662f\u5b50\u67e5\u8be2\uff0cin()\u540e\u9762\u7684\u5b50\u67e5\u8be2 \u662f\u8fd4\u56de\u7ed3\u679c\u96c6\u7684\r\n\r\n# \u4f8b\r\n\u67e5\u8be2\u548c\u6240\u6709\u5973\u751f\u5e74\u9f84\u76f8\u540c\u7684\u7537\u751f\r\nselect * from stu where sex='\u7537' and age in(select age from stu where sex='\u5973')\r\n\r\n# in\u7684\u6267\u884c\u539f\u7406\u4e3a\uff1a\r\nin()\u7684\u6267\u884c\u6b21\u5e8f\u548cexists()\u4e0d\u4e00\u6837,in()\u7684\u5b50\u67e5\u8be2\u4f1a\u5148\u4ea7\u751f\u7ed3\u679c\u96c6,\r\n\u7136\u540e\u4e3b\u67e5\u8be2\u518d\u53bb\u7ed3\u679c\u96c6\u91cc\u53bb\u627e\u7b26\u5408\u8981\u6c42\u7684\u5b57\u6bb5\u5217\u8868\u53bb.\u7b26\u5408\u8981\u6c42\u7684\u8f93\u51fa,\u53cd\u4e4b\u5219\u4e0d\u8f93\u51fa.<\/pre>\n<\/div>\n<p><strong>5.2 not in\u4e0e not exists<\/strong><\/p>\n<div class=\"cnblogs_code\">\n<pre>!!!!!!not exists\u67e5\u8be2\u7684\u6548\u7387\u8fdc\u8fdc\u9ad8\u4e0enot in\u67e5\u8be2\u7684\u6548\u7387\u3002!!!!!!\r\n\r\n==============================not in==============================\r\nnot in()\u5b50\u67e5\u8be2\u7684\u6267\u884c\u987a\u5e8f\u662f\uff1a\r\n\u4e3a\u4e86\u8bc1\u660enot in\u6210\u7acb\uff0c\u5373\u627e\u4e0d\u5230\uff0c\u9700\u8981\u4e00\u6761\u4e00\u6761\u5730\u67e5\u8be2\u8868\uff0c\u7b26\u5408\u8981\u6c42\u624d\u8fd4\u56de\u5b50\u67e5\u8be2\u7684\u7ed3\u679c\u96c6\uff0c\u4e0d\u7b26\u5408\u7684\u5c31\u7ee7\u7eed\u67e5\u8be2\u4e0b\u4e00\u6761\u8bb0\u5f55\uff0c\u76f4\u5230\u628a\u8868\u4e2d\u7684\u8bb0\u5f55\u67e5\u8be2\u5b8c\uff0c\u53ea\u80fd\u67e5\u8be2\u5168\u90e8\u8bb0\u5f55\u624d\u80fd\u8bc1\u660e\uff0c\u5e76\u6ca1\u6709\u7528\u5230\u7d22\u5f15\u3002\r\n                \r\n==============================not exists==============================\r\nnot exists\uff1a\r\n\u5982\u679c\u4e3b\u67e5\u8be2\u8868\u4e2d\u8bb0\u5f55\u5c11\uff0c\u5b50\u67e5\u8be2\u8868\u4e2d\u8bb0\u5f55\u591a\uff0c\u5e76\u6709\u7d22\u5f15\u3002\r\n\u4f8b\u5982:\u67e5\u8be2\u90a3\u4e9b\u73ed\u7ea7\u4e2d\u6ca1\u6709\u5b66\u751f\u7684\u73ed\u7ea7\r\nselect * from class\r\n\r\nwhere not exists\r\n\r\n(select * from student where student.cid = class.cid)\r\n\r\nnot exists\u7684\u6267\u884c\u987a\u5e8f\u662f\uff1a\r\n\u5728\u8868\u4e2d\u67e5\u8be2\uff0c\u662f\u6839\u636e\u7d22\u5f15\u67e5\u8be2\u7684\uff0c\u5982\u679c\u5b58\u5728\u5c31\u8fd4\u56detrue\uff0c\u5982\u679c\u4e0d\u5b58\u5728\u5c31\u8fd4\u56defalse\uff0c\u4e0d\u4f1a\u6bcf\u6761\u8bb0\u5f55\u90fd\u53bb\u67e5\u8be2\u3002<\/pre>\n<\/div>\n<p>\u5e94\u7528-\u51c6\u5907\u6570\u636e<\/p>\n<pre>create database db13;\r\n\r\nuse db13\r\n\r\ncreate table student(\r\n    id int primary key auto_increment,\r\n    name varchar(16)\r\n);\r\n\r\ncreate table course(\r\n    id int primary key auto_increment,\r\n    name varchar(16),\r\n    comment varchar(20)\r\n);\r\n\r\ncreate table student2course(\r\n    id int primary key auto_increment,\r\n    sid int,\r\n    cid int,\r\n    foreign key(sid) references student(id),\r\n    foreign key(cid) references course(id)\r\n);\r\n\r\n\r\ninsert into student(name) values\r\n(\"egon\"),\r\n(\"lili\"),\r\n(\"jack\"),\r\n(\"tom\");\r\n\r\ninsert into course(name,comment) values\r\n(\"\u6570\u636e\u5e93\",\"\u6570\u636e\u4ed3\u5e93\"),\r\n(\"\u6570\u5b66\",\"\u6839\u672c\u5b66\u4e0d\u4f1a\"),\r\n(\"\u82f1\u8bed\",\"\u9e1f\u8bed\u82b1\u9999\");\r\n\r\n\r\ninsert into student2course(sid,cid) values\r\n(1,1),\r\n(1,2),\r\n(1,3),\r\n(2,1),\r\n(2,2),\r\n(3,2);\r\n\r\n<\/pre>\n<pre>\u793a\u4f8b<\/pre>\n<pre># 1\u3001\u67e5\u8be2\u9009\u4fee\u4e86\u6240\u6709\u8bfe\u7a0b\u7684\u5b66\u751fid\u3001name:\uff08\u5373\u8be5\u5b66\u751f\u6839\u672c\u5c31\u4e0d\u5b58\u5728\u4e00\u95e8\u4ed6\u6ca1\u6709\u9009\u7684\u8bfe\u7a0b\u3002\uff09\r\nselect * from student s where not exists\r\n    (select * from course c where not exists\r\n        (select * from student2course sc where sc.sid=s.id and sc.cid=c.id));\r\n\r\n\r\nselect s.name from student as s\r\ninner join student2course as sc\r\non s.id=sc.sid\r\ngroup by s.name \r\nhaving count(sc.id) = (select count(id) from course);\r\n\r\n# 2\u3001\u67e5\u8be2\u6ca1\u6709\u9009\u62e9\u6240\u6709\u8bfe\u7a0b\u7684\u5b66\u751f\uff0c\u5373\u6ca1\u6709\u5168\u9009\u7684\u5b66\u751f\u3002\uff08\u5b58\u5728\u8fd9\u6837\u7684\u4e00\u4e2a\u5b66\u751f\uff0c\u4ed6\u81f3\u5c11\u6709\u4e00\u95e8\u8bfe\u6ca1\u6709\u9009\uff09\r\nselect * from student s where exists\r\n    (select * from course c where not exists\r\n        (select * from student2course sc where sc.sid=s.id and sc.cid=c.id));\r\n\r\n# 3\u3001\u67e5\u8be2\u4e00\u95e8\u8bfe\u4e5f\u6ca1\u6709\u9009\u7684\u5b66\u751f\u3002\uff08\u4e0d\u5b58\u8fd9\u6837\u7684\u4e00\u4e2a\u5b66\u751f\uff0c\u4ed6\u81f3\u5c11\u9009\u4fee\u4e00\u95e8\u8bfe\u7a0b\uff09\r\nselect * from student s where not exists\r\n    (select * from course c where exists\r\n        (select * from student2course sc where sc.sid=s.id and sc.cid=c.id));\r\n\r\n# 4\u3001\u67e5\u8be2\u81f3\u5c11\u9009\u4fee\u4e86\u4e00\u95e8\u8bfe\u7a0b\u7684\u5b66\u751f\u3002\r\nselect * from student s where exists\r\n    (select * from course c where exists\r\n        (select * from student2course sc where sc.sid=s.id and sc.cid=c.id));\r\n\r\n<\/pre>\n<h3><strong>\u7ec3\u4e60\uff1a\u67e5\u8be2\u6bcf\u4e2a\u90e8\u95e8\u6700\u65b0\u5165\u804c\u7684\u90a3\u4f4d\u5458\u5de5<\/strong><\/h3>\n<div id=\"rml_readmorelogin_placeholder\" style=\"position:relative;\"><div id=\"rml_fade_content\" style=\"position: absolute;\r\ntop:-10em;\r\nwidth:100%;\r\nheight:10em;\r\nbackground: -webkit-linear-gradient(rgba(255, 255, 255, 0) 0%,#ffffff 100%);\r\nbackground-image: -moz-linear-gradient(rgba(255, 255, 255, 0) 0%,#ffffff 100%);\r\nbackground-image: -o-linear-gradient(rgba(255, 255, 255, 0) 0%,#ffffff 100%);\r\nbackground-image: linear-gradient(rgba(255, 255, 255, 0) 0%,#ffffff 100%);\r\nbackground-image: -ms-linear-gradient(rgba(255, 255, 255, 0) 0%,#ffffff 100%);\"><\/div><div class=\"wpf-controller aru_rml_from_in_post\" style=\"background-color:#eeeeee;border:5px solid #cce6ff;\" id=\"ARU_ReadMoreLogin_ReadMoreLoginController\"><h2 id=\"Header\">\u67e5\u770b\u66f4\u591a<\/h2><div id=\"Message\"><p>\u8054\u7cfb\u7ba1\u7406\u5458\u5fae\u4fe1tutu19192010\uff0c\u6ce8\u518c\u8d26\u53f7<\/p>\n<\/div><div id=\"StatusBarHeader\"><\/div><form id=\"ARU_ReadMoreLogin_ReadMoreLoginController\"><input name=\"post_id\" value=\"11421\" type=\"hidden\"\/><input name=\"_init_callback\" value=\"InitLogin\" type=\"hidden\"\/><input name=\"post_id\" value=\"11421\" type=\"hidden\"\/><input name=\"rt_ype\" value=\"1\" type=\"hidden\"\/><input name=\"nonce\" value=\"f591e7a9c2\" type=\"hidden\"\/><input name=\"_wpnonce\" value=\"2d1dcda414\" type=\"hidden\"\/><input name=\"_controller\" value=\"ARU_ReadMoreLogin\\ReadMoreLoginController\" type=\"hidden\"\/><input name=\"_proxy_controller\" value=\"ARU_ReadMoreLogin\\ReadMoreLoginController\" type=\"hidden\"\/><input name=\"_view\" value=\"ARU_ReadMoreLogin\\ReadMoreLoginView\" type=\"hidden\"\/><table class=\"wpf-table-placeholder\"><tbody class=\"wpf-table-placeholder\"><tr class=\"wpf-table-placeholder\"><td class=\"wpf-table-placeholder-input\" width=\"400px\"><table class=\"wpf-table-placeholder\"><tbody class=\"wpf-table-placeholder\"><tr class=\"wpf-table-placeholder\"><th class=\"wpf-table-placeholder-input\"><label class=\"wpf-label\">Username:<\/label><\/th><\/tr><tr class=\"wpf-table-placeholder\"><td class=\"wpf-table-placeholder-input\"><input class=\"regular-text text_input\" name=\"username\" value=\"\" type=\"text\"\/><\/td><\/tr><tr class=\"wpf-table-placeholder\"><th class=\"wpf-table-placeholder-input\"><label class=\"wpf-label\">Password:<\/label><\/th><\/tr><tr class=\"wpf-table-placeholder\"><td class=\"wpf-table-placeholder-input\"><input class=\"regular-text text_input\" name=\"password\" value=\"\" type=\"password\"\/><\/td><\/tr><\/tbody><\/table><p class=\"wpf-table-placeholder submit\"><button class=\"wp_plugin_framework_ajax_button\" type=\"button\" style=\"background-color:#4D90FE;;color:#ffffff;;border:1px solid #3079ed;\" name=\"_event\" value=\"ButtonLogin\">Log in<\/button><\/p><\/td><td class=\"wpf-table-placeholder-input\"><\/td><\/tr><\/tbody><\/table><\/form><div id=\"ButtonStartRegister\"><a href=\"https:\/\/egonlin.com\/wp-login.php?action=register\">Register<\/a><\/div><div id=\"Link1\"><a href=\"https:\/\/egonlin.com\/wp-login.php?action=lostpassword\">Forgotten username or password?<\/a><\/div><div id=\"StatusBarFooter\"><\/div><\/div><\/div><div id=aru_remaining_content><\/div>","protected":false},"excerpt":{"rendered":"<p>\u4e00 \u4ecb\u7ecd \u672c\u8282\u4e3b\u9898 \u591a\u8868\u8fde\u63a5\u67e5\u8be2 \u590d\u5408\u6761\u4ef6\u8fde\u63a5\u67e5\u8be2 \u5b50\u67e5\u8be2 \u51c6\u5907\u8868 \u8868department\u4e0eemployee  [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/11421"}],"collection":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=11421"}],"version-history":[{"count":7,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/11421\/revisions"}],"predecessor-version":[{"id":11435,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/11421\/revisions\/11435"}],"wp:attachment":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=11421"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=11421"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=11421"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}