如何为SQL查询编写JOIN语句？

Question

如何为SQL查询编写JOIN语句？

4

我需要一个从IP地址获取国家名称的功能。

我需要在我的网站上展示每个独立访客的国家。（之前，我曾提出类似的问题，但现在我已经改变了方法。）

我期望得到的输出如下所示：

Country Visited | No. of Times
_______________________________
United States   |   482
Korea           |   213
Pakistan        |   123

....

输出显示，有482个独立访客来自美国，213个来自韩国等等。

为了达成这个目的，我将这个任务分为两部分，第一部分是获取所有独立用户的IP地址，第二部分是在两个包含国家/IP信息的表中搜索以获得国家。

然后，我们根据顶部输出表格汇总数据。我将展示我为每个部分编写的查询。下面，我展示了使用的表的结构和示例数据。

第一部分 - 获取我的网站上的独立访客

SELECT a.uid, a.hostname, COUNT( * ) AS times
FROM login_activity a
WHERE a.uid =83
GROUP BY a.hostname
ORDER BY times

这显示的输出结果如下。它意味着ID为83的用户访问该网站有80次独立访问：

uid  | hostname         | times
-------------------------------------
83   |  157.191.122.36  | 80

我本应该获得每个IP的点击次数，但不知道为何无法实现。

第二部分 - 根据IP查找所在国家

SELECT cc, cn
FROM ip
NATURAL JOIN cc
WHERE INET_ATON(  "157.191.122.36" ) 
BETWEEN START AND END

这将为我提供以下输出结果：

cc | cn
--------
US | United States

这是正确的，因为它根据提供的IP地址给出了正确的国家。

借助上述展示的三个表格和两个查询的帮助，我需要展示以下结果:

Country Visited | No. of Times
_______________________________
United States   |   482
Korea           |   213
Pakistan        |   123

....

附录（表格的结构和数据）

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（结构）

CREATE TABLE IF NOT EXISTS `mslop_login_activity` (
  `aid` int(10) unsigned NOT NULL AUTO_INCREMENT COMMENT 'The primary identifier for an activity (session).',
  `uid` int(10) unsigned NOT NULL DEFAULT '0' COMMENT 'The mslop_users.uid corresponding to a session, or 0 for anonymous user.',
  `host_user_agent` varchar(256) NOT NULL DEFAULT '' COMMENT '$_SERVER["HOST_USER_AGENT"] string. This can be used with get_browser() in PHP.',
  `hostname` varchar(128) NOT NULL DEFAULT '' COMMENT 'The IP address that was used for this session.',
  `timestamp` int(11) NOT NULL DEFAULT '0' COMMENT 'The UNIX timestamp when the session was started.',
  PRIMARY KEY (`aid`),
  KEY `aid` (`aid`),
  KEY `uid` (`uid`),
  KEY `timestamp` (`timestamp`)
);

（数据）

INSERT INTO `mslop_login_activity` (`aid`, `uid`, `host_user_agent`, `hostname`, `timestamp`) VALUES
(1, 3, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:19.0) Gecko/20100101 Firefox/19.0', '172.24.1.143', 1363038356),
(873, 4, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/534.59.8 (KHTML, like Gecko) Version/5.1.9 Safari/534.59.8', '157.191.122.36', 1369773601),
(883, 83, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; Tablet PC 2.0)', '157.191.122.36', 1369774959),
(893, 83, 'Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.64 Safari/537.31', '157.191.122.36', 1369818602),
(903, 83, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; GTB7.4; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; Tablet PC 2.0)', '157.191.122.36', 1369838690),
(913, 83, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; GTB7.4; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; Tablet PC 2.0; AskTbORJ/5.15.23.36191)', '157.191.122.36', 1369840224),
(923, 83, 'Mozilla/5.0 (Windows NT 6.1; rv:21.0) Gecko/20100101 Firefox/21.0', '157.191.122.36', 1369841748),
(933, 83, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; Tablet PC 2.0)', '157.191.122.36', 1370255417),
(943, 83, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E)', '157.191.122.36', 1370258059),
(953, 83, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E)', '157.191.122.36', 1370258060),
(963, 93, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; AskTbORJ/5.15.15.36191)', '157.191.122.36', 1370299827),
(973, 93, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; AskTbORJ/5.15.15.36191)', '157.191.122.36', 1370299852),
(983, 93, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/534.59.8 (KHTML, like Gecko) Version/5.1.9 Safari/534.59.8', '157.191.122.36', 1370299899),
(993, 93, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/534.59.8 (KHTML, like Gecko) Version/5.1.9 Safari/534.59.8', '157.191.122.36', 1370299920),
(1003, 93, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/534.59.8 (KHTML, like Gecko) Version/5.1.9 Safari/534.59.8', '157.191.122.36', 1370299995),
(1013, 93, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.93 Safari/537.36', '157.191.122.36', 1370319811),
(1023, 3, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.93 Safari/537.36', '157.191.122.36', 1370319835),
(1033, 93, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.93 Safari/537.36', '157.191.122.36', 1370319939),
(1043, 83, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.93 Safari/537.36', '157.191.122.36', 1370320312),
(1053, 93, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.93 Safari/537.36', '157.191.122.36', 1370320640),
(1063, 3, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.93 Safari/537.36', '157.191.122.36', 1370320713),
(1073, 83, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.93 Safari/537.36', '157.191.122.36', 1370363702),
(1083, 83, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.93 Safari/537.36', '157.191.122.36', 1370363987),
(1093, 3, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.93 Safari/537.36', '157.191.122.36', 1370364021),
(1103, 3, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.93 Safari/537.36', '157.191.122.36', 1370364028),
(1113, 83, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.93 Safari/537.36', '157.191.122.36', 1370365896),
(1123, 93, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.93 Safari/537.36', '157.191.122.36', 1370366087),
(1133, 93, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/534.59.8 (KHTML, like Gecko) Version/5.1.9 Safari/534.59.8', '157.191.122.36', 1370367070),
(1143, 3, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.93 Safari/537.36', '157.191.122.36', 1370368567),
(1153, 3, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.93 Safari/537.36', '157.191.122.36', 1370368575),
(1163, 83, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; Tablet PC 2.0)', '157.191.122.36', 1370379345),
(1173, 83, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; GTB7.4; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; Tablet PC 2.0)', '157.191.122.36', 1370427302),
(1183, 83, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; .NET CLR 1.1.4322)', '157.191.122.36', 1370503422),
(1193, 93, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/534.59.8 (KHTML, like Gecko) Version/5.1.9 Safari/534.59.8', '157.191.122.36', 1370534329),
(1203, 83, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; Tablet PC 2.0)', '157.191.122.36', 1370866207),
(1213, 83, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; .NET CLR 1.1.4322)', '157.191.122.36', 1370871353),
(1223, 83, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; chromeframe/26.0.1410.43; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; Tablet PC 2.0)', '157.191.122.36', 1370877702),
(1233, 83, 'Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.110 Safari/537.36', '157.191.122.36', 1371015245),
(1243, 83, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; Tablet PC 2.0)', '157.191.122.36', 1371069245),
(1253, 83, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E)', '157.191.122.36', 1371117509),
(1263, 83, 'Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.110 Safari/537.36', '157.191.122.36', 1371137716),
(1273, 83, 'Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)', '157.191.122.36', 1371197327),
(1283, 83, 'Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.110 Safari/537.36', '157.191.122.36', 1371427531),
(1293, 83, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E)', '157.191.122.36', 1371552899),
(1303, 83, 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E)', '157.191.122.36', 1371635304),
(1313, 93, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/534.59.8 (KHTML, like Gecko) Version/5.1.9 Safari/534.59.8', '157.191.122.36', 1371770752),
(1323, 93, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/534.59.8 (KHTML, like Gecko) Version/5.1.9 Safari/534.59.8', '157.191.122.36', 1371771394),
(1333, 3, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.110 Safari/537.36', '157.191.122.36', 1371771647),
(1343, 3, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/536.26.17 (KHTML, like Gecko) Version/6.0.2 Safari/536.26.17', '157.191.122.36', 1371772611),
(1353, 3, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/536.26.17 (KHTML, like Gecko) Version/6.0.2 Safari/536.26.17', '157.191.122.36', 1371772626),
(1363, 3, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.110 Safari/537.36', '157.191.122.36', 1371772931),
(1373, 93, 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SIMBAR={37EF0ACB-CCB3-11E2-9611-E006E6BAE768}; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET4.0C; .NET4.0E; AskTbORJ/5.15.15.36191)', '157.191.122.36', 1371782438),
(1383, 93, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_6_8) AppleWebKit/534.59.8 (KHTML, like Gecko) Version/5.1.9 Safari/534.59.8', '157.191.122.36', 1371782562),
(1393, 3, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.116 Safari/537.36', '157.191.122.36', 1371790767),
(1403, 83, 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/536.26.17 (KHTML, like Gecko) Version/6.0.2 Safari/536.26.17', '157.191.122.36', 1371834780);

cc

(Structure)

CREATE TABLE cc (
        ci TINYINT UNSIGNED NOT NULL PRIMARY KEY AUTO_INCREMENT,
        cc CHAR(2) NOT NULL,
        cn VARCHAR(50) NOT NULL
        );

(数据)

由于文件较大，您可以通过以下链接下载：

http://d.pr/f/N3KT

IP地址

(结构)

CREATE TABLE ip (
        start INT UNSIGNED NOT NULL,
        end INT UNSIGNED NOT NULL,
        ci TINYINT UNSIGNED NOT NULL
        );

(数据)

由于它很大，您可以通过此链接下载：-

http://d.pr/f/wcEy.

- Steve

2

你在第一条语句中使用的 group by 是无效的，但 MySQL 不会像其他 DBMS 一样拒绝它 - 它只是选择返回随机数据。阅读这篇文章以了解原因：http://rpbouman.blogspot.de/2007/05/debunking-group-by-myths.html 和 http://www.mysqlperformanceblog.com/2006/09/06/wrong-group-by-makes-your-queries-fragile/ - user330315

你是在寻找独特的访问量还是独特的访客？ - Gordon Linoff

嗨，Gordon，我正在寻找Unique Visits和horse_with_no_name，关于Group By，我想使用其他东西，如果它能够工作，但是由于我的知识有限，我似乎选择较少。 - Steve

1个回答

网页内容由stack overflow 提供, 点击上面的

可以查看英文原文，
原文链接

- jazzytomato · Accepted Answer

1

尝试以下查询：

SELECT cn As 'Country Visited', count(0) AS 'No. of Times'
FROM mslop_login_activity a
INNER JOIN ip ON ( INET_ATON(a.hostname) BETWEEN START AND END )
NATURAL JOIN CC
GROUP BY cn

- jazzytomato

嗨，Thomas，我尝试使用IP地址157.191.122.36运行脚本，而不是INET_ATON（a.hostname）（因为这个IP地址在login_activity表中最常见），查询结果显示美国|208。然后我在login_activity表中添加了荷兰的样本IP（5.10.88.12）作为测试，正确的响应应该是荷兰|3，但它给了我荷兰|280。所以无论我输入什么IP地址，数字280都会出现。如果您能帮忙解决问题，我将非常感激...谢谢。 - Steve

我一直在尝试修复这个问题，但是无法让它正常工作...如果您能帮助我解决这个问题，我将非常感激... - Steve

@Steve 如果您从连接条件中删除 a，则将返回来自 a 的所有行，因为它们不再与 ip 相关联。如果您只想测试一个 IP，请使用 where a.hostname = '157.191.122.36'。 - Nikola Markovinović

嗨，尼古拉，我尝试了你提到的方法，但没有成功。可能是我做错了。你介意在更改后写下具体的查询吗？非常感谢。 - Steve

各位有任何帮助，我将不胜感激。 - Steve

我的查询 + 自然连接 CC 其中 a.hostname = '157.191.122.36' 按 cn 分组 - jazzytomato