{"id":4264,"date":"2020-04-10T20:14:01","date_gmt":"2020-04-10T12:14:01","guid":{"rendered":"https:\/\/damogame.cn\/wordpress\/?p=4264"},"modified":"2020-04-10T20:14:01","modified_gmt":"2020-04-10T12:14:01","slug":"mysql-btree%e5%92%8chash%e7%b4%a2%e5%bc%95%e7%9a%84%e6%af%94%e8%be%83%ef%bc%8c%e4%b8%ba%e4%bb%80%e4%b9%88innodb%e4%b8%8d%e4%bd%bf%e7%94%a8hash%e7%b4%a2%e5%bc%95","status":"publish","type":"post","link":"https:\/\/i007.cc\/wordpress\/archives\/4264","title":{"rendered":"MySql BTree\u548cHash\u7d22\u5f15\u7684\u6bd4\u8f83\uff0c\u4e3a\u4ec0\u4e48InnoDB\u4e0d\u4f7f\u7528Hash\u7d22\u5f15"},"content":{"rendered":"

\u539f\u6587\u5730\u5740<\/a><\/p>\n

 <\/p>\n

\u539f\u521b\u5e0c\u5c24 \u6700\u540e\u53d1\u5e03\u4e8e2019-01-15 17:17:32 \u9605\u8bfb\u6570 1044 \u6536\u85cf
\n\u5c55\u5f00
\nMYSQL \u7d22\u5f15\u5206\u6790<\/p>\n

\u5173\u4e8eBtree\u80fd\u5b58\u50a8\u591a\u5c11\u6570\u636e\u7684\u5206\u6790<\/p>\n

-1 \u4e3a\u5565\u8981\u7528B+Tree\u800c\u4e0d\u7528btree?
\nbtree\u6240\u6709\u7684\u8282\u70b9\u90fd\u5b58\u50a8\u6570\u636e\uff0c\u800cb+tree\u53ea\u6709\u53f6\u5b50\u8282\u70b9\u624d\u5b58\u50a8\u6570\u636e
\n\u800c\u5185\u5b58\u6bcf\u6b21\u52a0\u8f7d\u6570\u636e\u7684\u5927\u5c0f\u662f\u6709\u9650\u7684\uff0c\u800c\u6709\u6570\u636e\u7684\u65f6\u5019\uff0c\u52a0\u8f7d\u7684\u91cf\u5c31\u4f1a\u5f88\u5c0f\uff0c\u5982\u679c\u90fd\u662f\u7d22\u5f15\uff0c\u5c31\u4f1a\u52a0\u8f7d\u66f4\u591a\u7684\u7d22\u5f15\u503c<\/p>\n

0. B+Tree\u80fd\u5b58\u591a\u5c11\u6570\u636e
\nmysql> show global status like ‘Innodb_page_size’;
\n+——————+——-+
\n| Variable_name | Value |
\n+——————+——-+
\n| Innodb_page_size | 16384 |
\n+——————+——-+
\n1 row in set
\n1
\n2
\n3
\n4
\n5
\n6
\n7
\ninnodb\u7684\u6240\u6709\u6570\u636e\u6587\u4ef6.idb\u5927\u5c0f\u90fd\u662f16K\u537316384\u7684\u6574\u6570\u500d
\n\u6211\u4eec\u7684InnoDB\u9875\u7684\u5927\u5c0f\u9ed8\u8ba4\u662f16k\uff1f\u4e3a\u5565\u662f16K\uff1f\u56e0\u4e3a16K\u7684\u8bdd\uff0c\u9ad8\u5ea6\u4e3a3\u7684\u6811\u5c31\u53ef\u4ee5\u5b58\u50a8\u5343\u4e07\u7ea7\u522b\u7684\u6570\u636e\uff0c\u5982\u4e0b\u6709\u8bf4\u660e
\n\u5047\u8bbe\u4e00\u884c\u6570\u636e\u7684\u5927\u5c0f\u662f1k\uff0c\u90a3\u4e48\u4e00\u4e2a\u9875\u53ef\u4ee5\u5b58\u653e16\u884c\u8fd9\u6837\u7684\u6570\u636e\u3002
\n\u6211\u4eec\u5047\u8bbe\u4e3b\u952eID\u4e3abigint\u7c7b\u578b\uff0c\u957f\u5ea6\u4e3a8\u5b57\u8282\uff0c\u800c\u6307\u9488\u5927\u5c0f\u5728InnoDB\u6e90\u7801\u4e2d\u8bbe\u7f6e\u4e3a6\u5b57\u8282\uff0c\u8fd9\u6837\u4e00\u517114\u5b57\u8282
\n\u6211\u4eec\u4e00\u4e2a\u9875\u4e2d\u80fd\u5b58\u653e\u591a\u5c11\u8fd9\u6837\u7684\u5355\u5143\uff0c\u5176\u5b9e\u5c31\u4ee3\u8868\u6709\u591a\u5c11\u6307\u9488\uff0c\u537316384\/14=1170\u3002
\n\u90a3\u4e48\u53ef\u4ee5\u7b97\u51fa\u4e00\u68f5\u9ad8\u5ea6\u4e3a2\u7684B+\u6811\uff0c\u5373\u5b58\u5728\u4e00\u4e2a\u6839\u8282\u70b9\u548c\u82e5\u5e72\u4e2a\u53f6\u5b50\u8282\u70b9\uff0c\u90a3\u4e48\u8fd9\u68f5B+\u6811\u7684\u5b58\u653e\u603b\u8bb0\u5f55\u6570\u4e3a\uff1a\u6839\u8282\u70b9\u6307\u9488\u6570\u5355\u4e2a\u53f6\u5b50\u8282\u70b9\u8bb0\u5f55\u884c\u6570\u3002\u80fd\u5b58\u653e117016=18720\u6761\u8fd9\u6837\u7684\u6570\u636e\u8bb0\u5f55\u3002
\n\u6839\u636e\u540c\u6837\u7684\u539f\u7406\u6211\u4eec\u53ef\u4ee5\u7b97\u51fa\u4e00\u4e2a\u9ad8\u5ea6\u4e3a3\u7684B+\u6811\u53ef\u4ee5\u5b58\u653e\uff1a1170117016=21902400\u6761\u8fd9\u6837\u7684\u8bb0\u5f55\u3002
\n\u6240\u4ee5\u5728InnoDB\u4e2dB+\u6811\u9ad8\u5ea6\u4e00\u822c\u4e3a1-3\u5c42\uff0c\u5b83\u5c31\u80fd\u6ee1\u8db3\u5343\u4e07\u7ea7\u7684\u6570\u636e\u5b58\u50a8\u3002
\n\u5728\u67e5\u627e\u6570\u636e\u65f6\u4e00\u6b21\u9875\u7684\u67e5\u627e\u4ee3\u8868\u4e00\u6b21IO\uff0c\u6240\u4ee5\u901a\u8fc7\u4e3b\u952e\u7d22\u5f15\u67e5\u8be2\u901a\u5e38\u53ea\u9700\u89811-3\u6b21IO\u64cd\u4f5c\u5373\u53ef\u67e5\u627e\u5230\u6570\u636e\u3002<\/p>\n

1.B+Tree
\n\u4e4b\u6240\u4ee5Btree\u80fd\u52a0\u5feb\u8bbf\u95ee\u6570\u636e\u7684\u901f\u5ea6\uff0c\u662f\u56e0\u4e3a\u5b58\u50a8\u5f15\u64ce\u4e0d\u518d\u9700\u8981\u8fdb\u884c\u5168\u8868\u626b\u63cf
\n\u53ea\u9700\u8981\u4ece\u7d22\u5f15\u7684\u6839\u8282\u70b9\u5f00\u59cb\u8fdb\u884c\u641c\u7d22\uff0c\u6839\u8282\u70b9\u7684\u69fd\u4e2d\u5b58\u653e\u4e86\u6307\u5411\u5b50\u8282\u70b9\u7684\u6307\u9488\uff0c
\n\u5b58\u50a8\u5f15\u64ce\u4f1a\u6839\u636e\u8fd9\u4e9b\u6307\u9488\u5411\u4e0b\u5c42\u67e5\u627e\uff0c\u800c\u8fd9\u4e9b\u6307\u9488\u5b9e\u9645\u4e0a\u5b9a\u4e49\u4e86\u5b50\u8282\u70b9\u9875\u4e2d\u503c\u7684\u4e0a\u9650\u548c\u4e0b\u7ebf
\n1
\n2
\n3
\n\u6bd4\u5982\uff1a<\/p>\n

create table people(
\nxing varchar(20) not null,
\nming varchar(20) not null,
\nbirthday date not null,
\ngender enum(‘male’,’unknow’,’female’) not null,
\nkey(last_name ,first_name,birthday)
\n)
\n1
\n2
\n3
\n4
\n5
\n6
\n7
\n\u7d22\u5f15\u5982\u679c\u67e5\u8be2\u591a\u6761\u6570\u636e\uff0c\u4e5f\u662f\u53ef\u4ee5\u6392\u5e8f\u7684<\/p>\n

2. BTREE\u7d22\u5f15\u4f7f\u7528\u7684\u9650\u5236
\n1. \u5982\u679c\u4e0d\u662f\u6309\u7167\u6700\u5de6\u5217\u5f00\u59cb\u67e5\u627e\uff0c\u65e0\u6cd5\u4f7f\u7528\u7d22\u5f15
\n\u4f8b\u5982\u65e0\u6cd5\u7528\u4e8e\u67e5\u627e ming\u4e3aXXX\u7684\uff0c\u4e5f\u65e0\u6cd5\u67e5\u627e birthday\u4e3aXXX\u7684
\nABC\u4e09\u4e2a\u7ec4\u6210\u7684\u7d22\u5f15\uff0c\u53ea\u80fdA \u3001AB\u3001 ABC
\n\u5176\u5b83\u7684\u7ec4\u5408\u90fd\u662f\u65e0\u6cd5\u7528\u5230\u7d22\u5f15\u7684
\n1
\n2
\n3
\n4
\n2. \u5982\u679c\u4e2d\u95f4\u6709\u4e00\u5217\u662f\u8303\u56f4\u67e5\u8be2\uff0c\u5219\u4e4b\u540e\u7684\u5217\u4e0d\u80fd\u7528\u4e8e\u7d22\u5f15\u67e5\u8be2
\n\u6bd4\u5982
\nWHERE A =XXX AND B like ‘XXX%’ and C =XXX
\n\u8fd9\u4e2a\u7d22\u5f15\u53ea\u80fd\u7528\u5230\u524d\u4e24\u5217
\n1
\n2
\n3
\n4
\nHASH\u7d22\u5f15
\n\u5728InnoDB\u4e0a\u9762\u521b\u5efaHASH\u7d22\u5f15<\/p>\n

1
\n\u6211\u4eec\u5229\u7528<\/p>\n

\u5148\u67e5\u8be2\u5f53\u524d\u6570\u636e\u5e93\u7684\u7248\u672c
\nmysql> select version();
\n\u67e5\u8be2\u5f53\u524d\u5b9e\u9645\u8868\u7ed3\u6784
\nshow create table peopleHash ;<\/p>\n

1
\n2
\n3
\n4
\n5
\n6
\nmysql> show create table peopleHash ;<\/p>\n

| peopleHash | CREATE TABLE `peoplehash` (
\n`xing` varchar(20) COLLATE utf8mb4_general_ci NOT NULL,
\n`ming` varchar(20) COLLATE utf8mb4_general_ci NOT NULL,
\n`birthday` date NOT NULL,
\n`gender` enum(‘male’,’unknow’,’female’) COLLATE utf8mb4_general_ci NOT NULL,
\nKEY `ming` (`ming`)
\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci |
\n1
\n2
\n3
\n4
\n5
\n6
\n7
\n8
\n9
\n2. 1 \u4e3a\u4ec0\u4e48\u5728InnoDB\u521b\u5efaHASH\u7d22\u5f15\u5931\u8d25\uff1f
\n\u7ed3\u679c\u5e76\u6ca1\u6709\u51fa\u73b0\u6211\u4eec\u60f3\u8981\u7684USING HASH \uff0c\u4e5f\u5c31\u662f\u8bf4\u521b\u5efaHASH\u7d22\u5f15\u5931\u8d25
\n\u4e3a\u4ec0\u4e48\u5462\uff1f<\/p>\n

1
\n2
\n3
\n\u4e0b\u9762\u662fMYSQL\u5b98\u65b9\u7684\u56de\u7b54\uff1a
\n1.\u4e0d\u652f\u6301HASH\u7d22\u5f15\uff08\u4f46\u662fInnoDB\u5728\u5185\u90e8\u5229\u7528\u54c8\u5e0c\u7d22\u5f15\u6765\u5b9e\u73b0\u5176\u81ea\u9002\u5e94\u54c8\u5e0c\u7d22\u5f15\u529f\u80fd\u3002\uff09<\/p>\n

2.\u4e5f\u5c31\u662fInnoDB\u4f1a\u6839\u636e\u8868\u7684\u4f7f\u7528\u60c5\u51b5\u81ea\u52a8\u4e3a\u8868\u751f\u6210hash\u7d22\u5f15\uff0c\u4e0d\u80fd\u4eba\u4e3a\u5e72\u9884\u662f\u5426\u5728InnoDB\u4e00\u5f20\u8868\u4e2d\u521b\u5efaHASH\u7d22\u5f15<\/p>\n

3.\u6216\u8005\u8bf4\uff0c\u5982\u679cInnoDB\u6ce8\u610f\u5230\u67d0\u4e9b\u7d22\u5f15\u503c\u88ab\u4f7f\u7528\u7684\u7279\u522b\u9891\u7e41\u65f6\uff0c
\n\u5b83\u4f1a\u5728\u5185\u5b58\u4e2d\u57fa\u4e8eBtree\u7684\u7d22\u5f15\u4e4b\u4e0a\u518d\u521b\u5efa\u4e00\u4e2aHASH\u7d22\u5f15\uff0c\u8fd9\u6837BTREE\u7d22\u5f15\u4e5f\u5177\u5907\u4e86HASH\u7d22\u5f15\u7684\u4e00\u4e9b\u4f18\u70b9
\n1
\n2
\n3
\n4
\n5
\n6
\n7
\n\u4f46\u662f\u4e5f\u6ca1\u6709\u652f\u6301HSAH\u7d22\u5f15\u7684\u5f15\u64ce\u5462\uff1f<\/p>\n

\u7b54\u6848\u662f\u80af\u5b9a\u7684\uff1a
\nMEMORY\u5f15\u64ce\u662f\u652f\u6301\u7684
\n1
\n2
\n2.2 \u4e3a\u4ec0\u4e48InnoDB\u548cMyISAM\u5f15\u64ce\u4e0d\u652f\u6301HASH\u7d22\u5f15\uff1f
\n1. HASH\u7d22\u5f15\u672c\u8eab\u53ea\u5b58\u50a8\u5bf9\u5e94\u7684HASH\u503c\u548c\u884c\u6307\u9488\uff0c\u800c\u4e0d\u662f\u5b58\u50a8\u5b57\u6bb5\u503c
\n2. HASH\u7d22\u5f15\u5e76\u4e0d\u662f\u6309\u7167\u7d22\u5f15\u987a\u5e8f\u6765\u5b58\u50a8\u7684\uff0c\u56e0\u6b64\u65e0\u6cd5\u6392\u5e8f
\n3. HASH\u7d22\u5f15\u4e0d\u652f\u6301\u90e8\u5206\u7d22\u5f15\u5217\u67e5\u627e\uff0c\u56e0\u4e3aHASH\u7d22\u5f15\u662f\u4f7f\u7528\u5168\u90e8\u7684\u5185\u5bb9\u6765\u8ba1\u7b97HASH\u503c\u7684
\n\u4f8b\u5982\u5728\uff08A,B\uff09\u4e24\u5217\u5efa\u7acb\u7d22\u5f15\uff0c\u53ea\u67e5\u8be2A\u65e0\u6cd5\u4f7f\u7528\u7d22\u5f15
\n4.HASH\u7d22\u5f15\u53ea\u652f\u6301\u7b49\u503c\u6bd4\u8f83\u67e5\u8be2\uff0c\u5305\u62ec =\u3001IN\uff08\uff09\u4e0d\u80fd\u8fdb\u884c\u4efb\u4f55\u7684\u8303\u56f4\u67e5\u8be2<\/p>\n

1
\n2
\n3
\n4
\n5
\n6
\nHASH\u51b2\u7a81
\n5. \u6700\u4e25\u91cd\u7684\u662f\u65e2\u7136HASH\u503c\u662f\u6570\u5b57\uff0c\u80af\u5b9a\u4f1a\u51fa\u73b0\u76f8\u540c\u7684\uff0c\u4e5f\u5c31\u662fHASH\u51b2\u7a81
\n1
\n6. \u51fa\u73b0HASH\u51b2\u7a81\u7684\u65f6\u5019\uff0c\u5b58\u50a8\u5f15\u64ce\u5fc5\u987b\u904d\u5386\u94fe\u8868\u4e2d\u6240\u6709\u7684\u884c\u6307\u9488\uff0c\u9010\u884c\u8fdb\u884c\u6bd4\u8f83\uff0c\u76f4\u5230\u627e\u5230\u6240\u6709\u7b26\u5408\u6761\u4ef6\u7684\u884c
\n1
\n7. \u5f53HASH\u51b2\u7a81\u7279\u522b\u591a\u7684\u65f6\u5019\uff0c\u7ef4\u62a4\u64cd\u4f5c\u7684\u6210\u672c\u5c31\u4f1a\u53d8\u5927\uff0c\u6bd4\u5982\u4e00\u6b21\u6570\u636e\u7684\u5220\u9664
\n\u5f15\u64ce\u9700\u8981\u904d\u5386\u5bf9\u5e94HASH\u503c\u94fe\u8868\u4e0a\u7684\u6bcf\u4e00\u884c\uff0c\u627e\u5230\u5e76\u5220\u9664\u5bf9\u5e94\u7684\u5f15\u7528\uff0c\u51b2\u7a81\u8d8a\u591a\uff0c\u4ee3\u4ef7\u8d8a\u5927
\n1
\n2
\n3. \u6a21\u62df\u4e00\u4e2aHASH\u7d22\u5f15
\n\u6bd4\u5982\u53ea\u6709\u4e24\u4e2a\u5b57\u6bb5 ID \u548cURL
\n\u6211\u4eec\u60f3\u67e5\u8be2URL\u662f\u4ec0\u4e48\u7684 select id from XXX where url =’http:\/\/XXXXXXXX’
\n1
\n2
\n\u5982\u679c\u7528BTREE\u6765\u5b58\u50a8URL\uff0c\u5219\u9700\u8981\u7528\u5230\u5927\u91cf\u7684\u7a7a\u95f4\uff0c\u90a3\u6211\u4eec\u8fd8\u60f3\u7528\u7d22\u5f15\uff0c\u600e\u4e48\u529e\u5462\uff1f
\n1
\n\u5220\u9664URL\u539f\u6765\u7684\u7d22\u5f15\uff0c\u65b0\u589e\u4e00\u4e2a\u5b57\u6bb5 url_crc \u4f7f\u7528CRC32\u505aHASH
\nselect id from XXX where url =’http:\/\/XXXXXXXX’ and url_crc =CRC32(‘http:\/\/XXXXXXXX’)
\n1
\n2
\n1.\u53ea\u8981\u5728\u63d2\u5165\u548c\u66f4\u65b0\u6570\u636e\u7684\u65f6\u5019\uff0c\u5bf9url_crc\u8fdb\u884c\u66f4\u65b0\u5c31\u53ef\u4ee5\u4e86
\n2. \u4f46\u662f\u5982\u679c\u7528\u8fd9\u4e2a\u65b9\u5f0f\uff0c\u8bb0\u4f4f\u4e0d\u8981\u7528SHA1() MD5()\u4f5c\u4e3aHASH\u51fd\u6570
\n3. \u56e0\u4e3a\u90a3\u4e24\u4e2a\u51fd\u6570\u7684hash\u503c\u975e\u5e38\u957f\uff0c\u4f1a\u6d6a\u8d39\u5927\u91cf\u7684\u7a7a\u95f4\uff0c\u4f46\u662f\u5982\u679c\u6570\u636e\u91cf\u975e\u5e38\u5927\uff0cCRC32()\u4f1a\u51fa\u73b0\u5927\u91cf\u51b2\u7a81
\n1
\n2
\n3
\n4. \u81ea\u5b9a\u4e4964\u4f4d\u7684\u54c8\u5e0c\u51fd\u6570
\n\u7b80\u5355\u7684\u505a\u6cd5\u662f\uff1a\u7528MD5()\u51fd\u6570\u8fd4\u56de\u503c\u7684\u4e00\u90e8\u5206\u4f5c\u4e3a\u81ea\u5b9a\u4e49\u54c8\u5e0c\u51fd\u6570
\nselect CONV(RIGHT(MD5(‘http:\/\/XXXXXXX’),16),16,10)AS HASH64;
\n\u63d2\u5165\u548c\u66f4\u65b0\u7684\u65f6\u5019\u90fd\u53ef\u4ee5\u7528\u8fd9\u4e2a\u4e86
\ninsert into XXX
\n(id,url,url_crc) values
\n(XXX,XXX ,CONV(RIGHT(MD5(‘http:\/\/XXXXXXX’),16),16,10));
\n1
\n2
\n3
\n4
\n5
\n6
\n7
\n4. \u7d22\u5f15\u662f\u6700\u597d\u7684\u89e3\u51b3\u65b9\u6848\u5417
\n\u5f53\u7136\u4e0d\u662f
\n1.\u5bf9\u4e8e\u6570\u636e\u91cf\u7279\u522b\u5c0f\u7684\u8868\uff0c\u5168\u8868\u626b\u63cf\u66f4\u9ad8\u6548\uff0c\u6ca1\u5fc5\u8981\u7d22\u5f15
\n2.\u4e2d\u5230\u5927\u578b\u7684\u8868\uff0c\u7d22\u5f15\u5f88\u9ad8\u6548\uff0c\u6ca1\u6709\u7684\u8bdd\uff0c\u901f\u5ea6\u5f88\u4f4e
\n3.\u8d85\u5927\u578b\u8868\uff0c\u7531\u4e8e\u6570\u636e\u91cf\u5927\uff0c\u7d22\u5f15\u4f7f\u7528\u7684\u4ee3\u4ef7\u4f1a\u5f88\u5927\uff0c\u8fd9\u79cd\u60c5\u51b5\u4e0b\u53ef\u4ee5\u4f7f\u7528
\n\u5206\u533a\u6280\u672f
\n1
\n2
\n3
\n4
\n5
\n5. \u7d22\u5f15\u7684\u5206\u7c7b
\nMYISAM\u5f15\u64ce\uff0c\u975e\u805a\u96c6\u7d22\u5f15
\n\u56e0\u4e3a\u7d22\u5f15\u6587\u4ef6myi\u548c\u6570\u636e\u6587\u4ef6myd\u662f\u5206\u5f00\u7684\uff0cmyi\u91cc\u9762\u5b58\u50a8\u7684\u662fmyd\u6587\u4ef6\u7684\u6307\u9488,\u800c\u4e14\u4e3b\u952e\u7d22\u5f15\u548c\u975e\u4e3b\u952e\u7d22\u5f15\u6ca1\u6709\u5c42\u6b21\u5173\u7cfb\uff0c\u56e0\u4e3a\u5b58\u50a8\u7684\u90fd\u662f\u6307\u5411myd\u6587\u4ef6\u7684\u6307\u9488
\nInnodb\u5f15\u64ce\u662f\u805a\u96c6\u7d22\u5f15
\n\u53ea\u6709\u4e00\u4e2aidb\u6587\u4ef6\uff0c\u5728\u4e3b\u952e\u7d22\u5f15\u548c\u975e\u4e3b\u952e\u7d22\u5f15\u6709\u5c42\u6b21\u7684\u5173\u7cfb\uff0c\u56e0\u4e3a\u4e3b\u952e\u7d22\u5f15\u5b58\u50a8\u7684\u662f\u771f\u662f\u7684\u4fe1\u606f\uff0c\u800c\u975e\u4e3b\u952e\u7d22\u5f15\u5b58\u50a8\u7684\u662f\u4e3b\u952e\u7684\u4fe1\u606f
\n6. \u521b\u5efa\u7d22\u5f15\u7684\u539f\u5219
\n\u5217\u7684\u79bb\u6563\u578b\uff1a
\n\u79bb\u6563\u578b\u7684\u8ba1\u7b97\u516c\u5f0f\uff1acount(distinct col):count(col)\uff0c\u79bb\u6563\u578b\u8d8a\u9ad8\uff0c\u9009\u62e9\u578b\u8d8a\u597d\u3002
\n\u6bd4\u5982\u6027\u522b\u5b57\u6bb5\uff0c\u53ea\u6709\u7537\u5973\u3001\u672a\u77e5\u7b49\u5728\u7d22\u5f15\u67e5\u8be2\u7684\u65f6\u5019\u5176\u5b9e\u8fd8\u4e0d\u5982\u5168\u8868\u626b\u63cf\uff0c\u56e0\u4e3a\u5728\u7d22\u5f15\u521b\u5efa\u7684\u65f6\u5019\uff0c\u5982\u679c\u6b64\u65f6\u68c0\u7d22 sex = 1\u7684\u6570\u636e\uff0c\u6839\u8282\u70b9\u5224\u65ad\u7684\u65f6\u5019\uff0c\u7ed3\u679c\u662f\u67e5\u8be2\u5de6\u5b50\u6811\uff0c\u4f46\u662f\u5f53\u5728\u5de6\u5b50\u6811\u7b2c\u4e8c\u5c42\u518d\u8fdb\u884c\u5224\u65ad\u7684\u65f6\u5019\uff0c\u56e0\u4e3a\u5de6\u53f3\u5206\u652f\u90fd\u6ee1\u8db3\u6761\u4ef6\uff0c\u6240\u4ee5\u5f88\u96be\u6289\u62e9\u9009\u62e9\u54ea\u4e00\u4e2a\u5206\u652f\u7ee7\u7eed\u641c\u7d22\uff0c\u6216\u8005\u662f\u628a\u4e24\u4e2a\u5206\u652f\u540c\u65f6\u8fdb\u884c\u641c\u7d22\u3002\u5982\u56fe\uff1a<\/p>\n

\u6700\u5de6\u5339\u914d\u539f\u5219\u5e76\u4e14\u4f18\u5148\u521b\u5efa\u8054\u5408\u7d22\u5f15\u539f\u5219
\n\u8fd9\u4e2a\u5f88\u591a\u4ecb\u7ecd\uff0c\u4e0d\u5fc5\u8bf4\u4e86
\n\u8986\u76d6\u7d22\u5f15\uff1a
\n\u5047\u5982teacherNo \u4f7f\u7528\u5230\u4e86\u7d22\u5f15\uff0c\u68c0\u7d22\u5230teacherNo \u65f6\u5019\uff0c\u53ef\u4ee5\u76f4\u63a5\u5c06\u7d22\u5f15\u4e2d\u7684teacherNo \u503c\u8fd4\u56de\uff0c\u4e0d\u9700\u8981\u8fdb\u5165\u6570\u636e\u533a\u3002
\nSelect teacherNo from teacher where teacherNo = ?
\n1
\n7. mysql\u4e3a\u5565\u4e0d\u63a8\u8350\u7528UUID
\nUUID\u5b57\u6bb5\u5f88\u957f\uff0c\u800c\u4e14\u4e0d\u662fint\u7c7b\u578b\u7684\uff0c\u5b58\u50a8\u7684\u6570\u636e\u91cf\u5c31\u4f1a\u5927\u5927\u51cf\u5c11\uff0c\u7d22\u5f15\u6548\u7387\u4e0d\u9ad8
\nUUID\u56e0\u4e3a\u4e0d\u662f\u81ea\u589e\u7684\uff0c\u5728\u63d2\u5165\u7d22\u5f15\u7684\u65f6\u5019\uff0c\u4f1a\u5bf9\u539f\u6709\u7684\u53f6\u7247\u5c31\u884c\u7ef4\u62a4\u5e76\u5206\u88c2\u7684\u6210\u672c\u7279\u522b\u9ad8
\n\u6bd4\u5982\u662f\u81ea\u589e\u7684iD\uff0c\u6211\u4eec\u770b\u4e0b\u662f\u600e\u4e48\u8fdb\u884c\u5206\u88c2\u7684,\u5728\u4e0b\u56fe\u4e2d\u63d2\u51657\uff0c\u5e76\u4e14\u89c4\u5b9a\u4e00\u4e2a\u4e00\u7247\u4e2d\u53ea\u80fd\u63d2\u51654\u4e2a\u8bb0\u5f55<\/p>\n

\u63d2\u5165\u8bb0\u5f557\uff0c\u7531\u4e8e\u53f6\u9875\u9762\u4e2d\u53ea\u80fd\u5b58\u653e4\u6761\u8bb0\u5f55\uff0c\u63d2\u5165\u8bb0\u5f557\uff0c\u5bfc\u81f4\u53f6\u9875\u9762\u5206\u88c2\uff0c\u4ea7\u751f\u4e00\u4e2a\u65b0\u7684\u53f6\u9875\u9762\u3002<\/p>\n

\u4f20\u7edfB+\u6811\u9875\u9762\u5206\u88c2\u64cd\u4f5c\u5206\u6790\uff1a
\n\u6309\u7167\u539f\u9875\u9762\u4e2d50%\u7684\u6570\u636e\u91cf\u8fdb\u884c\u5206\u88c2\uff0c\u9488\u5bf9\u5f53\u524d\u8fd9\u4e2a\u5206\u88c2\u64cd\u4f5c\uff0c3\uff0c4\u8bb0\u5f55\u4fdd\u7559\u5728\u539f\u6709\u9875\u9762\uff0c5\uff0c6\u8bb0\u5f55\uff0c\u79fb\u52a8\u5230\u65b0\u7684\u9875\u9762\u3002\u6700\u540e\u5c06\u65b0\u7eaa\u5f557\u63d2\u5165\u5230\u65b0\u7684\u9875\u9762\u4e2d\uff1b
\n50%\u5206\u88c2\u7b56\u7565\u7684\u4f18\u52bf\uff1a
\n\u5206\u88c2\u4e4b\u540e\uff0c\u4e24\u4e2a\u9875\u9762\u7684\u7a7a\u95f4\u5229\u7528\u7387\u662f\u4e00\u6837\u7684\uff1b\u5982\u679c\u65b0\u7684\u63d2\u5165\u662f\u968f\u673a\u5728\u4e24\u4e2a\u9875\u9762\u4e2d\u6311\u9009\u8fdb\u884c\uff0c\u90a3\u4e48\u4e0b\u4e00\u6b21\u5206\u88c2\u7684\u64cd\u4f5c\u5c31\u4f1a\u66f4\u665a\u89e6\u53d1\uff1b
\n50%\u5206\u88c2\u7b56\u7565\u7684\u52a3\u52bf\uff1a
\n\u7a7a\u95f4\u5229\u7528\u7387\u4e0d\u9ad8\uff1a\u6309\u7167\u4f20\u7edf50%\u7684\u9875\u9762\u5206\u88c2\u7b56\u7565\uff0c\u7d22\u5f15\u9875\u9762\u7684\u7a7a\u95f4\u5229\u7528\u7387\u572850%\u5de6\u53f3\uff1b
\n\u5206\u88c2\u9891\u7387\u8f83\u5927\uff1a\u9488\u5bf9\u5982\u4e0a\u6240\u793a\u7684\u9012\u589e\u63d2\u5165(\u9012\u51cf\u63d2\u5165)\uff0c\u6bcf\u65b0\u63d2\u5165\u4e24\u6761\u8bb0\u5f55\uff0c\u5c31\u4f1a\u5bfc\u81f4\u6700\u53f3\u7684\u53f6\u9875\u9762\u518d\u6b21\u53d1\u751f\u5206\u88c2\uff1b
\n5. \u4f20\u7edf50%\u5206\u88c2\u7684\u7b56\u7565\uff0c\u6709\u4e0d\u8db3\u4e4b\u5904\uff0c\u5982\u4f55\u4f18\u5316\uff1f\u63a5\u7740\u5f80\u4e0b\u770b\u3002
\n6. B+\u6811\u5206\u88c2\u64cd\u4f5c\u7684\u4f18\u5316\uff1f
\n\u7531\u4e8e\u4f20\u7edf50%\u5206\u88c2\u7684\u7b56\u7565\uff0c\u6709\u4e0d\u8db3\u4e4b\u5904\uff0c\u56e0\u6b64\uff0c\u76ee\u524d\u6240\u6709\u7684\u5173\u7cfb\u578b\u6570\u636e\u5e93\uff0c\u5305\u62ecOracle\/InnoDB\/PostgreSQL\uff0c\u90fd\u9488\u5bf9B+\u6811\u7d22\u5f15\u7684\u9012\u589e\/\u9012\u51cf\u63d2\u5165\u8fdb\u884c\u4e86\u4f18\u5316\u3002\u7ecf\u8fc7\u4f18\u5316\uff0c\u4ee5\u4e0a\u7684B+\u6811\u7d22\u5f15\uff0c\u5728\u8bb0\u5f556\u63d2\u5165\u5b8c\u6bd5\uff0c\u8bb0\u5f557\u63d2\u5165\u5f15\u8d77\u5206\u88c2\u4e4b\u540e\uff0c\u65b0\u7684B+\u6811\u7ed3\u6784\u5982\u4e0b\u56fe\u6240\u793a\uff1a<\/p>\n

\u5bf9\u6bd4\u4e0a\u4e0b\u4e24\u4e2a\u63d2\u5165\u8bb0\u5f557\u4e4b\u540e\uff0cB+\u6811\u7d22\u5f15\u7684\u7ed3\u6784\u56fe\uff0c\u53ef\u4ee5\u53d1\u73b0\u4e8c\u8005\u6709\u5f88\u591a\u7684\u4e0d\u540c\u4e4b\u5904\uff1a<\/p>\n

\u65b0\u7684\u5206\u88c2\u7b56\u7565\uff0c\u5728\u63d2\u51657\u65f6\uff0c\u4e0d\u79fb\u52a8\u539f\u6709\u9875\u9762\u7684\u4efb\u4f55\u8bb0\u5f55\uff0c\u53ea\u662f\u5c06\u65b0\u63d2\u5165\u7684\u8bb0\u5f557\u5199\u5230\u65b0\u9875\u9762\u4e4b\u4e2d\uff1b
\n\u539f\u6709\u9875\u9762\u7684\u5229\u7528\u7387\uff0c\u4ecd\u65e7\u662f100%\uff1b
\n\u4f18\u5316\u5206\u88c2\u7b56\u7565\u7684\u4f18\u52bf\uff1a
\n\u7d22\u5f15\u5206\u88c2\u7684\u4ee3\u4ef7\u5c0f\uff1a\u4e0d\u9700\u8981\u79fb\u52a8\u8bb0\u5f55\uff1b
\n\u7d22\u5f15\u5206\u88c2\u7684\u6982\u7387\u964d\u4f4e\uff1a\u5982\u679c\u63a5\u4e0b\u6765\u7684\u63d2\u5165\uff0c\u4ecd\u65e7\u662f\u9012\u589e\u63d2\u5165\uff0c\u90a3\u4e48\u9700\u8981\u63d2\u51654\u6761\u8bb0\u5f55\uff0c\u624d\u80fd\u518d\u6b21\u5f15\u8d77\u9875\u9762\u7684\u5206\u88c2\u3002\u76f8\u5bf9\u4e8e50%\u5206\u88c2\u7b56\u7565\uff0c\u5206\u88c2\u7684\u6982\u7387\u964d\u4f4e\u4e86\u4e00\u534a\uff1b
\n\u7d22\u5f15\u9875\u9762\u7684\u7a7a\u95f4\u5229\u7528\u7387\u63d0\u9ad8\uff1a\u65b0\u7684\u5206\u88c2\u7b56\u7565\uff0c\u80fd\u591f\u4fdd\u8bc1\u5206\u88c2\u524d\u7684\u9875\u9762\uff0c\u4ecd\u65e7\u4fdd\u6301100%\u7684\u5229\u7528\u7387\uff0c\u63d0\u9ad8\u4e86\u7d22\u5f15\u7684\u7a7a\u95f4\u5229\u7528\u7387\uff1b
\n\u4f18\u5316\u5206\u88c2\u7b56\u7565\u7684\u52a3\u52bf\uff1a
\n\u5982\u679c\u65b0\u7684\u63d2\u5165\uff0c\u4e0d\u518d\u6ee1\u8db3\u9012\u589e\u63d2\u5165\u7684\u6761\u4ef6\uff0c\u800c\u662f\u63d2\u5165\u5230\u539f\u6709\u9875\u9762\uff0c\u90a3\u4e48\u5c31\u4f1a\u5bfc\u81f4\u539f\u6709\u9875\u9762\u518d\u6b21\u5206\u88c2\uff0c\u589e\u52a0\u4e86\u5206\u88c2\u7684\u6982\u7387\u3002<\/p>\n

8. mysql\u7d22\u5f15\u7a76\u7adf\u5982\u4f55\u63d2\u5165\u7684\u5462\uff1f
\n\u5b98\u65b9\u89e3\u8bfb
\n\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014\u2014
\n\u7248\u6743\u58f0\u660e\uff1a\u672c\u6587\u4e3aCSDN\u535a\u4e3b\u300c\u5e0c\u5c24\u300d\u7684\u539f\u521b\u6587\u7ae0\uff0c\u9075\u5faa CC 4.0 BY-SA \u7248\u6743\u534f\u8bae\uff0c\u8f6c\u8f7d\u8bf7\u9644\u4e0a\u539f\u6587\u51fa\u5904\u94fe\u63a5\u53ca\u672c\u58f0\u660e\u3002
\n\u539f\u6587\u94fe\u63a5\uff1ahttps:\/\/blog.csdn.net\/qq_39455116\/java\/article\/details\/86496053<\/p>\n","protected":false},"excerpt":{"rendered":"

\u539f\u6587\u5730\u5740   \u539f\u521b\u5e0c\u5c24 \u6700\u540e\u53d1<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"colormag_page_container_layout":"default_layout","colormag_page_sidebar_layout":"default_layout","footnotes":""},"categories":[],"tags":[118],"class_list":["post-4264","post","type-post","status-publish","format-standard","hentry","tag-02-"],"_links":{"self":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/4264","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/comments?post=4264"}],"version-history":[{"count":0,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/4264\/revisions"}],"wp:attachment":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/media?parent=4264"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/categories?post=4264"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/tags?post=4264"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}