{"id":495,"date":"2024-09-05T03:40:14","date_gmt":"2024-09-04T19:40:14","guid":{"rendered":"https:\/\/forelink.top\/?p=495"},"modified":"2024-09-05T18:03:04","modified_gmt":"2024-09-05T10:03:04","slug":"2-mysql%e7%b4%a2%e5%bc%95x","status":"publish","type":"post","link":"https:\/\/forelink.top\/index.php\/2024\/09\/05\/2-mysql%e7%b4%a2%e5%bc%95x\/","title":{"rendered":"MySQL\u7d22\u5f15"},"content":{"rendered":"\n

\u7b80\u4ecb\uff1a<\/h2>\n\n\n\n

\u7d22\u5f15\uff08index\uff09\u662f\u5e2e\u52a9MySQL\u9ad8\u6548\u83b7\u53d6\u6570\u636e\u7684\u6570\u636e\u7ed3\u6784\uff08\u6709\u5e8f\uff09<\/p>\n\n\n\n

\u5168\u8868\u626b\u63cf\u6027\u80fd\u6781\u4f4e\u3002\n\u5efa\u7acb\u7d22\u5f15\uff0c\u5c31\u662f\u5efa\u7acb\u4e00\u4e2a\u4e8c\u53c9\u6811\u5e76\u7ef4\u62a4\u3002<\/p>\n\n\n\n

\u6709\u7d22\u5f15\u7684\u4f4d\u7f6e\uff0c\u67e5\u8be2\u6548\u7387\u975e\u5e38\u9ad8\u6548\u3002<\/p>\n\n\n\n

\u63d0\u9ad8\u6570\u636e\u68c0\u7d22\u7684\u6548\u7387\uff0c\u964d\u4f4e\u6570\u636e\u5e93IO\u538b\u529b\uff0c\u7528\u7a7a\u95f4\u6362\u65f6\u95f4\u3002\n\u867d\u7136\u67e5\u8be2\u6548\u7387\u5f88\u9ad8\uff0c\u4f46\u5982\u679c\u8fdb\u884c\u66f4\u5220\u6539\u64cd\u4f5c\u65f6\uff0c\u4f1a\u4ea7\u751f\u989d\u5916\u7ef4\u62a4\u6811\u7684\u6210\u672c\u3002<\/p>\n\n\n\n

\u7d22\u5f15\u7ed3\u6784\uff1a<\/h2>\n\n\n\n

\u5728\u5b58\u50a8\u5f15\u64ce\u5c42\u5b9e\u73b0\uff0c\u4e0d\u540c\u5b58\u50a8\u5f15\u64ce\u6709\u4e0d\u540c\u7684\u7ed3\u6784\uff1a<\/p>\n\n\n\n

\"image-20240904172446832\"\/<\/div><\/figure>\n\n\n\n

<\/p>\n\n\n\n

B+\u6811\u662f\u6700\u5e38\u89c1\u7684\u7d22\u5f15\u7c7b\u578b\uff0c\u5927\u90e8\u5206\u5f15\u64ce\u90fd\u652f\u6301B+\u6811\u7d22\u5f15\u3002\nB+tree\u7d22\u5f15\u5bf9\u4e8e\u4e09\u4e2a\u5e38\u7528\u5b58\u50a8\u5f15\u64ce\u90fd\u662f\u652f\u6301\u7684\uff08InnoDB\u3001MyISAM\u3001Memory\uff09<\/p>\n\n\n\n

B\u6811\uff1a<\/h3>\n\n\n\n

B\u6811\u4e3a\u5b58\u53d6\u6570\u636e\u8bbe\u8ba1\u7684\u591a\u8def\u5e73\u8861\u641c\u7d22\u6811\u3002B\u6811\u7c7b\u4f3c\u4e8e\u7ea2\u9ed1\u6811\uff0c\u4f46B\u6811\u5728\u964d\u4f4e\u78c1\u76d8I\/O\u65b9\u9762\u66f4\u597d\u4e00\u4e9b\u3002\u8bb8\u591a\u6570\u636e\u5e93\u90fd\u7528B\u6811\u6216\u8005B\u6811\u53d8\u79cd\u6765\u5b58\u50a8\u6570\u636e\u3002<\/p>\n\n\n\n

B\u6811\u53ef\u4ee5\u5728O(lg(n))\u65f6\u95f4\u5185\u5b8c\u6210\u4e00\u4e9b\u52a8\u6001\u96c6\u5408\u7684\u64cd\u4f5c\u3002<\/p>\n\n\n\n

B\u6811\u6839\u636e\u6700\u5c0f\u5ea6\u6570t\u22652\uff0c\u5bf9\u5305\u542bn\u4e2a\u5173\u952e\u5b57\uff0c\u9ad8\u5ea6\u4e3ah\u7684B\u6811\u6709\uff1a<\/p>\n\n\n\n

\"image-20240904191844336\"\/<\/div><\/figure>\n\n\n\n

<\/p>\n\n\n\n

\u5c42\u7ea7\u76f8\u8f83\u4e8e\u7ea2\u9ed1\u6811\u5c11\uff0c\u66f4\u9002\u5408\u4e8e\u5927\u6570\u636e\u91cfIO\n$$\nh\u2264log _{t} \\frac{n+1}{2}\n$$<\/p>\n\n\n\n

B+\u6811\uff1a<\/h3>\n\n\n\n

\u6700\u5e38\u89c1\u7684B\u6811\u53d8\u79cd\u4e4b\u4e00\uff0c\u5b83\u628a\u6240\u6709\u536b\u661f\u6570\u636e\u90fd\u5b58\u50a8\u5728\u53f6\u8282\u70b9\u4e2d\uff0c\u5185\u90e8\u7ed3\u70b9\u53ea\u5b58\u653e\u5173\u952e\u5b57\u548c\u5b69\u5b50\u6307\u9488\uff0c\u56e0\u6b64\u6700\u5927\u5316\u4e86\u5185\u90e8\u7ed3\u70b9\u7684\u5206\u652f\u56e0\u5b50\u3002<\/p>\n\n\n\n

MySQL\u5bf9B+\u6811\u8fdb\u884c\u4e86\u4f18\u5316\uff0c\u589e\u52a0\u4e86\u4e00\u4e2a\u6307\u5411\u76f8\u90bb\u53f6\u5b50\u8282\u70b9\u7684\u94fe\u8868\u6307\u9488\uff0c\u5f62\u6210\u4e86\u6709\u5e8f\u6307\u9488\u7684B+Tree\uff0c\u63d0\u9ad8\u4e86\u533a\u95f4\u8bbf\u95ee\u7684\u6027\u80fd\u3002<\/p>\n\n\n\n

\"image-20240904194346540\"\/<\/div><\/figure>\n\n\n\n

<\/p>\n\n\n\n

Hash\uff1a<\/h3>\n\n\n\n

\u54c8\u5e0c\u7d22\u5f15\u91c7\u7528hash\u7b97\u6cd5\uff0c\u5c06key-value\u6362\u7b97\u6210\u65b0\u7684hash\u503c\uff0c\u6620\u5c04\u5230\u5bf9\u5e94\u7684\u69fd\u4f4d\u4e0a\uff0c\u5b58\u50a8\u5728hash\u8868\u3002\u51fa\u73b0hash\u51b2\u7a81\u65f6\uff0c\u5c06hash\u8868\u7684value\u6539\u9020\u6210\u94fe\u8868\u3002<\/p>\n\n\n\n

Hash\u7d22\u5f15\u67e5\u8be2\u6548\u7387\u9ad8\uff0c\u7406\u60f3\u60c5\u51b5\u7684\u65f6\u95f4\u590d\u6742\u5ea6\u4e3aO(1)\u3002<\/p>\n\n\n\n

Hash\u7d22\u5f15\u53ea\u80fd\u7528\u4e8e\u5339\u914d\uff08=\uff09\uff0c\u4e0d\u652f\u6301\u8303\u56f4\u67e5\u8be2\uff08between, < , > )\n\u4e14Hash\u7d22\u5f15\u65e0\u6cd5\u5b8c\u6210\u6392\u5e8f\u64cd\u4f5c\u3002<\/p>\n\n\n\n

\u9664\u4e86Memory\u5916\uff0cInnoDB\u6709\u81ea\u9002\u5e94hash\u7d22\u5f15\u7684\u529f\u80fd\u3002<\/p>\n\n\n\n

\u7d22\u5f15\u5206\u7c7b\uff1a<\/h2>\n\n\n\n

\u805a\u96c6\u7d22\u5f15\u548c\u4e8c\u7ea7\u7d22\u5f15\uff1a<\/h3>\n\n\n\n

InnoDB\u4e2d\uff1a\n\u805a\u96c6\u7d22\u5f15\uff1a\u5c06\u6570\u636e\u4e0e\u7d22\u5f15\u5171\u540c\u5b58\u50a8\uff0c\u7d22\u5f15\u7ed3\u6784\u7684\u53f6\u5b50\u8282\u70b9\u4fdd\u5b58\u4e86\u884c\u6570\u636e\u3002\n\u4e8c\u7ea7\u7d22\u5f15\uff1a\u6570\u636e\u4e0e\u7d22\u5f15\u5206\u5f00\u5b58\u50a8\uff0c\u7d22\u5f15\u7ed3\u6784\u7684\u53f6\u5b50\u8282\u70b9\u5173\u8054\u7684\u662f\u5bf9\u5e94\u7684\u4e3b\u952e<\/p>\n\n\n\n

\u805a\u96c6\u7d22\u5f15\u6709\u4e14\u4ec5\u6709\u4e00\u4e2a\n\u4e8c\u7ea7\u7d22\u5f15\u53ef\u4ee5\u5b58\u5728\u591a\u4e2a<\/p>\n\n\n\n

\u805a\u96c6\u7d22\u5f15\u9009\u53d6\u89c4\u5219\uff1a\n\u5982\u679c\u5b58\u5728\u4e3b\u952e\uff0c\u4e3b\u952e\u7d22\u5f15\u5c31\u662f\u805a\u96c6\u7d22\u5f15\u3002\n\u5982\u679c\u4e0d\u5b58\u5728\u4e3b\u952e\uff0c\u5c06\u4f7f\u7528\u7b2c\u4e00\u4e2a\u552f\u4e00\u7d22\u5f15\uff08UNIQUE\uff09\u4f5c\u4e3a\u805a\u96c6\u7d22\u5f15\u3002\n\u5982\u679c\u6ca1\u6709\u5408\u9002\u7684\u552f\u4e00\u7d22\u5f15\uff0cInnoDB\u4f1a\u81ea\u52a8\u751f\u6210\u4e00\u4e2a\u9690\u85cf\u7684rowid\u4f5c\u4e3a\u805a\u96c6\u7d22\u5f15<\/p>\n\n\n\n

\u805a\u96c6\u7d22\u5f15\uff1a\u53f6\u8282\u70b9\u5b58\u653e\u884c\u6570\u636e\u3002<\/p>\n\n\n\n

\"image-20240904194346540\"\/<\/div><\/figure>\n\n\n\n

<\/p>\n\n\n\n

\u4e8c\u7ea7\u7d22\u5f15\uff1a\u53f6\u8282\u70b9\u5b58\u653e\u4e3b\u952e<\/p>\n\n\n\n

\"image-20240904194523710\"\/<\/div><\/figure>\n\n\n\n

<\/p>\n\n\n\n

\u7528\u4e8c\u7ea7\u7d22\u5f15\u67e5\u5230\u7684\u4e3b\u952e\u503c\uff0c\u5728\u805a\u96c6\u7d22\u5f15\u4e2d\u67e5\u8be2\u884c\u6570\u636e\u503c\uff0c\u8fd9\u79cd\u64cd\u4f5c\u53eb\u56de\u8868\u67e5\u8be2\u3002\n\u5927\u90e8\u5206SQL\u4f18\u5316\uff0c\u90fd\u4f9d\u8d56\u4e8e\u805a\u96c6\u7d22\u5f15\u548c\u4e8c\u7ea7\u7d22\u5f15\u7ed3\u6784\u548c\u539f\u7406\u7684\u7406\u89e3\u3002<\/p>\n\n\n\n

\u7d22\u5f15\u64cd\u4f5c\u8bed\u6cd5\uff1a<\/h2>\n\n\n\n

\u521b\u5efa\u7d22\u5f15\uff1a<\/h3>\n\n\n\n
\/\/ \u4e0d\u6307\u5b9a\u7d22\u5f15\u7c7b\u578b \u9ed8\u8ba4\u521b\u5efa\u5e38\u89c4\u7d22\u5f15\nCREATE [UNIQUE|FULLTEXT] INDEX index_name ON [table_name] (col_name...)\n<\/code><\/pre>\n\n\n\n
\u67e5\u770b\u7d22\u5f15\uff1a<\/h3>\n\n\n\n
SHOW INDEX FROM table_name;\n<\/code><\/pre>\n\n\n\n
\u5220\u9664\u7d22\u5f15\uff1a<\/h3>\n\n\n\n
DROP INDEX [index_name] ON [table_name];\n<\/code><\/pre>\n\n\n\n
\u4f8b\uff1a<\/h3>\n\n\n\n
name\u5b57\u6bb5\u4e3a\u59d3\u540d\u5b57\u6bb5\uff0c\u8be5\u5b57\u6bb5\u7684\u503c\u53ef\u80fd\u4f1a\u91cd\u590d\uff0c\u4e3a\u8be5\u5b57\u6bb5\u521b\u5efa\u7d22\u5f15\u3002<\/p>\n\n\n\n
phone\u624b\u673a\u53f7\u5b57\u6bb5\u7684\u503c\uff0c\u975e\u7a7a\uff0c\u552f\u4e00\u3002\u4e3a\u8be5\u6bb5\u5efa\u7acb\u552f\u4e00\u7d22\u5f15\u3002<\/p>\n\n\n\n
job\uff0cage \u8bbe\u8054\u5408\u7d22\u5f15\u3002<\/p>\n\n\n\n
\/\/ \u8054\u5408\u7d22\u5f15\u7684\u5b57\u6bb5\u987a\u5e8f \ncreate index [index_name] on [table_name] (\u5b57\u6bb51\uff0c\u5b57\u6bb52...)\n<\/code><\/pre>\n\n\n\n
SQL\u6027\u80fd\u5206\u6790\uff1a<\/h2>\n\n\n\n
\u505aSQL\u5206\u6790\uff0c\u9700\u8981\u505aSQL\u6027\u80fd\u5206\u6790\u3002<\/p>\n\n\n\n
SQL\u6267\u884c\u9891\u7387\uff1a<\/h3>\n\n\n\n
\u67e5\u770b\u5f53\u524d\u670d\u52a1\u5668\u72b6\u6001\u4fe1\u606f<\/p>\n\n\n\n
show [session|global] status;\n<\/code><\/pre>\n\n\n\n
\u5e38\u7528\u7684\u547d\u4ee4<\/p>\n\n\n\n
\/\/ \u4e03\u4e2a\u4e0b\u5212\u7ebf\nshow [session|global] status like 'com_______';\n<\/code><\/pre>\n\n\n\n
\"image-20240904203907968\"\/<\/div><\/figure>\n\n\n\n
<\/p>\n\n\n\n
\u53cd\u6094\u4e86\u6240\u6709\u64cd\u4f5c\u7684\u8bbf\u95ee\u9891\u6b21\uff0c\u4e3aSQL\u6027\u80fd\u4f18\u5316\u63d0\u4f9b\u51b3\u7b56\u57fa\u7840\u3002<\/p>\n\n\n\n
\u6162\u67e5\u8be2\u65e5\u5fd7\uff1a<\/h3>\n\n\n\n
\u6162\u67e5\u8be2\u65f6\u95f4\u8bb0\u5f55\u4e86\u6240\u6709\u6267\u884c\u65f6\u95f4\u8d85\u8fc7\u6307\u5b9a\u53c2\u6570long_query_time\u7684\u6240\u6709SQL\u8bed\u53e5\u7684\u65e5\u5fd7\uff08\u9ed8\u8ba410\u79d2\uff09<\/p>\n\n\n\n
\u6570\u636e\u5e93\u7684\u6162\u67e5\u8be2\u65e5\u5fd7\uff0c\u9ed8\u8ba4\u6ca1\u6709\u5f00\u542f\uff0c\u9700\u8981\u5728MySQL\u7684\u914d\u7f6e\u6587\u4ef6(\u5982\uff1a\/etc\/mysql\/my.cnf)\u4e2d\u6dfb\u52a0\u4ee5\u4e0b\u914d\u7f6e\u4fe1\u606f\uff1a<\/p>\n\n\n\n
#\u5206\u914d\u4e00\u4e2a\u914d\u7f6e\u7ec4\n[mysqld]\n#\u5f00\u542fMySQL\u6162\u65e5\u5fd7\u67e5\u8be2\u5f00\u5173\nslow_query_log = 1\n#\u8bbe\u7f6e\u6162\u65e5\u5fd7\u65f6\u95f4 SQL\u8bed\u53e5\u6267\u884c\u65f6\u95f4\u8d85\u8fc7time\uff0c\u5c31\u4f1a\u88ab\u8bb0\u5f55\u5230\u6162\u67e5\u8be2\u65e5\u5fd7\u4e2d\nlong_query_time = time\n#\u8bbe\u7f6e\u6162\u65e5\u5fd7\u5b58\u50a8\u4f4d\u7f6e\u548c\u6162\u65e5\u5fd7\u6587\u4ef6\u540d\nslow_query_log_file = \/var\/lib\/mysql\/xxx-slow.log\n<\/code><\/pre>\n\n\n\n
\u8f93\u5165 show variables like ‘slow_query_log’ \u67e5\u770b\u5f53\u524d\u6162\u65e5\u5fd7\u5f00\u542f\u60c5\u51b5<\/p>\n\n\n\n
\"image-20240904212051965\"\/<\/div><\/figure>\n\n\n\n
<\/p>\n\n\n\n
\u65e5\u5fd7\u6587\u4ef6\u9ed8\u8ba4\u751f\u6210\u5728 \/var\/lib\/mysql \u76ee\u5f55\u4e0b<\/p>\n\n\n\n
\u7528tail -f xxx-slow.log \u6765\u76d1\u89c6\u6587\u4ef6\u53d8\u52a8\uff0c\u53ef\u4ee5\u6d4b\u8bd5\u6162\u67e5\u8be2\u65e5\u5fd7\uff0c\u6765\u5b9a\u4f4d\u6267\u884c\u6548\u7387\u6bd4\u8f83\u4f4e\u7684SQL\u3002<\/p>\n\n\n\n
\"image-20240905162241638\"\/<\/div><\/figure>\n\n\n\n
<\/p>\n\n\n\n
profile\u8be6\u60c5\uff1a<\/h3>\n\n\n\n
\u5982\u679c\u6211\u4eec\u60f3\u5173\u6ce8\u6bd4\u6162\u67e5\u8be2\u65e5\u5fd7\u7565\u6162\u7684SQL\u8bed\u53e5<\/p>\n\n\n\n
show profiles\u80fd\u5728\u505aSQL\u4f18\u5316\u524d\uff0c\u8ba9\u6211\u4eec\u77e5\u9053\u65f6\u95f4<\/p>\n\n\n\n
\/\/ \u67e5\u770b\u662f\u5426\u652f\u6301profiles\nSELECT @@have_profiling;\n\/\/ \u67e5\u770b\u662f\u5426\u5f00\u542fprofiling\nSELECT @@profiling;\n\/\/ \u5f00\u542fprofiling\nset profiling = 1;\n<\/code><\/pre>\n\n\n\n
\"image-20240904212632560\"\/<\/div><\/figure>\n\n\n\n
<\/p>\n\n\n\n
\u8bf4\u660e\u652f\u6301profile\uff0c\u4f46profiling\u9ed8\u8ba4\u662f\u5173\u95ed\u7684\uff0c\u9700\u8981\u6211\u4eec\u624b\u52a8\u7684\u6253\u5f00\u3002<\/p>\n\n\n\n
\"image-20240904212752806\"\/<\/div><\/figure>\n\n\n\n
<\/p>\n\n\n\n
\"image-20240904212847209\"\/<\/div><\/figure>\n\n\n\n
<\/p>\n\n\n\n
\u901a\u8fc7show profiles\u547d\u4ee4\u53ef\u4ee5\u67e5\u770b\u6240\u6709\u547d\u4ee4\u7684\u8017\u65f6\u60c5\u51b5\u3002<\/p>\n\n\n\n
\/\/ \u67e5\u8be2profiles\nshow profiles;\n\/\/ \u67e5\u8be2\u4e00\u6761\u547d\u4ee4\u7684\u5177\u4f53\u8017\u65f6 profile\u6ca1\u6709s\n\/\/ \u52a0\u5165cpu\u540e \u53ef\u4ee5\u67e5\u770b\u6bcf\u4e2a\u9636\u6bb5\u7684cpu\u5360\u7528\u60c5\u51b5\nshow profile [cpu] for query [Query_ID];\n<\/code><\/pre>\n\n\n\n
\"image-20240904213152056\"\/<\/div><\/figure>\n\n\n\n
<\/p>\n\n\n\n
\u540c\u65f6\u4e5f\u53ef\u4ee5\u67e5\u8be2\u4e00\u6761\u547d\u4ee4\u7684\u5177\u4f53\u8017\u65f6\uff1a<\/p>\n\n\n\n
\"image-20240904213402224\"\/<\/div><\/figure>\n\n\n\n
<\/p>\n\n\n\n
explain\u6267\u884c\u8ba1\u5212\uff1a<\/h3>\n\n\n\n
EXPLAIN \u6216\u8005 DESC\u547d\u4ee4\u83b7\u53d6MySQL\u5982\u4f55<\/p>\n\n\n\n
EXPLAIN\u548cDESC\u6548\u679c\u662f\u4e00\u6837\u7684<\/p>\n\n\n\n
\"image-20240904214316209\"\/<\/div><\/figure>\n\n\n\n
<\/p>\n\n\n\n
\u5404\u5b57\u6bb5\u542b\u4e49\uff1a<\/p>\n\n\n\n
Id\uff1a\n    \u8868\u793a\u67e5\u8be2\u7684\u8868\u987a\u5e8f\uff0c\u8868\u793a\u4e86\u64cd\u4f5c\u8868\u7684\u6267\u884c\u987a\u5e8f\u3002\n    \uff08id\u76f8\u540c\uff0c\u6267\u884c\u987a\u5e8f\u4ece\u4e0a\u5230\u4e0b\u3002id\u4e0d\u540c\uff0c\u503c\u8d8a\u5927\u8d8a\u5148\u6267\u884c\u3002\uff09<\/p>\n\n\n\n
select_type\uff1a\n    \u8868\u793aSELECT\u7684\u7c7b\u578b\uff0c\u5e38\u89c1\u7684\u53d6\u503c\u6709\n        Simple    \uff08\u7b80\u5355\u8868\uff0c\u5373\u4e0d\u7528\u8868\u8fde\u63a5\u6216\u5b50\u67e5\u8be2\uff09\n        Primary    \uff08\u4e3b\u67e5\u8be2\uff0c\u5373\u6700\u5916\u5c42\u7684\u67e5\u8be2\uff09\n        Union      \uff08UNION\u4e2d\u7b2c\u4e00\u4e2a\u4e4b\u540e\u7684\u67e5\u8be2\u8bed\u53e5\uff09\n        Subquery \uff08SELECT\/WHERE \u4e4b\u540e\u7684\u5b50\u67e5\u8be2\uff09<\/p>\n\n\n\n
type\uff1a\n    \u8868\u793a\u8fde\u63a5\u7c7b\u578b\uff0c\u6027\u80fd\u7531\u9ad8\u5230\u4f4e\u7684\u8fde\u63a5\u7c7b\u578b\u4e3a\n    NULL , system , const , eq_ref , ref , range , index , all\n    NULL\u5728\u4e00\u822c\u4e1a\u52a1\u64cd\u4f5c\u4e2d\u4e00\u822c\u4e0d\u592a\u53ef\u80fd\u51fa\u73b0\u3002\n    all\u4ee3\u8868\u5168\u8868\u626b\u63cf\uff0c\u662f\u6027\u80fd\u6700\u5dee\u7684\u67e5\u8868\u65b9\u5f0f\u3002\n    \u5176\u4f59\u5404\u8fde\u63a5\u7c7b\u578b\u73b0\u67e5\u5373\u53ef\u3002<\/p>\n\n\n\n
possible_key\uff1a\n    \u663e\u793a\u53ef\u80fd\u5e94\u7528\u5728\u8fd9\u5f20\u8868\u4e0a\u7684\u7d22\u5f15\u3002<\/p>\n\n\n\n
Key\uff1a\n    \u5b9e\u9645\u4f7f\u7528\u7684\u7d22\u5f15\uff0c\u4e3aNULL\u65f6\u6ca1\u6709\u4f7f\u7528\u7d22\u5f15<\/p>\n\n\n\n
Key_len\uff1a\n    \u8868\u793a\u7d22\u5f15\u4e2d\u4f7f\u7528\u7684\u5b57\u8282\u6570\uff0c\u4e3a\u7d22\u5f15\u5b57\u6bb5\u6700\u5927\u53ef\u80fd\u957f\u5ea6\uff0c\u5e76\u975e\u5b9e\u9645\u4f7f\u7528\u957f\u5ea6\u3002\n    \u5728\u4e0d\u635f\u5931\u7cbe\u786e\u6027\u7684\u524d\u63d0\u4e0b\uff0c\u957f\u5ea6\u8d8a\u77ed\u8d8a\u597d\u3002<\/p>\n\n\n\n
rows\uff1a\n    MySQL\u9884\u4f30\u5fc5\u9700\u8981\u6267\u884c\u67e5\u8be2\u7684\u884c\u6570\uff0c\u5728InnoDB\u5f15\u64ce\u7684\u8868\u4e2d\u662f\u4e00\u4e2a\u4f30\u8ba1\u503c\u3002<\/p>\n\n\n\n
filtered\uff1a\n    \u8868\u793a\u8fd4\u56de\u7ed3\u679c\u7684\u884c\u6570\u5360\u9700\u8bfb\u53d6\u884c\u6570\u7684\u767e\u5206\u6bd4\uff0cfiltered\u7684\u503c\u8d8a\u5927\u8d8a\u597d\u3002<\/p>\n\n\n\n
Extra\uff1a\n    \u989d\u5916\u7684\u503c\uff0c\u524d\u9762\u6ca1\u6709\u5c55\u793a\u51fa\u6765\u7684\u503c\u4f1a\u5728\u6b64\u663e\u793a\u3002<\/p>\n\n\n\n
type\uff0cpossible_keys\uff0ckey\uff0ckey_len\uff0c\u662f\u6700\u91cd\u8981\u7684\u8fd4\u56de\u503c\u3002<\/p>\n\n\n\n
\u7d22\u5f15\u4f7f\u7528\uff1a<\/h2>\n\n\n\n
\u9a8c\u8bc1\u7d22\u5f15\u6548\u7387\uff1a<\/h3>\n\n\n\n
\u4f7f\u7528\u4e3b\u952e\u67e5\u8be2\u548c\u975e\u4e3b\u952e\u67e5\u8be2\u65f6\uff0c\u6027\u80fd\u4f1a\u6709\u5f88\u5927\u7684\u5dee\u5f02\u3002\n\u4e3b\u952e\u9ed8\u8ba4\u6709\u4e3b\u952e\u7d22\u5f15\uff0c\u5176\u4ed6key\u9700\u8981\u81ea\u884c\u521b\u5efa\u7d22\u5f15\u3002<\/p>\n\n\n\n
\u521b\u5efa\u7d22\u5f15\u9700\u8981\u6784\u5efa\u4e00\u4e2aB+\u6811\u7684\u6570\u636e\u7ed3\u6784\u3002\u9700\u8981\u8f83\u957f\u7684\u65f6\u95f4\u3002<\/p>\n\n\n\n
\u672a\u521b\u5efa\u7d22\u5f15\uff1a<\/h4>\n\n\n\n
\u5728\u6570\u636e\u91cf\u4e3a1e7\u65f6\uff0c\u65e0\u7d22\u5f15\u67e5\u8be2\u65f6\u95f4\u7ea6\u4e3a8.92s<\/p>\n\n\n\n
\"image-20240905162434927\"\/<\/div><\/figure>\n\n\n\n
<\/p>\n\n\n\n
\u5df2\u521b\u5efa\u7d22\u5f15\uff1a<\/h4>\n\n\n\n
\u521b\u5efa\u7d22\u5f15\u540e\uff0c\u67e5\u8be2\u65f6\u95f4\u4e3a0.01s\u3002\u9a8c\u8bc1\u4e86\u7d22\u5f15\u67e5\u8be2\u7684\u6548\u7387\u3002<\/p>\n\n\n\n
\"image-20240905162549795\"\/<\/div><\/figure>\n\n\n\n
<\/p>\n\n\n\n
\u540c\u65f6\u7528explain\u8bed\u53e5\u67e5\u8be2SQL\u6267\u884c\u8ba1\u5212\uff1a<\/p>\n\n\n\n
\"image-20240905162805558\"\/<\/div><\/figure>\n\n\n\n
<\/p>\n\n\n\n
\u4f7f\u7528\u7684key\u4e3a\u7d22\u5f15\u3002<\/p>\n\n\n\n
\u4f7f\u7528\u89c4\u5219\uff1a<\/h3>\n\n\n\n
\u6700\u5de6\u524d\u7f00\u6cd5\u5219\uff1a<\/h4>\n\n\n\n
\u6700\u5de6\u524d\u7f00\u6cd5\u5219\u6307\u7684\u662f\uff0c\u67e5\u8be2\u4ece\u521b\u5efa\u7d22\u5f15\u65f6\u7684\u6700\u5de6\u5217\u5f00\u59cb\uff0c\u5e76\u4e14\u4e0d\u8df3\u8fc7\u7d22\u5f15\u4e2d\u7684\u5217\n\u5982\u679c\u7d22\u5f15\u4e86\u591a\u5217\uff08\u8054\u5408\u7d22\u5f15\uff09\uff0c\u8981\u9075\u5faa\u6700\u5de6\u524d\u7f00\u6cd5\u5219\u3002<\/p>\n\n\n\n
\u5728\u521b\u5efa\u8054\u5408\u7d22\u5f15\u65f6\uff0c\u5047\u8bbe\u5b57\u6bb5\u7684\u987a\u5e8f\u4e3a (i1,i2,i3)<\/p>\n\n\n\n
\/\/ SQL\u4f1a\u4f7f\u7528\u7d22\u5f15\nselect * from t1 where i1 = 'a' and i2 = 'a' and i3 = 'a';\nselect * from t1 where i1 = 'a' and i2 = 'a';\nselect * from t1 where i1 = 'a';\n\n\/\/ \u4e0b\u9762\u7684SQL\u7d22\u5f15\u4f1a\u5931\u6548\nselect * from t1 where i2 = 'a',i3 = 'a';\nselect * from t1 where i2 = 'a';\nselect * from t1 where i3 = 'a';\n\n\/\/ \u4e0b\u9762\u7684SQL\uff0c\u7d22\u5f15\u4f1a\u90e8\u5206\u5931\u6548\nselect * from t1 where i1 = 'a' and i3 = 'a'; \/\/ i3\u5b57\u6bb5\u7684\u7d22\u5f15\u4f1a\u5931\u6548\n<\/code><\/pre>\n\n\n\n
MySQL\u8bed\u6cd5\u4f18\u5316\u5668\u4f1a\u4e3a\u6211\u4eec\u4f18\u5316\u3002<\/p>\n\n\n\n
\u5982\u679c\u4f7f\u7528\u8303\u56f4\u67e5\u8be2\uff08>,<\uff09\uff0c\u4f7f\u7528\u4e86\u8303\u56f4\u67e5\u8be2\u53f3\u4fa7\uff08\u540e\u7eed\u5217\uff09\u7684\u5b57\u6bb5\u7d22\u5f15\u5931\u6548\u3002<\/p>\n\n\n\n
\u8986\u76d6\u7d22\u5f15\uff1a<\/h4>\n\n\n\n
\u67e5\u8be2\u6240\u6709\u5b57\u6bb5\u53ef\u4ee5\u5c06\u6240\u6709\u7d22\u5f15\u90fd\u7528\u4e0a\u7684\u60c5\u51b5\u3002\uff08\uff1f\uff09\n\u5c3d\u91cf\u4f7f\u7528\u8986\u76d6\u7d22\u5f15\uff0c\u51cf\u5c11select * \u7684\u4f7f\u7528\u3002<\/p>\n\n\n\n
\u5982\u679c\u4f7f\u7528\u4e8c\u7ea7\u7d22\u5f15\u67e5\u627e\u65f6\uff0c\u6709\u4e8c\u7ea7\u7d22\u5f15\u4e2d\u4e0d\u5b58\u5728\u7684\u5b57\u6bb5\u3002\n\u5219\u8fd8\u9700\u8981\u56de\u8868\u67e5\u8be2\uff0c\u5728\u805a\u96c6\u7d22\u5f15\u4e2d\u67e5\u627e\u6574\u5217\u4ee5\u83b7\u53d6\u5b57\u6bb5\u7684\u503c\u3002<\/p>\n\n\n\n
\u8054\u5408\u7d22\u5f15 \u53ef\u4ee5\u89e3\u51b3\u591a\u5b57\u6bb5\u67e5\u8be2\u65f6\u56de\u8868\u67e5\u8be2\u7684\u95ee\u9898\u3002<\/p>\n\n\n\n
\u524d\u7f00\u7d22\u5f15\uff1a<\/h4>\n\n\n\n
\u5f53\u5b57\u6bb5\u7c7b\u578b\u4e3a\u5b57\u7b26\u4e32(varchat , text\u7b49)\u65f6\uff0c\u6709\u65f6\u5019\u9700\u8981\u7d22\u5f15\u5f88\u957f\u7684\u5b57\u7b26\u4e32\uff0c\u4f1a\u8ba9\u7d22\u5f15\u53d8\u5f97\u5f88\u5927\u3002\n\u67e5\u8be2\u65f6\u4f1a\u9020\u6210\u5927\u91cf\u78c1\u76d8I\/O,\u5f71\u54cd\u67e5\u8be2\u6548\u7387\u3002\n\u4f7f\u7528\u6a21\u62df\u54c8\u5e0c\u7d22\u5f15\uff0c\u53cd\u800c\u53ef\u80fd\u5bfc\u81f4\u7d22\u5f15\u53d8\u5f97\u66f4\u957f\u3002<\/p>\n\n\n\n
\u6b64\u65f6\u53ef\u4ee5\u53ea\u5c06\u5b57\u7b26\u4e32\u7684\u4e00\u90e8\u5206\u524d\u7f00\uff0c\u5efa\u7acb\u7d22\u5f15\uff0c\u8fd9\u6837\u53ef\u4ee5\u5927\u5927\u8282\u7ea6\u7d22\u5f15\u7a7a\u95f4\uff0c\u63d0\u9ad8\u7d22\u5f15\u6548\u7387\uff08\u5b57\u5178\u6811\uff1f\uff09<\/p>\n\n\n\n
\u8bed\u6cd5\uff1a<\/p>\n\n\n\n
\/\/ \u6839\u636e\u8be5\u5b57\u6bb5\u7684\u524d\u7f00\u957f\u5ea6n \u8bbe\u7f6e\u7d22\u5f15\uff0c\u53ea\u8bb0\u5f55\u8be5\u5b57\u6bb5\u7684\u524dn\u4f4d\nCREATE index idx_xxx on table_name(\u5b57\u6bb5(n))\n<\/code><\/pre>\n\n\n\n
\u524d\u7f00\u957f\u5ea6 \u53ef\u4ee5\u6839\u636e\u7d22\u5f15\u7684\u9009\u62e9\u6027\u6765\u51b3\u5b9a\u3002\n\u6c42\u53d6\u7d22\u5f15\u7684\u9009\u62e9\u6027\uff0c\u9700\u8981\u77e5\u9053\u5b57\u6bb5\u4e0d\u91cd\u590d\u7684\u503c\uff0c\u548c\u8868\u4e2d\u8bb0\u5f55\u884c\u7684\u603b\u6570\u3002<\/p>\n\n\n\n
\/\/ \u5b57\u6bb5\u53bb\u91cd\u540e\u4e0d\u91cd\u590d\u7684\u603b\u8ba1\u6570 C\nselect count(distinct \u5b57\u6bb5) from t1;\n\/\/ \u8868\u4e2d\u884c\u603b\u6570 T\nselect count(*) from t1;\n\n\/\/ \u622a\u53d6\u524dn\u4e2a\u503c\u7684\u7d22\u5f15\u7684\u9009\u62e9\u6027\u4e3a C\/T in n;\nselect count(distinct Left(X,n))\/count(*) from T1;\n<\/code><\/pre>\n\n\n\n
\u53ef\u4ee5\u5f97\u5230\u4e0d\u540c\u524d\u7f00\u957f\u5ea6\u65f6\u7684\u7d22\u5f15\u9009\u62e9\u6027\u3002\u5f53\u6027\u80fd\u63d0\u5347\u4e0d\u660e\u663e\u65f6\uff0c\u9009\u62e9\u4e00\u4e2a\u8f83\u77ed\uff0c\u9009\u62e9\u6027\u591f\u9ad8\u7684\u622a\u53d6\u5ea6\u4f5c\u4e3a\u524d\u7f00\u957f\u5ea6\u5373\u53ef\u3002<\/p>\n\n\n\n
\"image-20240905174228333\"\/<\/div><\/figure>\n\n\n\n
<\/p>\n\n\n\n
\u5f15\u5165\u6982\u5ff5 \u7d22\u5f15\u7684\u9009\u62e9\u6027\n\u8bb0c\u4e3a\u5b57\u6bb5\u4e0d\u91cd\u590d\u7684\u503c\uff0cT\u4e3a\u6570\u636e\u8868\u7684\u8bb0\u5f55\u603b\u6570\n\u7d22\u5f15\u7684\u9009\u62e9\u6027\u4e3a c\/T \uff081\/T ~1)\n\u7d22\u5f15\u7684\u9009\u62e9\u6027\u8d8a\u9ad8\uff0c\u67e5\u8be2\u6548\u7387\u8d8a\u9ad8\uff0c\u56e0\u4e3a\u9009\u62e9\u6027\u9ad8\u53ef\u4ee5MySQL\u5728\u67e5\u627e\u65f6\u8fc7\u6ee4\u6389\u66f4\u591a\u7684\u884c\u3002\n\u552f\u4e00\u7d22\u5f15\u7684\u9009\u62e9\u6027\u4e3a1\u65f6\uff0c\u6027\u80fd\u662f\u6700\u597d\u7684\u3002\n<\/code><\/pre>\n\n\n\n
\u5355\u5217\u7d22\u5f15\u548c\u8054\u5408\u7d22\u5f15\uff1a<\/h4>\n\n\n\n
\u5355\u5217\u7d22\u5f15\uff1a\u4e00\u4e2a\u7d22\u5f15\u53ea\u5305\u542b\u5355\u4e2a\u5217\n\u5bb9\u6613\u6d89\u53ca\u56de\u8868\u67e5\u8be2\u3002<\/p>\n\n\n\n
\u8054\u5408\u7d22\u5f15\uff1a\u4e00\u4e2a\u7d22\u5f15\u5305\u542b\u591a\u4e2a\u5217\uff0c\u53f6\u8282\u70b9\u5b58\u50a8\u536b\u661f\u6570\u636e\n\u5982\u679c\u5b58\u5728\u591a\u4e2a\u67e5\u8be2\u6761\u4ef6\uff0c\u8003\u8651\u9488\u5bf9\u67e5\u8be2\u5b57\u6bb5\u5efa\u7acb\u8054\u5408\u7d22\u5f15\u3002\n\u6765\u907f\u514d\u56de\u8868\u67e5\u8be2\u7684\u989d\u5916\u6027\u80fd\u5f00\u9500\u3002<\/p>\n\n\n\n
\u7d22\u5f15\u5931\u6548\u89c4\u5219\uff1a<\/h3>\n\n\n\n
\u5b57\u7b26\u4e32\uff1a<\/h4>\n\n\n\n
\u683c\u5f0f\u4e0d\u89c4\u8303\uff0c\u6761\u4ef6\u67e5\u8be2\u5b57\u7b26\u4e32\u7c7b\u578b\u5b57\u6bb5\u65f6\u4e0d\u52a0\u5355\u5f15\u53f7\u3002\u6d89\u53ca\u7c7b\u578b\u8f6c\u6362\uff0c\u5bfc\u81f4\u7d22\u5f15\u5931\u6548\u3002\n\u5c3e\u90e8\u6a21\u7cca\u5339\u914d\uff0c\u7d22\u5f15\u4e0d\u4f1a\u5931\u6548\u3002\u5934\u90e8\u6a21\u7cca\u5339\u914d\uff0c\u7d22\u5f15\u4f1a\u5931\u6548\u3002<\/p>\n\n\n\n
\/\/ \u7d22\u5f15\u751f\u6548\nselect * from t1 where phone = '123';\nselect * from t1 where phone like '12%';\n\/\/ \u7d22\u5f15\u5931\u6548\nselect * from t1 where phone = 123;\nselect * from t1 where phone = '%23';\n<\/code><\/pre>\n\n\n\n
or \u8fde\u63a5\u6761\u4ef6\uff1a<\/h4>\n\n\n\n
\u7528 | \uff08or\uff09 \u5206\u5272\u5f00\u7684\u6761\u4ef6\uff0c\u5982\u679c or \u524d\u7684\u6761\u4ef6\u4e2d\u7684\u5217\u6709\u7d22\u5f15\uff0c\u800c\u540e\u9762\u7684\u5217\u4e2d\u6ca1\u6709\u7d22\u5f15\uff0c\u6d89\u53ca\u7684\u7d22\u5f15\u90fd\u4e0d\u4f1a\u88ab\u7528\u5230<\/p>\n\n\n\n
select * from t1 where indexed = 1 or notindexed = 1;\n<\/code><\/pre>\n\n\n\n
\"image-20240905165247414\"\/<\/div><\/figure>\n\n\n\n
<\/p>\n\n\n\n
\u6570\u636e\u5206\u5e03\u5f71\u54cd\uff1a<\/h4>\n\n\n\n
\u5982\u679cMySQL\u8bc4\u4f30\u4f7f\u7528\u7d22\u5f15\u6bd4\u5168\u8868\u626b\u63cf\u66f4\u6162\uff0c\u5219\u4e0d\u4f1a\u4f7f\u7528\u7d22\u5f15\u3002\n\u5728rows\u4e00\u680f\u91cc\uff0c\u5982\u679c\u8fd4\u56de\u7684\u7ed3\u679c\u9884\u4f30\u4e3a\u4e00\u5f20\u8868\u7684\u5927\u90e8\u5206\uff0c\u7d22\u5f15\u626b\u63cf\u52a0\u4e0a\u968f\u673a\u78c1\u76d8\u8bbf\u95ee\u7684\u4ee3\u4ef7\u6bd4\u987a\u5e8f\u8bfb\u53d6\u6574\u5f20\u8868\u7684\u4ee3\u4ef7\u8981\u9ad8\uff0c\u4f18\u5316\u5668\u5c31\u4f1a\u6267\u884c\u5168\u8868\u626b\u63cf\uff0c\u5c31\u4f1a\u51fa\u73b0\u7d22\u5f15\u5931\u6548\u7684\u60c5\u51b5\u3002<\/p>\n\n\n\n
MySQL\u4f7f\u7528\u57fa\u4e8e\u6210\u672c\u7684\u4f18\u5316\u5668\uff0c\u5b83\u4f1a\u9884\u6d4b\u4e00\u4e2a\u67e5\u8be2\u4f7f\u7528\u67d0\u79cd\u6267\u884c\u8ba1\u5212\u65f6\u7684\u6210\u672c\uff0c\u5e76\u9009\u62e9\u5176\u4e2d\u6210\u672c\u6700\u5c0f\u7684\u4e00\u4e2a\u3002\n\u4f18\u5316\u5668\u5728\u8bc4\u4f30\u6210\u672c\u7684\u65f6\u5019\u5e76\u4e0d\u8003\u8651\u4efb\u4f55\u5c42\u9762\u7684\u7f13\u5b58\uff0c\u5b83\u5047\u8bbe\u8bfb\u53d6\u4efb\u4f55\u6570\u636e\u90fd\u9700\u8981\u4e00\u6b21\u78c1\u76d8I\/O\nMySQL\u4f9d\u8d56\u5b58\u50a8\u5f15\u64ce\u63d0\u4f9b\u7684\u7edf\u8ba1\u4fe1\u606f\u6765\u8bc4\u4f30\u6210\u672c\uff0c\u800cInnoDB\u56e0\u4e3a\u5176MVCC\u7684\u67b6\u6784\uff0c\u5e76\u4e0d\u80fd\u7ef4\u62a4\u4e00\u4e2a\u6570\u636e\u8868\u884c\u6570\u7684\u7cbe\u786e\u7edf\u8ba1\u4fe1\u606f\u3002\n\u6240\u4ee5MySQL\u7684\u6700\u4f18\u4e0d\u4e00\u5b9a\u662f\u6700\u7406\u6027\u7684\u6700\u4f18\u60c5\u51b5\u3002\n---\u300a\u9ad8\u6027\u80fdMySQL\uff08\u7b2c3\u7248\uff09\u300b 6.4.3\u67e5\u8be2\u4f18\u5316\u5904\u7406\n<\/code><\/pre>\n\n\n\n
SQL\u63d0\u793a\uff1a<\/h3>\n\n\n\n
\u5982\u679c\u6709\u591a\u4e2a\u7d22\u5f15\uff0cMySQL\u5728\u9ed8\u8ba4\u60c5\u51b5\u4e0b\u4f1a\u7528\u4f18\u5316\u5668\u9009\u62e9\u4e00\u4e2a\u7d22\u5f15\u4f7f\u7528\u3002\n\u901a\u8fc7\u5728SQL\u8bed\u53e5\u4e2d\u52a0\u5165\u4e00\u4e9b\u4eba\u4e3a\u7684\u63d0\u793a\uff0c\u6765\u6307\u5b9a\u7d22\u5f15\u7684\u4f7f\u7528\u548c\u5ffd\u89c6\u3002<\/p>\n\n\n\n
SQL\u63d0\u793a\uff0c\u662f\u4f18\u5316\u6570\u636e\u5e93\u7684\u4e00\u4e2a\u91cd\u8981\u624b\u6bb5\u3002<\/p>\n\n\n\n
\u5206\u4e3a\u4f7f\u7528\u7d22\u5f15\uff0c\u5ffd\u89c6\u7d22\u5f15\u548c\u5f3a\u5236\u4f7f\u7528\u7d22\u5f15\n\u5728\u8868\u540d\u540e\u9762\u6dfb\u52a0\u76f8\u5173\u7684\u8bed\u53e5\u3002<\/p>\n\n\n\n
use index: \/\/ \u52a0\u5165\u7d22\u5f15\uff08MySQL\u53ef\u80fd\u4e0d\u7528\uff09\nselect * from t1 use index(index) where ...;\n\nignore index: \/\/ \u5ffd\u7565\u7d22\u5f15\nselect * from t1 ignore index(index) where ...;\n\nforce index: \/\/ \u5f3a\u5236\u4f7f\u7528\u7d22\u5f15\nselect * from t1 force index(index) where ...;\n<\/code><\/pre>\n\n\n\n
\u7d22\u5f15\u8bbe\u8ba1\u539f\u5219\uff1a<\/h3>\n\n\n\n
\"image-20240905174957302\"\/<\/div><\/figure>\n\n\n\n
<\/p>\n\n\n\n
\u603b\u7ed3\uff1a<\/h2>\n\n\n\n
\u7d22\u5f15\u662f\u4e00\u79cd\u6570\u636e\u7ed3\u6784\uff0c\u7528\u4ee5\u9ad8\u6548\u83b7\u53d6\u6570\u636e\n\u5e38\u7528\u7684\u7d22\u5f15\u7ed3\u6784\u662f B+\u6811\u548cHash B+\u6811\u9002\u5408\u6570\u636e\u7684\u6301\u4e45\u5316\uff0cHash\u9002\u5408\u5feb\u901f\u5339\u914d\u3002<\/p>\n\n\n\n
\u7d22\u5f15\u7684\u7c7b\u522b\uff1a\n    \u4e3b\u952e\u7d22\u5f15\u3001\u552f\u4e00\u7d22\u5f15\u3001\u5e38\u89c4\u7d22\u5f15\u3001\u5168\u6587\u7d22\u5f15\n    \u805a\u96c6\u7d22\u5f15\u3001\u4e8c\u7ea7\u7d22\u5f15<\/p>\n\n\n\n
\u7d22\u5f15\u8bed\u6cd5\uff1a<\/p>\n\n\n\n
\u200b    create [unique|fulltext] INDEX index_name ON [table_name] (col_name…);\n\u200b    show index from [table_name];\n\u200b    drop index [index_name] on [table_name];<\/p>\n\n\n\n
SQL\u6027\u80fd\u5206\u6790\uff1a\n    \u6267\u884c\u9891\u6b21 \n    \u6162\u67e5\u8be2\u65e5\u5fd7\n    profile\n    explain\n\u5176\u4e2d\u6700\u5e38\u7528\u7684\u662fexplain<\/p>\n\n\n\n
\u7d22\u5f15\u4f7f\u7528\uff1a\n    \u8054\u5408\u7d22\u5f15\n    \u7d22\u5f15\u5931\u6548\uff08\u51fd\u6570\u8fd0\u7b97\u3001\u5b57\u7b26\u4e32\u8f6c\u6362\u3001\u5c3e\u90e8\u6a21\u7cca\u5339\u914d\u3001OR\u7d22\u5f15\uff09\n    SQL\u63d0\u793a\n    \u8986\u76d6\u7d22\u5f15\uff08\u4e00\u79cd\u521b\u5efa\u7d22\u5f15\u7684\u601d\u60f3\uff0c\u907f\u514d\u56de\u8868\u67e5\u8be2\uff09\n    \u524d\u7f00\u7d22\u5f15\n    \u5355\u5217\/\u8054\u5408\u7d22\u5f15<\/p>\n\n\n\n
\u7d22\u5f15\u8bbe\u8ba1\u539f\u5219\uff1a\n    \u5728\u54ea\u5efa\uff0c\u5efa\u7acb\u4ec0\u4e48\u7d22\u5f15\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u7b80\u4ecb\uff1a \u7d22\u5f15\uff08index\uff09\u662f\u5e2e\u52a9MySQL\u9ad8\u6548\u83b7\u53d6\u6570\u636e\u7684\u6570\u636e\u7ed3\u6784\uff08\u6709\u5e8f\uff09 \u5168\u8868\u626b\u63cf\u6027\u80fd\u6781\u4f4e\u3002 \u5efa\u7acb\u7d22\u5f15\uff0c\u5c31\u662f\u5efa […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","footnotes":""},"categories":[1],"tags":[],"class_list":["post-495","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/forelink.top\/index.php\/wp-json\/wp\/v2\/posts\/495","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/forelink.top\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/forelink.top\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/forelink.top\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/forelink.top\/index.php\/wp-json\/wp\/v2\/comments?post=495"}],"version-history":[{"count":3,"href":"https:\/\/forelink.top\/index.php\/wp-json\/wp\/v2\/posts\/495\/revisions"}],"predecessor-version":[{"id":500,"href":"https:\/\/forelink.top\/index.php\/wp-json\/wp\/v2\/posts\/495\/revisions\/500"}],"wp:attachment":[{"href":"https:\/\/forelink.top\/index.php\/wp-json\/wp\/v2\/media?parent=495"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/forelink.top\/index.php\/wp-json\/wp\/v2\/categories?post=495"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/forelink.top\/index.php\/wp-json\/wp\/v2\/tags?post=495"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}