{"id":20666,"date":"2026-04-18T19:07:39","date_gmt":"2026-04-18T11:07:39","guid":{"rendered":"https:\/\/92it.top\/?p=20666"},"modified":"2026-04-18T19:07:39","modified_gmt":"2026-04-18T11:07:39","slug":"90-%e7%9a%84%e6%85%a2-sql%ef%bc%8c%e9%83%bd%e4%b8%8d%e6%98%af%e5%9b%a0%e4%b8%ba%e6%95%b0%e6%8d%ae%e9%87%8f%e5%a4%a7","status":"publish","type":"post","link":"https:\/\/92it.top\/?p=20666","title":{"rendered":"90% \u7684\u6162 SQL\uff0c\u90fd\u4e0d\u662f\u56e0\u4e3a\u6570\u636e\u91cf\u5927"},"content":{"rendered":"\n

\u8f6c\u8f7d\uff1a90% \u7684\u6162 SQL\uff0c\u90fd\u4e0d\u662f\u56e0\u4e3a\u6570\u636e\u91cf\u5927<\/a><\/p>\n\n\n\n

\u524d\u8a00\ud83d\udd16<\/strong><\/p>\n\n\n\n

\n\n\n\n

\u5f88\u591a\u4eba\u4e00\u770b\u5230 SQL \u8dd1\u5f97\u6162\uff0c\u7b2c\u4e00\u53cd\u5e94\u5c31\u662f\uff1a\u6570\u636e\u91cf\u592a\u5927\u4e86\u3002<\/strong><\/p>\n\n\n\n

\u8fd9\u8bdd\u6709\u65f6\u5019\u6ca1\u9519\uff0c\u4f46\u66f4\u591a\u65f6\u5019\uff0c\u5b83\u53ea\u662f\u4e2a\u770b\u8d77\u6765\u5f88\u5408\u7406\u7684\u501f\u53e3\u3002<\/p>\n\n\n\n

\u771f\u5b9e\u60c5\u51b5\u5f80\u5f80\u66f4\u624e\u5fc3\uff1a \u8868\u4e0d\u7b97\u5927\uff0c\u673a\u5668\u4e5f\u8fd8\u884c\uff0c\u7d22\u5f15\u751a\u81f3\u90fd\u5efa\u4e86\uff0cSQL \u8fd8\u662f\u6162\u3002<\/strong>
\u90a3\u95ee\u9898\u591a\u534a\u4e0d\u5728\u201c\u6570\u636e\u91cf\u201d\uff0c\u800c\u5728 SQL \u5199\u6cd5\u628a\u6570\u636e\u5e93\u4f18\u5316\u5668\u6574\u4e0d\u4f1a\u4e86<\/strong>\u3002<\/p>\n\n\n\n

\u8bf4\u5f97\u66f4\u76f4\u63a5\u4e00\u70b9\uff1a \u6162 SQL\uff0c\u5927\u591a\u6570\u4e0d\u662f\u201c\u625b\u4e0d\u4f4f\u201d\uff0c\u800c\u662f\u201c\u5199\u5f97\u70c2\u201d\u3002<\/strong><\/p>\n\n\n\n

\u4eca\u5929\u8fd9\u7bc7\uff0c\u5c31\u804a\u51e0\u4e2a\u6700\u5e38\u89c1\u3001\u6700\u6709\u4ee3\u8868\u6027\u7684\u5751\u3002\u4f60\u4f1a\u53d1\u73b0\uff0c\u5f88\u591a\u6027\u80fd\u95ee\u9898\uff0c\u6839\u672c\u4e0d\u662f\u5347\u7ea7\u673a\u5668\u80fd\u89e3\u51b3\u7684\u3002<\/p>\n\n\n\n

\u3000\u3000<\/p>\n\n\n\n

\u4e00\u3001\u4e0d\u662f\u6570\u636e\u91cf\u5927\uff0c\u800c\u662f\u4f60\u5148\u8ba9\u7d22\u5f15\u5931\u6548\u4e86\ud83d\udd16<\/strong><\/p>\n\n\n\n

\n\n\n\n

\u6570\u636e\u5e93\u6027\u80fd\u4f18\u5316\u91cc\uff0c\u7d22\u5f15\u50cf\u9ad8\u901f\u516c\u8def\u3002
\u4f60\u660e\u660e\u4fee\u4e86\u8def\uff0c\u7ed3\u679c SQL \u4e00\u5199\uff0c\u81ea\u5df1\u5148\u628a\u8def\u5c01\u4e86\uff0c\u7136\u540e\u8fd8\u602a\u8f66\u591a\u3002<\/p>\n\n\n\n

\u6700\u5178\u578b\u7684\u51e0\u79cd\u5199\u6cd5\uff1a<\/p>\n\n\n\n

\ud83d\udd391. \u5bf9\u7d22\u5f15\u5217\u505a\u51fd\u6570\u8ba1\u7b97<\/strong><\/p>\n\n\n\n

\u6bd4\u5982\uff1a<\/p>\n\n\n\n

SELECT *\nFROM orders\nWHERE DATE(create_time) = '2026-03-01';<\/pre>\n\n\n\n
\u5982\u679c create_time<\/code> \u4e0a\u6709\u7d22\u5f15\uff0c\u5f88\u591a\u4eba\u4ee5\u4e3a\u8fd9\u6761\u8bed\u53e5\u4f1a\u8d70\u7d22\u5f15\u3002
\u4f46\u73b0\u5b9e\u901a\u5e38\u662f\uff1a\u4e0d\u4f1a\u3002<\/strong><\/p>\n\n\n\n
\u56e0\u4e3a\u4f60\u5bf9\u5217\u505a\u4e86 DATE()<\/code> \u8fd0\u7b97\uff0c\u6570\u636e\u5e93\u6ca1\u6cd5\u76f4\u63a5\u5229\u7528\u539f\u59cb\u7d22\u5f15\u503c\uff0c\u53ea\u80fd\u8001\u8001\u5b9e\u5b9e\u626b\u5927\u91cf\u6570\u636e\u518d\u8ba1\u7b97\u3002<\/p>\n\n\n\n
\u66f4\u597d\u7684\u5199\u6cd5\uff1a<\/p>\n\n\n\n
SELECT *\nFROM orders\nWHERE create_time >= '2026-03-01 00:00:00';\n  AND create_time < '2026-03-02 00:00:00';<\/pre>\n\n\n\n
\u8fd9\u7c7b\u8303\u56f4\u67e5\u8be2\uff0c\u624d\u66f4\u5bb9\u6613\u771f\u6b63\u5229\u7528\u7d22\u5f15\u3002<\/p>\n\n\n\n
\u3000\u3000<\/p>\n\n\n\n
\ud83d\udd392. \u9690\u5f0f\u7c7b\u578b\u8f6c\u6362<\/strong><\/p>\n\n\n\n
\u6bd4\u5982\u624b\u673a\u53f7\u662f\u5b57\u7b26\u4e32\u7c7b\u578b\uff0c\u4f60\u5374\u62ff\u6570\u5b57\u53bb\u67e5\uff1a<\/p>\n\n\n\n
SELECT *\nFROM user_profile\nWHERE phone = '13800138000';<\/pre>\n\n\n\n
\u770b\u8d77\u6765\u53ea\u662f\u5c11\u6253\u4e86\u4e24\u4e2a\u5f15\u53f7\uff0c\u5b9e\u9645\u4e0a\u6570\u636e\u5e93\u53ef\u80fd\u8981\u505a\u7c7b\u578b\u8f6c\u6362\u3002
\u4e00\u65e6\u8f6c\u6362\u65b9\u5411\u4e0d\u53cb\u597d\uff0c\u7d22\u5f15\u5229\u7528\u7387\u5c31\u4f1a\u76f4\u63a5\u6389\u4e0b\u53bb\u3002<\/p>\n\n\n\n
\u522b\u5c0f\u770b\u8fd9\u79cd\u4f4e\u7ea7\u9519\u8bef\u3002<\/strong>
\u7ebf\u4e0a\u5f88\u591a\u201c\u5076\u53d1\u6027\u6162 SQL\u201d\uff0c\u672c\u8d28\u5c31\u662f\u8fd9\u79cd\u4ee3\u7801\u7ec6\u8282\u5bfc\u81f4\u7684\u3002<\/p>\n\n\n\n
\u3000\u3000<\/p>\n\n\n\n
\ud83d\udd393. \u524d\u5bfc\u6a21\u7cca\u5339\u914d<\/strong><\/p>\n\n\n\n
SELECT *\nFROM product\nWHERE product_name LIKE '%\u5496\u5561';<\/pre>\n\n\n\n
LIKE '%xxx'<\/code> \u8fd9\u79cd\u524d\u9762\u5e26 %<\/code> \u7684\u5199\u6cd5\uff0cB+ \u6811\u7d22\u5f15\u57fa\u672c\u5e2e\u4e0d\u4e0a\u5fd9\u3002
\u56e0\u4e3a\u5b83\u65e0\u6cd5\u4ece\u6709\u5e8f\u524d\u7f00\u5f00\u59cb\u5b9a\u4f4d\uff0c\u53ea\u80fd\u9760\u626b\u63cf\u3002<\/p>\n\n\n\n
\u5982\u679c\u4f60\u7684\u4e1a\u52a1\u91cc\u8fd9\u79cd\u67e5\u8be2\u975e\u5e38\u5e38\u89c1\uff0c\u90a3\u5c31\u522b\u786c\u62ff\u666e\u901a\u7d22\u5f15\u625b\uff1a<\/p>\n\n\n\n
    \n
  • \u2022 \u8981\u4e48\u6539\u4e1a\u52a1\u68c0\u7d22\u65b9\u5f0f<\/li>\n\n\n\n
  • \u2022 \u8981\u4e48\u4e0a\u5012\u6392\u7d22\u5f15 \/ \u5168\u6587\u68c0\u7d22<\/li>\n\n\n\n
  • \u2022 \u8981\u4e48\u5355\u72ec\u8bbe\u8ba1\u641c\u7d22\u670d\u52a1<\/li>\n<\/ul>\n\n\n\n
    \u522b\u62ff\u6570\u636e\u5e93\u5f53\u641c\u7d22\u5f15\u64ce\uff0c\u8fd8\u602a\u5b83\u4e0d\u591f\u5feb\u3002<\/p>\n\n\n\n
    \u3000\u3000<\/p>\n\n\n\n
    \u4e8c\u3001\u4e0d\u662f\u6570\u636e\u591a\uff0c\u800c\u662f\u4f60\u67e5\u4e86\u592a\u591a\u6ca1\u7528\u7684\u6570\u636e\ud83d\udd16<\/strong><\/p>\n\n\n\n
    \n\n\n\n
    \u5f88\u591a SQL \u6162\uff0c\u95ee\u9898\u751a\u81f3\u4e0d\u5728\u6761\u4ef6\uff0c\u800c\u5728\u00a0\u4f60\u62ff\u592a\u591a\u4e86<\/strong>\u3002<\/p>\n\n\n\n
    \ud83d\udd39\u00a01.\u00a0SELECT *<\/code>\u00a0\u662f\u6027\u80fd\u61d2\u764c<\/strong><\/p>\n\n\n\n
    SELECT *\nFROM orders\nWHERE user_id = 1001;<\/pre>\n\n\n\n
    \u8fd9\u53e5\u5199\u8d77\u6765\u6700\u7701\u4e8b\uff0c\u540e\u679c\u901a\u5e38\u6700\u4e0d\u7701\u4e8b\u3002<\/p>\n\n\n\n
    \u4e3a\u4ec0\u4e48\uff1f<\/p>\n\n\n\n
      \n
    • \u8bfb\u53d6\u4e86\u6839\u672c\u7528\u4e0d\u5230\u7684\u5217<\/li>\n\n\n\n
    • \u589e\u52a0\u4e86\u78c1\u76d8 IO<\/li>\n\n\n\n
    • \u589e\u52a0\u4e86\u7f51\u7edc\u4f20\u8f93<\/li>\n\n\n\n
    • \u53ef\u80fd\u8ba9\u8986\u76d6\u7d22\u5f15\u5931\u6548<\/li>\n<\/ul>\n\n\n\n
      \u5982\u679c\u4f60\u771f\u6b63\u53ea\u9700\u8981\uff1a<\/p>\n\n\n\n
      SELECT order_id, amount, status\nFROM orders\nWHERE user_id = 1001;<\/pre>\n\n\n\n
      \u90a3\u5c31\u8001\u8001\u5b9e\u5b9e\u53ea\u67e5\u8fd9\u4e09\u5217\u3002<\/p>\n\n\n\n
      \u5f88\u591a\u573a\u666f\u4e0b\uff0c\u5b57\u6bb5\u4e00\u6536\u7a84\uff0c\u6027\u80fd\u5c31\u8089\u773c\u53ef\u89c1\u5730\u597d\u8d77\u6765\u3002<\/strong><\/p>\n\n\n\n
      \u3000\u3000<\/p>\n\n\n\n
      \ud83d\udd39\u00a02. \u6ca1\u6709\u9650\u5236\u8fd4\u56de\u884c\u6570<\/strong><\/p>\n\n\n\n
      \u6709\u4e9b\u63a5\u53e3\u660e\u660e\u524d\u7aef\u53ea\u5c55\u793a 20 \u6761\uff0c\u4f60\u540e\u7aef SQL \u5374\u5148\u635e 5 \u4e07\u6761\u56de\u6765\uff0c\u518d\u5728\u4ee3\u7801\u91cc\u6162\u6162\u5904\u7406\u3002<\/p>\n\n\n\n
      \u8fd9\u4e0d\u662f\u6570\u636e\u5e93\u6162\uff0c\u8fd9\u662f\u4f60\u5bf9\u6570\u636e\u5e93\u4e0d\u592a\u5ba2\u6c14\u3002<\/p>\n\n\n\n
      \u8be5\u52a0\u00a0LIMIT<\/code>\u00a0\u7684\u5730\u65b9\u5c31\u52a0\uff0c
      \u8be5\u505a\u5206\u9875\u7684\u5730\u65b9\u5c31\u5206\u9875\uff0c
      \u8be5\u505a\u6e38\u6807\u7ffb\u9875\u7684\u5730\u65b9\u522b\u786c\u4e0a\u6df1\u5206\u9875\u3002<\/p>\n\n\n\n
      \u3000\u3000<\/p>\n\n\n\n
      \u4e09\u3001\u4e0d\u662f\u6570\u636e\u91cf\u95ee\u9898\uff0c\u800c\u662f JOIN \/ \u5b50\u67e5\u8be2\u5199\u5f97\u592a\u4efb\u6027\ud83d\udd16<\/strong><\/p>\n\n\n\n
      \n\n\n\n
      SQL \u6162\uff0c\u4e0d\u5c11\u65f6\u5019\u6162\u5728\u201c\u5173\u7cfb\u592a\u590d\u6742\u201d\uff0c\u4e0d\u662f\u201c\u6570\u636e\u592a\u5927\u201d\u3002<\/p>\n\n\n\n
      \ud83d\udd391. \u5c0f\u8868\u9a71\u52a8\u5927\u8868\uff0c\u4e0d\u662f\u7384\u5b66\uff0c\u662f\u5e38\u8bc6<\/strong><\/p>\n\n\n\n
      \u5982\u679c\u591a\u8868\u5173\u8054\u65f6\uff0c\u8fc7\u6ee4\u6761\u4ef6\u6ca1\u6709\u5c3d\u65e9\u751f\u6548\uff0c\u6570\u636e\u5e93\u53ef\u80fd\u4f1a\u5148\u751f\u6210\u5f88\u5927\u7684\u4e2d\u95f4\u7ed3\u679c\u96c6\uff0c\u518d\u4e00\u6b65\u6b65\u7b5b\u3002<\/p>\n\n\n\n
      \u8fd9\u5c31\u50cf\u4f60\u5148\u628a\u5168\u516c\u53f8\u7684\u4eba\u90fd\u62c9\u8fdb\u4f1a\u8bae\u5ba4\uff0c\u518d\u95ee\u4e00\u53e5\u201c\u505a\u540e\u7aef\u7684\u7559\u4e0b\u201d\u3002<\/p>\n\n\n\n
      \u4e0d\u6162\u624d\u602a\u3002<\/p>\n\n\n\n
      \u4f18\u5316\u601d\u8def\u901a\u5e38\u5305\u62ec\uff1a<\/p>\n\n\n\n
        \n
      • \u5148\u8fc7\u6ee4\u518d\u5173\u8054<\/li>\n\n\n\n
      • \u7ed9\u5173\u8054\u5217\u52a0\u5408\u9002\u7d22\u5f15<\/li>\n\n\n\n
      • \u907f\u514d\u65e0\u8c13\u7684\u5bbd\u8868 JOIN<\/li>\n\n\n\n
      • \u770b\u6267\u884c\u8ba1\u5212\uff0c\u786e\u8ba4\u9a71\u52a8\u8868\u662f\u5426\u5408\u7406<\/li>\n<\/ul>\n\n\n\n
        \u3000\u3000<\/p>\n\n\n\n
        \ud83d\udd392. \u5b50\u67e5\u8be2\u4e0d\u662f\u539f\u7f6a\uff0c\u4f46\u4e71\u5199\u4f1a\u51fa\u4e8b<\/strong><\/p>\n\n\n\n
        \u6bd4\u5982\u76f8\u5173\u5b50\u67e5\u8be2\uff1a<\/p>\n\n\n\n
        SELECT u.id,\n       (SELECT COUNT(*) FROM orders o WHERE o.user_id = u.id) AS order_cnt\nFROM users u;<\/pre>\n\n\n\n
        \u5982\u679c\u5916\u5c42 users<\/code> \u8bb0\u5f55\u5f88\u591a\uff0c\u5185\u5c42\u5b50\u67e5\u8be2\u53ef\u80fd\u88ab\u53cd\u590d\u6267\u884c\u3002<\/p>\n\n\n\n
        \u5728\u4e00\u4e9b\u573a\u666f\u4e0b\uff0c\u6539\u6210\u805a\u5408\u540e\u518d JOIN\uff0c\u6027\u80fd\u4f1a\u7a33\u5b9a\u5f88\u591a\uff1a<\/p>\n\n\n\n
        SELECT u.id, t.order_cnt\nFROM users u\nLEFT JOIN (\n    SELECT user_id, COUNT(*) AS order_cnt\n    FROM orders\n    GROUP BY user_id\n) t ON u.id = t.user_id;<\/pre>\n\n\n\n
        \u5f53\u7136\uff0c\u5177\u4f53\u8fd8\u8981\u770b\u6570\u636e\u5e93\u7248\u672c\u3001\u4f18\u5316\u5668\u80fd\u529b\u548c\u5b9e\u9645\u6267\u884c\u8ba1\u5212\u3002
        \u4f46\u6709\u4e00\u70b9\u4e0d\u4f1a\u53d8\uff1a\u00a0\u522b\u53ea\u770b SQL \u80fd\u4e0d\u80fd\u8dd1\uff0c\u8981\u770b\u5b83\u5230\u5e95\u600e\u4e48\u8dd1\u3002<\/strong><\/p>\n\n\n\n
        \u3000\u3000<\/p>\n\n\n\n
        \u56db\u3001\u4e0d\u662f\u8868\u592a\u5927\uff0c\u800c\u662f\u6392\u5e8f\u3001\u5206\u7ec4\u6ca1\u501f\u4e0a\u7d22\u5f15\u7684\u529b\ud83d\udd16<\/strong><\/p>\n\n\n\n
        \n\n\n\n
        \ud83d\udd391.\u00a0ORDER BY<\/code>\u00a0\u4e00\u65e6\u6392\u4e0d\u52a8\uff0c\u5c31\u5f00\u59cb\u6d88\u8017\u5185\u5b58\u548c\u78c1\u76d8<\/strong><\/p>\n\n\n\n
        SELECT id, user_id, create_time\nFROM orders\nWHERE status = 'paid';\nORDER BY create_time DESC;<\/pre>\n\n\n\n
        \u5982\u679c status<\/code>\u3001create_time<\/code> \u4e0a\u6ca1\u6709\u5f62\u6210\u5408\u9002\u7684\u8054\u5408\u7d22\u5f15\uff0c\u6570\u636e\u5e93\u5c31\u53ef\u80fd\u5148\u7b5b\u9009\uff0c\u518d\u505a\u989d\u5916\u6392\u5e8f\u3002<\/p>\n\n\n\n
        \u6570\u636e\u4e00\u591a\uff0c\u6392\u5e8f\u6210\u672c\u975e\u5e38\u9ad8\uff0c\u751a\u81f3\u4f1a\u4ea7\u751f\u4e34\u65f6\u6587\u4ef6\u3002<\/p>\n\n\n\n
        \u5f88\u591a\u4eba\u770b\u5230\u6162\uff0c\u5c31\u8bf4\u201c\u56e0\u4e3a\u8ba2\u5355\u8868\u592a\u5927\u201d\u3002
        \u5176\u5b9e\u66f4\u51c6\u786e\u7684\u8bf4\u6cd5\u662f\uff1a\u00a0\u4f60\u60f3\u6392\u5e8f\uff0c\u4f46\u6ca1\u7ed9\u6570\u636e\u5e93\u4e00\u6761\u80fd\u987a\u7740\u8d70\u7684\u8def\u3002<\/strong><\/p>\n\n\n\n
        \u3000\u3000<\/p>\n\n\n\n
        \ud83d\udd392.\u00a0GROUP BY<\/code>\u00a0\u4e5f\u4e00\u6837<\/strong><\/p>\n\n\n\n
        \u5206\u7ec4\u7edf\u8ba1\u672c\u8eab\u5c31\u6709\u6210\u672c\u3002
        \u5982\u679c\u8fd8\u80fd\u987a\u7740\u7d22\u5f15\u5206\u7ec4\uff0c\u6210\u672c\u4f1a\u4f4e\u5f88\u591a\uff1b
        \u5982\u679c\u4e0d\u80fd\uff0c\u5c31\u5bb9\u6613\u51fa\u73b0\u4e34\u65f6\u8868\u3001\u989d\u5916\u6392\u5e8f\u3001CPU \u98d9\u9ad8\u3002<\/p>\n\n\n\n
        \u6240\u4ee5\u522b\u53ea\u76ef\u7740 where \u6761\u4ef6\u5efa\u7d22\u5f15\uff0c
        ORDER BY<\/code>\u3001GROUP BY<\/code>\u00a0\u7684\u5b57\u6bb5\u987a\u5e8f\uff0c\u4e5f\u5e38\u5e38\u51b3\u5b9a\u4e86\u8fd9\u6761 SQL \u7684\u751f\u6b7b\u3002<\/p>\n\n\n\n
        \u3000\u3000<\/p>\n\n\n\n
        \u4e94\u3001\u4e0d\u662f\u6570\u636e\u91cf\u5927\uff0c\u800c\u662f\u5206\u9875\u65b9\u5f0f\u9519\u4e86\ud83d\udd16<\/strong><\/p>\n\n\n\n
        \n\n\n\n
        \u5f88\u591a\u540e\u53f0\u7cfb\u7edf\u4e00\u4e0a\u6765\u5c31\u662f\u8fd9\u79cd\u5206\u9875\uff1a<\/p>\n\n\n\n
        SELECT *\nFROM orders\nORDER BY id\nLIMIT 100000, 20;<\/pre>\n\n\n\n
        \u8fd9\u7c7b\u6df1\u5206\u9875\uff0c\u9875\u6570\u8d8a\u5f80\u540e\u8d8a\u6162\u3002
        \u539f\u56e0\u4e0d\u662f\u6570\u636e\u5e93\u7a81\u7136\u53d8\u7b28\u4e86\uff0c\u800c\u662f\u5b83\u9700\u8981\u5148\u8df3\u8fc7\u524d\u9762\u5927\u91cf\u6570\u636e\uff0c\u518d\u62ff\u540e\u9762\u7684 20 \u6761\u3002<\/p>\n\n\n\n
        \u8fd9\u5c31\u50cf\u8ba9\u4eba\u4ece\u4e00\u672c 10 \u4e07\u9875\u7684\u4e66\u91cc\uff0c\u5148\u7ffb\u8fc7\u524d 99980 \u9875\uff0c\u518d\u7ed9\u4f60\u770b\u6700\u540e 20 \u9875\u3002<\/p>\n\n\n\n
        \u66f4\u7a33\u7684\u65b9\u5f0f\u901a\u5e38\u662f \u57fa\u4e8e\u6e38\u6807\u6216\u4e3b\u952e\u7ffb\u9875<\/strong>\uff1a<\/p>\n\n\n\n
        SELECT *\nFROM orders\nWHERE id > 100000\nORDER BY id\nLIMIT 20;<\/pre>\n\n\n\n
        \u5982\u679c\u4e1a\u52a1\u5141\u8bb8\uff0c\u8fd9\u79cd\u65b9\u5f0f\u901a\u5e38\u6bd4\u00a0LIMIT offset, size<\/code>\u00a0\u53ef\u9760\u5f97\u591a\u3002<\/p>\n\n\n\n
        \u3000\u3000<\/p>\n\n\n\n
        \u516d\u3001\u4e0d\u662f\u6570\u636e\u5e93\u4e0d\u884c\uff0c\u800c\u662f\u4f60\u6839\u672c\u6ca1\u770b\u6267\u884c\u8ba1\u5212\ud83d\udd16<\/strong><\/p>\n\n\n\n
        \n\n\n\n
        \u5f88\u591a\u6027\u80fd\u95ee\u9898\uff0c\u8ba8\u8bba\u534a\u5929\u90fd\u505c\u7559\u5728\u731c\u6d4b\u5c42\u9762\uff1a<\/p>\n\n\n\n
          \n
        • \u662f\u4e0d\u662f\u6570\u636e\u592a\u5927\uff1f<\/li>\n\n\n\n
        • \u662f\u4e0d\u662f\u6570\u636e\u5e93\u7248\u672c\u4e0d\u884c\uff1f<\/li>\n\n\n\n
        • \u662f\u4e0d\u662f\u673a\u5668\u914d\u7f6e\u4e0d\u591f\uff1f<\/li>\n\n\n\n
        • \u662f\u4e0d\u662f\u8be5\u5206\u5e93\u5206\u8868\u4e86\uff1f<\/li>\n<\/ul>\n\n\n\n
          \u7ed3\u679c\u4e00\u770b EXPLAIN<\/code>\uff0c\u53d1\u73b0\u538b\u6839\u6ca1\u8d70\u7d22\u5f15\u3002<\/p>\n\n\n\n
          \u8fd9\u5c31\u50cf\u75c5\u4eba\u54b3\u55fd\u4e24\u58f0\uff0c\u4f60\u76f4\u63a5\u63d0\u8bae\u6362\u5668\u5b98\u3002<\/p>\n\n\n\n
          \u5148\u770b\u8fd9\u51e0\u4e2a\u5173\u952e\u4fe1\u53f7\uff1a<\/p>\n\n\n\n
            \n
          • type<\/strong>\uff1a\u662f\u4e0d\u662f\u5168\u8868\u626b\u63cf<\/li>\n\n\n\n
          • key<\/strong>\uff1a\u5b9e\u9645\u7528\u4e86\u54ea\u4e2a\u7d22\u5f15<\/li>\n\n\n\n
          • rows<\/strong>\uff1a\u9884\u4f30\u626b\u63cf\u4e86\u591a\u5c11\u884c<\/li>\n\n\n\n
          • Extra<\/strong>\uff1a\u6709\u6ca1\u6709\u00a0Using filesort<\/code>\u3001Using temporary<\/code><\/li>\n<\/ul>\n\n\n\n
            \u5f88\u591a\u6240\u8c13\u7684\u5927\u95ee\u9898\uff0c\u6267\u884c\u8ba1\u5212\u4e00\u62c9\u51fa\u6765\uff0c\u5341\u5206\u949f\u5c31\u80fd\u5b9a\u4f4d\u3002<\/p>\n\n\n\n
            \u522b\u4e0a\u6765\u5c31\u8c08\u67b6\u6784\u5347\u7ea7\u3002
            \u5148\u770b\u770b\u662f\u4e0d\u662f\u4e00\u6761 SQL \u5199\u5f97\u4e0d\u592a\u50cf\u6837\u3002<\/p>\n\n\n\n
            \u3000\u3000<\/p>\n\n\n\n
            \u4e03\u3001\u4ec0\u4e48\u65f6\u5019\u201c\u6570\u636e\u91cf\u5927\u201d\u624d\u771f\u7684\u662f\u6838\u5fc3\u95ee\u9898\uff1f\ud83d\udd16<\/strong><\/p>\n\n\n\n
            \n\n\n\n
            \u8bf4\u4e86\u8fd9\u4e48\u591a\uff0c\u4e0d\u662f\u8981\u5426\u8ba4\u6570\u636e\u91cf\u7684\u5f71\u54cd\u3002<\/p>\n\n\n\n
            \u6570\u636e\u91cf\u5f53\u7136\u4f1a\u5e26\u6765\u6027\u80fd\u538b\u529b\uff0c\u5c24\u5176\u5728\u8fd9\u4e9b\u573a\u666f\u91cc\uff1a<\/p>\n\n\n\n
              \n
            • \u70ed\u6570\u636e\u975e\u5e38\u96c6\u4e2d<\/li>\n\n\n\n
            • \u5355\u8868\u8fbe\u5230\u5343\u4e07\u3001\u4e0a\u4ebf\u7ea7\u522b<\/li>\n\n\n\n
            • \u7edf\u8ba1\u5206\u6790\u578b\u67e5\u8be2\u5f88\u591a<\/li>\n\n\n\n
            • \u7d22\u5f15\u4f53\u79ef\u5de8\u5927\uff0c\u7f13\u5b58\u547d\u4e2d\u4e0b\u964d<\/li>\n\n\n\n
            • \u5199\u5165\u9891\u7e41\uff0c\u7d22\u5f15\u7ef4\u62a4\u6210\u672c\u9ad8<\/li>\n<\/ul>\n\n\n\n
              \u4f46\u91cd\u70b9\u662f\uff1a \u5f88\u591a\u56e2\u961f\u8fd8\u6ca1\u5230\u90a3\u4e2a\u91cf\u7ea7\uff0c\u5c31\u5df2\u7ecf\u5148\u628a SQL \u5199\u51fa\u4e86\u4ebf\u7ea7\u6570\u636e\u7684\u707e\u96be\u611f\u3002<\/strong><\/p>\n\n\n\n
              \u4e5f\u5c31\u662f\u8bf4\uff0c
              \u672c\u6765\u662f\u201c\u81ea\u884c\u8f66\u901a\u52e4\u201d\uff0c
              \u975e\u8981\u628a\u81ea\u5df1\u9a91\u51fa\u201c\u6a2a\u7a7f\u65e0\u4eba\u533a\u201d\u7684\u75db\u82e6\u4f53\u9a8c\u3002<\/p>\n\n\n\n
              \u3000\u3000<\/p>\n\n\n\n
              \u516b\u3001\u6392\u67e5\u6162 SQL\uff0c\u5efa\u8bae\u6309\u8fd9 5 \u6b65\u8d70\ud83d\udd16<\/strong><\/p>\n\n\n\n
              \n\n\n\n
              \u5982\u679c\u4f60\u60f3\u7cfb\u7edf\u4e00\u70b9\u6392\u67e5\uff0c\u5efa\u8bae\u6309\u8fd9\u4e2a\u987a\u5e8f\uff1a<\/p>\n\n\n\n
              \ud83d\udd391. \u5148\u770b\u6267\u884c\u8ba1\u5212<\/strong><\/p>\n\n\n\n
              \u4e0d\u8981\u731c\uff0c\u5148\u786e\u8ba4\u6709\u6ca1\u6709\u8d70\u7d22\u5f15\u3001\u626b\u63cf\u4e86\u591a\u5c11\u884c\u3001\u6709\u6ca1\u6709\u4e34\u65f6\u8868\u548c\u989d\u5916\u6392\u5e8f\u3002<\/p>\n\n\n\n
              \u3000\u3000<\/p>\n\n\n\n
              \ud83d\udd392. \u770b\u67e5\u8be2\u6761\u4ef6\u662f\u5426\u8ba9\u7d22\u5f15\u5931\u6548<\/strong><\/p>\n\n\n\n
              \u91cd\u70b9\u67e5\uff1a<\/p>\n\n\n\n
                \n
              • \u51fd\u6570\u64cd\u4f5c<\/li>\n\n\n\n
              • \u9690\u5f0f\u8f6c\u6362<\/li>\n\n\n\n
              • \u524d\u5bfc\u6a21\u7cca\u5339\u914d<\/li>\n\n\n\n
              • \u4e0d\u5408\u7406\u7684\u8054\u5408\u7d22\u5f15\u987a\u5e8f<\/li>\n<\/ul>\n\n\n\n
                \u3000\u3000<\/h3>\n\n\n\n
                \ud83d\udd393. \u770b\u662f\u4e0d\u662f\u67e5\u4e86\u592a\u591a\u5b57\u6bb5\u3001\u592a\u591a\u884c<\/strong><\/p>\n\n\n\n
                \u80fd\u4e0d\u80fd\u53bb\u6389\u00a0SELECT *<\/code>\uff1f
                \u80fd\u4e0d\u80fd\u7f29\u5c0f\u7ed3\u679c\u96c6\uff1f
                \u80fd\u4e0d\u80fd\u63d0\u524d\u8fc7\u6ee4\uff1f<\/p>\n\n\n\n
                \u3000\u3000<\/p>\n\n\n\n
                \ud83d\udd394. \u770b JOIN\u3001\u6392\u5e8f\u3001\u5206\u7ec4\u662f\u5426\u8bbe\u8ba1\u5408\u7406<\/strong><\/p>\n\n\n\n
                \u5f88\u591a SQL \u6162\uff0c\u4e0d\u5728 where\uff0c\u800c\u5728 join \/ order by \/ group by\u3002<\/p>\n\n\n\n
                \u3000\u3000<\/p>\n\n\n\n
                \ud83d\udd395. \u6700\u540e\u518d\u8003\u8651\u6570\u636e\u91cf\u548c\u67b6\u6784\u95ee\u9898<\/strong><\/p>\n\n\n\n
                \u5982\u679c SQL \u5199\u6cd5\u5df2\u7ecf\u6bd4\u8f83\u5065\u5eb7\uff0c\u7d22\u5f15\u4e5f\u5408\u7406\uff0c\u6267\u884c\u8ba1\u5212\u4e5f\u6ca1\u660e\u663e\u95ee\u9898\uff0c\u8fd9\u65f6\u5019\u518d\u8003\u8651\u5206\u5e93\u5206\u8868\u3001\u51b7\u70ed\u5206\u79bb\u3001\u7f13\u5b58\u3001\u641c\u7d22\u5f15\u64ce\u66ff\u4ee3\u7b49\u65b9\u6848\u3002<\/p>\n\n\n\n
                \u987a\u5e8f\u522b\u53cd\u4e86\u3002
                \u4e00\u4e0a\u6765\u5c31\u4e0a\u5927\u624b\u672f\uff0c\u901a\u5e38\u53ea\u662f\u628a\u4e00\u4e2a\u5c0f\u6bdb\u75c5\u5305\u88c5\u6210\u5927\u9879\u76ee\u3002<\/p>\n\n\n\n
                \u3000\u3000<\/p>\n\n\n\n
                \u7ed3\u8bed\ud83d\udd16<\/strong><\/p>\n\n\n\n
                \n\n\n\n
                \u6162 SQL \u8fd9\u4ef6\u4e8b\uff0c\u6700\u8bef\u5bfc\u4eba\u7684\u4e00\u53e5\u8bdd\u5c31\u662f\uff1a \u201c\u56e0\u4e3a\u6570\u636e\u91cf\u5927\u3002\u201d<\/strong><\/p>\n\n\n\n
                \u5b83\u542c\u8d77\u6765\u4e13\u4e1a\uff0c\u7529\u9505\u4e5f\u65b9\u4fbf\uff0c\u751a\u81f3\u8fd8\u80fd\u987a\u4fbf\u4e3a\u540e\u7eed\u4e70\u673a\u5668\u3001\u4e0a\u4e2d\u95f4\u4ef6\u3001\u505a\u590d\u6742\u67b6\u6784\u94fa\u57ab\u3002<\/p>\n\n\n\n
                \u4f46\u5f88\u591a\u65f6\u5019\uff0c\u771f\u76f8\u6ca1\u90a3\u4e48\u5b8f\u5927\u3002<\/p>\n\n\n\n
                \u771f\u76f8\u5f80\u5f80\u662f\uff1a<\/p>\n\n\n\n
                  \n
                • \u7d22\u5f15\u5931\u6548\u4e86<\/li>\n\n\n\n
                • \u67e5\u591a\u4e86<\/li>\n\n\n\n
                • \u6392\u5e8f\u65b9\u5f0f\u4e0d\u5bf9<\/li>\n\n\n\n
                • \u5206\u9875\u5199\u6cd5\u4e0d\u5bf9<\/li>\n\n\n\n
                • \u6267\u884c\u8ba1\u5212\u538b\u6839\u6ca1\u770b<\/li>\n<\/ul>\n\n\n\n
                  \u6240\u4ee5\uff0c\u4e0b\u6b21\u518d\u9047\u5230\u6162 SQL\uff0c\u5148\u522b\u6025\u7740\u602a\u6570\u636e\u91cf\u3002<\/p>\n\n\n\n
                  \u5148\u95ee\u4e00\u53e5\u66f4\u5b9e\u9645\u7684\u8bdd\uff1a \u8fd9\u6761 SQL\uff0c\u5230\u5e95\u662f\u4e0d\u662f\u201c\u50cf\u4e2a\u61c2\u4e8b\u7684 SQL\u201d\uff1f<\/strong><\/p>\n\n\n\n
                  \u8fd9\u4e2a\u95ee\u9898\uff0c\u901a\u5e38\u6bd4\u201c\u8868\u6709\u591a\u5927\u201d\u66f4\u63a5\u8fd1\u771f\u76f8\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
                  \u8f6c\u8f7d\uff1a90% \u7684\u6162 SQL\uff0c\u90fd\u4e0d\u662f\u56e0\u4e3a\u6570\u636e\u91cf\u5927 \u524d\u8a00\ud83d\udd16 \u5f88\u591a\u4eba\u4e00\u770b\u5230 SQL \u8dd1\u5f97\u6162\uff0c\u7b2c\u4e00\u53cd\u5e94\u5c31\u662f\uff1a\u6570\u636e\u91cf\u592a\u5927 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[],"_links":{"self":[{"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts\/20666"}],"collection":[{"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=20666"}],"version-history":[{"count":2,"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts\/20666\/revisions"}],"predecessor-version":[{"id":20668,"href":"https:\/\/92it.top\/index.php?rest_route=\/wp\/v2\/posts\/20666\/revisions\/20668"}],"wp:attachment":[{"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=20666"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=20666"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/92it.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=20666"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}