{"id":1601,"date":"2024-05-25T15:42:35","date_gmt":"2024-05-25T15:42:35","guid":{"rendered":"https:\/\/www.nicekj.com\/?p=1601"},"modified":"2024-05-25T15:42:35","modified_gmt":"2024-05-25T15:42:35","slug":"mysql-duobiaochaxunyudikaerjishenruxuexi","status":"publish","type":"post","link":"https:\/\/www.nicekj.com\/mysql-duobiaochaxunyudikaerjishenruxuexi.html","title":{"rendered":"\u3010MySQL\u3011 \u591a\u8868\u67e5\u8be2\u4e0e\u7b1b\u5361\u5c14\u79ef\u6df1\u5165\u5b66\u4e60"},"content":{"rendered":"
\n

\u63a8\u8350\u4e00\u6b3eAI\u7f51\u7ad9 AI\u5199\u4f5c\u4e0eAI\u7ed8\u753b\u667a\u80fd\u521b\u4f5c\u5e73\u53f0 – \u6d77\u9cb8AI | \u667a\u80fdAI\u52a9\u624b<\/a>\uff0c\u53ef\u4ee5\u514d\u8d39\u9886\u53d6GPT3.5\u65e0\u9650\u5361<\/code><\/p>\n<\/blockquote>\n

\u5728\u6570\u636e\u5e93\u64cd\u4f5c\u4e2d\uff0c\u591a\u8868\u67e5\u8be2\u662f\u4e00\u9879\u57fa\u7840\u800c\u91cd\u8981\u7684\u6280\u80fd\u3002\u5b83\u5141\u8bb8\u6211\u4eec\u4ece\u591a\u4e2a\u8868\u4e2d\u68c0\u7d22\u6570\u636e\uff0c\u4ee5\u4fbf\u8fdb\u884c\u590d\u6742\u7684\u6570\u636e\u5206\u6790\u548c\u62a5\u544a\u3002\u672c\u6587\u5c06\u6df1\u5165\u63a2\u8ba8MySQL\u4e2d\u7684\u591a\u8868\u67e5\u8be2\uff0c\u5305\u62ec\u4e0d\u540c\u7c7b\u578b\u7684\u8fde\u63a5\u67e5\u8be2\u3001\u5b50\u67e5\u8be2\uff0c\u4ee5\u53ca\u5982\u4f55\u907f\u514d\u7b1b\u5361\u5c14\u79ef\u7684\u4ea7\u751f\u3002<\/p>\n

\u591a\u8868\u67e5\u8be2\u5206\u7c7b<\/h2>\n

\u5728MySQL\u4e2d\uff0c\u591a\u8868\u67e5\u8be2\u4e3b\u8981\u5206\u4e3a\u4ee5\u4e0b\u51e0\u7c7b\uff1a<\/p>\n

    \n
  • \u8fde\u63a5\u67e5\u8be2\uff08JOIN\uff09<\/li>\n
  • \u5b50\u67e5\u8be2\uff08Subquery\uff09<\/li>\n<\/ul>\n

    \u8fde\u63a5\u67e5\u8be2<\/h2>\n

    \u8fde\u63a5\u67e5\u8be2\u662f\u6700\u5e38\u89c1\u7684\u591a\u8868\u67e5\u8be2\u65b9\u5f0f\uff0c\u5b83\u6839\u636e\u4e24\u4e2a\u6216\u591a\u4e2a\u8868\u4e2d\u7684\u5171\u540c\u5b57\u6bb5\u5c06\u5b83\u4eec\u8fde\u63a5\u8d77\u6765\u3002<\/p>\n

    \u5185\u8fde\u63a5\uff08INNER JOIN\uff09<\/h3>\n

    \u5185\u8fde\u63a5\u8fd4\u56de\u4e24\u4e2a\u8868\u4e2d\u5339\u914d\u7684\u8bb0\u5f55\u3002\u5982\u679c\u8868\u4e2d\u6709\u884c\u4e0d\u5339\u914d\uff0c\u5219\u4e0d\u4f1a\u8fd4\u56de\u8fd9\u4e9b\u884c\u3002<\/p>\n

    \u4f7f\u7528\u6848\u4f8b\uff1a<\/strong><\/p>\n

    \u5047\u8bbe\u6211\u4eec\u6709\u4e24\u4e2a\u8868\uff0cemployees<\/code> \u548c departments<\/code>\u3002<\/p>\n

    <\/div>
    sql<\/span>
    \u590d\u5236\u4ee3\u7801<\/div><\/div><\/div>SELECT<\/span> employees.name, departments.department_name<\/span>\nFROM<\/span> employees<\/span>\nINNER<\/span> JOIN<\/span> departments ON<\/span> employees.department_id =<\/span> departments.id;<\/span>\n<\/code><\/pre>\n
    \u8fd9\u6761\u67e5\u8be2\u5c06\u8fd4\u56de\u6240\u6709\u5458\u5de5\u53ca\u5176\u5bf9\u5e94\u7684\u90e8\u95e8\u540d\u79f0\u3002<\/p>\n
    \u5916\u8fde\u63a5\uff08OUTER JOIN\uff09<\/h3>\n
    \u5916\u8fde\u63a5\u5305\u62ec\u5de6\u5916\u8fde\u63a5\uff08LEFT JOIN\uff09\u3001\u53f3\u5916\u8fde\u63a5\uff08RIGHT JOIN\uff09\u548c\u5168\u5916\u8fde\u63a5\uff08FULL OUTER JOIN\uff0cMySQL\u4e0d\u76f4\u63a5\u652f\u6301\uff0c\u4f46\u53ef\u4ee5\u6a21\u62df\uff09\u3002<\/p>\n
    \u4f7f\u7528\u6848\u4f8b\uff1a<\/strong><\/p>\n
    <\/div>
    sql<\/span>
    \u590d\u5236\u4ee3\u7801<\/div><\/div><\/div>SELECT<\/span> employees.name, departments.department_name<\/span>\nFROM<\/span> employees<\/span>\nLEFT<\/span> JOIN<\/span> departments ON<\/span> employees.department_id =<\/span> departments.id;<\/span>\n<\/code><\/pre>\n
    \u8fd9\u6761\u67e5\u8be2\u5c06\u8fd4\u56de\u6240\u6709\u5458\u5de5\u7684\u540d\u5b57\uff0c\u5373\u4f7f\u4ed6\u4eec\u6ca1\u6709\u5bf9\u5e94\u7684\u90e8\u95e8\u3002<\/p>\n
    \u81ea\u8fde\u63a5\uff08SELF JOIN\uff09<\/h3>\n
    \u81ea\u8fde\u63a5\u662f\u6307\u8868\u4e0e\u81ea\u8eab\u8fdb\u884c\u8fde\u63a5\u3002\u8fd9\u5728\u5904\u7406\u5177\u6709\u5c42\u6b21\u7ed3\u6784\u6216\u6811\u5f62\u7ed3\u6784\u7684\u6570\u636e\u65f6\u975e\u5e38\u6709\u7528\u3002<\/p>\n
    \u4f7f\u7528\u6848\u4f8b\uff1a<\/strong><\/p>\n
    \u5047\u8bbeemployees<\/code>\u8868\u4e2d\u6709\u4e00\u4e2a\u5b57\u6bb5\u6307\u5411\u5458\u5de5\u7684\u7ecf\u7406\uff08manager_id\uff09\uff0c\u6211\u4eec\u53ef\u4ee5\u8fd9\u6837\u67e5\u8be2\u5458\u5de5\u53ca\u5176\u7ecf\u7406\u7684\u540d\u5b57\uff1a<\/p>\n
    <\/div>
    sql<\/span>
    \u590d\u5236\u4ee3\u7801<\/div><\/div><\/div>SELECT<\/span> e1.name AS<\/span> Employee, e2.name AS<\/span> Manager<\/span>\nFROM<\/span> employees e1<\/span>\nLEFT<\/span> JOIN<\/span> employees e2 ON<\/span> e1.manager_id =<\/span> e2.id;<\/span>\n<\/code><\/pre>\n
    \u5b50\u67e5\u8be2<\/h2>\n
    \u5b50\u67e5\u8be2\u662f\u5d4c\u5957\u5728\u5176\u4ed6\u67e5\u8be2\u4e2d\u7684\u67e5\u8be2\u3002\u5b83\u53ef\u4ee5\u7528\u5728SELECT\u3001INSERT\u3001UPDATE\u548cDELETE\u8bed\u53e5\u4e2d\uff0c\u4ee5\u53ca\u5728WHERE\u548cHAVING\u5b50\u53e5\u4e2d\u3002<\/p>\n
    \u4f7f\u7528\u6848\u4f8b\uff1a<\/strong><\/p>\n
    <\/div>
    sql<\/span>
    \u590d\u5236\u4ee3\u7801<\/div><\/div><\/div>SELECT<\/span> name<\/span>\nFROM<\/span> employees<\/span>\nWHERE<\/span> department_id IN<\/span> (SELECT<\/span> id FROM<\/span> departments WHERE<\/span> location =<\/span> 'New York'<\/span>);<\/span>\n<\/code><\/pre>\n
    \u8fd9\u6761\u67e5\u8be2\u5c06\u8fd4\u56de\u6240\u6709\u5728\u7ebd\u7ea6\u5de5\u4f5c\u7684\u5458\u5de5\u7684\u540d\u5b57\u3002<\/p>\n
    \u907f\u514d\u7b1b\u5361\u5c14\u79ef<\/h2>\n
    \u7b1b\u5361\u5c14\u79ef\u662f\u5728\u6ca1\u6709\u6307\u5b9a\u8fde\u63a5\u6761\u4ef6\u65f6\uff0c\u4e24\u4e2a\u8868\u7684\u6bcf\u4e00\u884c\u4e0e\u53e6\u4e00\u4e2a\u8868\u7684\u6bcf\u4e00\u884c\u76f8\u7ed3\u5408\uff0c\u5bfc\u81f4\u5927\u91cf\u65e0\u7528\u6570\u636e\u7684\u4ea7\u751f\u3002<\/p>\n
    \u5982\u4f55\u907f\u514d\uff1a<\/strong><\/p>\n
    \u603b\u662f\u786e\u4fdd\u5728\u8fdb\u884c\u8fde\u63a5\u67e5\u8be2\u65f6\u6307\u5b9a\u660e\u786e\u7684\u8fde\u63a5\u6761\u4ef6\u3002<\/p>\n
    <\/div>
    sql<\/span>
    \u590d\u5236\u4ee3\u7801<\/div><\/div><\/div>SELECT<\/span> *<\/span> FROM<\/span> employees, departments; -- \u9519\u8bef\u7684\u505a\u6cd5\uff0c\u4f1a\u4ea7\u751f\u7b1b\u5361\u5c14\u79ef<\/span><\/span>\n<\/span>\nSELECT<\/span> *<\/span> FROM<\/span> employees<\/span>\nJOIN<\/span> departments ON<\/span> employees.department_id =<\/span> departments.id; -- \u6b63\u786e\u7684\u505a\u6cd5<\/span><\/span>\n<\/code><\/pre>\n
    \u603b\u7ed3<\/h2>\n
    \u638c\u63e1\u591a\u8868\u67e5\u8be2\u5bf9\u4e8e\u8fdb\u884c\u590d\u6742\u7684\u6570\u636e\u5206\u6790\u81f3\u5173\u91cd\u8981\u3002\u901a\u8fc7\u5185\u8fde\u63a5\u3001\u5916\u8fde\u63a5\u548c\u81ea\u8fde\u63a5\uff0c\u6211\u4eec\u53ef\u4ee5\u7075\u6d3b\u5730\u4ece\u591a\u4e2a\u8868\u4e2d\u68c0\u7d22\u6570\u636e\u3002\u540c\u65f6\uff0c\u5b50\u67e5\u8be2\u63d0\u4f9b\u4e86\u4e00\u79cd\u5f3a\u5927\u7684\u5de5\u5177\u6765\u8fdb\u4e00\u6b65\u7ec6\u5316\u6211\u4eec\u7684\u6570\u636e\u68c0\u7d22\u3002\u52a1\u5fc5\u6ce8\u610f\u907f\u514d\u65e0\u610f\u4e2d\u4ea7\u751f\u7b1b\u5361\u5c14\u79ef\uff0c\u4ee5\u4fdd\u6301\u67e5\u8be2\u7684\u6548\u7387\u548c\u51c6\u786e\u6027\u3002\u901a\u8fc7\u5b9e\u9645\u6848\u4f8b\u7684\u7ec3\u4e60\uff0c\u4f60\u5c06\u80fd\u591f\u66f4\u597d\u5730\u7406\u89e3\u548c\u8fd0\u7528\u8fd9\u4e9b\u6982\u5ff5\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
    \u5728\u6570\u636e\u5e93\u64cd\u4f5c\u4e2d\uff0c\u591a\u8868\u67e5\u8be2\u662f\u4e00\u9879\u57fa\u7840\u800c\u91cd\u8981\u7684\u6280\u80fd\u3002\u5b83\u5141\u8bb8\u6211\u4eec\u4ece\u591a\u4e2a\u8868\u4e2d\u68c0\u7d22\u6570\u636e\uff0c\u4ee5\u4fbf\u8fdb\u884c\u590d\u6742\u7684\u6570\u636e\u5206\u6790\u548c\u62a5\u544a\u3002\u672c\u6587\u5c06\u6df1\u5165\u63a2\u8ba8MySQL\u4e2d\u7684\u591a\u8868\u67e5\u8be2\uff0c\u5305\u62ec\u4e0d\u540c\u7c7b\u578b\u7684\u8fde\u63a5\u67e5\u8be2\u3001\u5b50\u67e5\u8be2\uff0c\u4ee5\u53ca\u5982\u4f55\u907f\u514d\u7b1b\u5361\u5c14\u79ef\u7684<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"rank_math_title":"","rank_math_description":"","rank_math_focus_keyword":"","views":"2","footnotes":""},"categories":[3],"tags":[126,127,128,129,136],"collection":[],"class_list":["post-1601","post","type-post","status-publish","format-standard","hentry","category-fenlei2","tag-gpt","tag-ai","tag-128","tag-129","tag-136"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.nicekj.com\/nicekj2024\/wp\/v2\/posts\/1601","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.nicekj.com\/nicekj2024\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.nicekj.com\/nicekj2024\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.nicekj.com\/nicekj2024\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.nicekj.com\/nicekj2024\/wp\/v2\/comments?post=1601"}],"version-history":[{"count":0,"href":"https:\/\/www.nicekj.com\/nicekj2024\/wp\/v2\/posts\/1601\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.nicekj.com\/nicekj2024\/wp\/v2\/media?parent=1601"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.nicekj.com\/nicekj2024\/wp\/v2\/categories?post=1601"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.nicekj.com\/nicekj2024\/wp\/v2\/tags?post=1601"},{"taxonomy":"collection","embeddable":true,"href":"https:\/\/www.nicekj.com\/nicekj2024\/wp\/v2\/collection?post=1601"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}