{"id":199683,"date":"2025-05-06T08:50:53","date_gmt":"2025-05-06T00:50:53","guid":{"rendered":"https:\/\/server.hk\/cnblog\/199683\/"},"modified":"2025-05-06T08:50:53","modified_gmt":"2025-05-06T00:50:53","slug":"sql%e4%b8%adwhere%e5%ad%90%e5%8f%a5%e7%9a%84%e7%94%a8%e6%b3%95%e5%8f%8a%e7%a4%ba%e4%be%8b","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/199683\/","title":{"rendered":"SQL\u4e2dWHERE\u5b50\u53e5\u7684\u7528\u6cd5\u53ca\u793a\u4f8b"},"content":{"rendered":"

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

SQL\u4e2dWHERE\u5b50\u53e5\u7684\u7528\u6cd5\u53ca\u793a\u4f8b<\/h1>\n

\u4e0d\u77e5\u9053\u5927\u5bb6\u662f\u5426\u719f\u6089\uff1f\u4eca\u5929\u6211\u5c06\u7ed9\u5927\u5bb6\u4ecb\u7ecd\uff0c\u8fd9\u7bc7\u6587\u7ae0\u4e3b\u8981\u4f1a\u8bb2\u5230\u7b49\u7b49\u77e5\u8bc6\u70b9\uff0c\u5982\u679c\u4f60\u5728\u770b\u5b8c\u672c\u7bc7\u6587\u7ae0\u540e\uff0c\u6709\u66f4\u597d\u7684\u5efa\u8bae\u6216\u8005\u53d1\u73b0\u54ea\u91cc\u6709\u95ee\u9898\uff0c\u5e0c\u671b\u5927\u5bb6\u90fd\u80fd\u79ef\u6781\u8bc4\u8bba\u6307\u51fa\uff0c\u8c22\u8c22\uff01\u5e0c\u671b\u6211\u4eec\u80fd\u4e00\u8d77\u52a0\u6cb9\u8fdb\u6b65\uff01<\/p>\n

SQL\u4e2dWHERE\u7684\u7528\u6cd5\u6709\u54ea\u4e9b\uff0c\u9700\u8981\u5177\u4f53\u4ee3\u7801\u793a\u4f8b<\/p>\n

\u5728\u4f7f\u7528SQL\u8bed\u53e5\u8fdb\u884c\u6570\u636e\u67e5\u8be2\u65f6\uff0cWHERE\u5b50\u53e5\u662f\u975e\u5e38\u91cd\u8981\u7684\u4e00\u90e8\u5206\u3002\u5b83\u53ef\u4ee5\u7528\u6765\u7b5b\u9009\u51fa\u7b26\u5408\u7279\u5b9a\u6761\u4ef6\u7684\u6570\u636e\uff0c\u63d0\u4f9b\u4e86\u7075\u6d3b\u7684\u6570\u636e\u8fc7\u6ee4\u548c\u68c0\u7d22\u529f\u80fd\u3002\u672c\u6587\u5c06\u4ecb\u7ecdWHERE\u5b50\u53e5\u7684\u51e0\u79cd\u5e38\u89c1\u7528\u6cd5\uff0c\u5e76\u63d0\u4f9b\u76f8\u5e94\u7684\u4ee3\u7801\u793a\u4f8b\u3002<\/p>\n

    \n
  1. \u7b80\u5355\u7684\u6761\u4ef6\u7b5b\u9009\uff1a
    WHERE\u5b50\u53e5\u6700\u57fa\u672c\u7684\u7528\u6cd5\u662f\u901a\u8fc7\u7ed9\u5b9a\u4e00\u4e2a\u6761\u4ef6\u5bf9\u6570\u636e\u8fdb\u884c\u7b5b\u9009\u3002\u4f8b\u5982\uff0c\u7b5b\u9009\u51fa\u540d\u5b57\u4e3a”John”\u7684\u5458\u5de5\u4fe1\u606f\uff0c\u53ef\u4ee5\u4f7f\u7528\u5982\u4e0b\u4ee3\u7801\uff1a<\/li>\n<\/ol>\n
    SELECT * FROM employees\nWHERE name = 'John';<\/pre>\n
      \n
    1. \u4f7f\u7528\u6bd4\u8f83\u64cd\u4f5c\u7b26\uff1a
      WHERE\u5b50\u53e5\u8fd8\u53ef\u4ee5\u4f7f\u7528\u6bd4\u8f83\u64cd\u4f5c\u7b26\uff08\u5982<\u3001>\u3001=\u3001<=\u3001>=\u3001<>\u7b49\uff09\u5bf9\u6570\u636e\u8fdb\u884c\u66f4\u590d\u6742\u7684\u6761\u4ef6\u7b5b\u9009\u3002\u4f8b\u5982\uff0c\u7b5b\u9009\u51fa\u5de5\u8d44\u5927\u4e8e5000\u7684\u5458\u5de5\u4fe1\u606f\uff0c\u53ef\u4ee5\u4f7f\u7528\u5982\u4e0b\u4ee3\u7801\uff1a<\/li>\n<\/ol>\n
      SELECT * FROM employees\nWHERE salary > 5000;<\/pre>\n
        \n
      1. \u4f7f\u7528\u903b\u8f91\u64cd\u4f5c\u7b26\uff1a
        WHERE\u5b50\u53e5\u8fd8\u53ef\u4ee5\u4f7f\u7528\u903b\u8f91\u64cd\u4f5c\u7b26\uff08\u5982AND\u3001OR\u3001NOT\uff09\u7ed3\u5408\u591a\u4e2a\u6761\u4ef6\u8fdb\u884c\u7b5b\u9009\u3002\u4f8b\u5982\uff0c\u7b5b\u9009\u51fa\u540d\u5b57\u4e3a”John”\u4e14\u5de5\u8d44\u5927\u4e8e5000\u7684\u5458\u5de5\u4fe1\u606f\uff0c\u53ef\u4ee5\u4f7f\u7528\u5982\u4e0b\u4ee3\u7801\uff1a<\/li>\n<\/ol>\n
        SELECT * FROM employees\nWHERE name = 'John' AND salary > 5000;<\/pre>\n
          \n
        1. \u4f7f\u7528\u901a\u914d\u7b26\uff1a
          WHERE\u5b50\u53e5\u8fd8\u652f\u6301\u4f7f\u7528\u901a\u914d\u7b26\u8fdb\u884c\u6a21\u7cca\u5339\u914d\u3002\u4f8b\u5982\uff0c\u7b5b\u9009\u51fa\u4ee5”J”\u5f00\u5934\u7684\u5458\u5de5\u4fe1\u606f\uff0c\u53ef\u4ee5\u4f7f\u7528\u5982\u4e0b\u4ee3\u7801\uff1a<\/li>\n<\/ol>\n
          SELECT * FROM employees\nWHERE name LIKE 'J%';<\/pre>\n
            \n
          1. \u4f7f\u7528IN\u64cd\u4f5c\u7b26\uff1a
            WHERE\u5b50\u53e5\u8fd8\u652f\u6301\u4f7f\u7528IN\u64cd\u4f5c\u7b26\u6765\u7b5b\u9009\u6ee1\u8db3\u4e00\u7ec4\u503c\u4e2d\u7684\u4efb\u610f\u4e00\u4e2a\u7684\u6570\u636e\u3002\u4f8b\u5982\uff0c\u7b5b\u9009\u51fa\u540d\u5b57\u4e3a”John”\u6216”Mike”\u7684\u5458\u5de5\u4fe1\u606f\uff0c\u53ef\u4ee5\u4f7f\u7528\u5982\u4e0b\u4ee3\u7801\uff1a<\/li>\n<\/ol>\n
            SELECT * FROM employees\nWHERE name IN ('John', 'Mike');<\/pre>\n
              \n
            1. \u4f7f\u7528BETWEEN\u548cAND\u64cd\u4f5c\u7b26\uff1a
              WHERE\u5b50\u53e5\u8fd8\u652f\u6301\u4f7f\u7528BETWEEN\u548cAND\u64cd\u4f5c\u7b26\u6765\u7b5b\u9009\u4ecb\u4e8e\u4e24\u4e2a\u503c\u4e4b\u95f4\u7684\u6570\u636e\u3002\u4f8b\u5982\uff0c\u7b5b\u9009\u51fa\u5de5\u8d44\u57285000\u523010000\u4e4b\u95f4\u7684\u5458\u5de5\u4fe1\u606f\uff0c\u53ef\u4ee5\u4f7f\u7528\u5982\u4e0b\u4ee3\u7801\uff1a<\/li>\n<\/ol>\n
              SELECT * FROM employees\nWHERE salary BETWEEN 5000 AND 10000;<\/pre>\n
                \n
              1. \u4f7f\u7528NULL\u548cIS NULL\u64cd\u4f5c\u7b26\uff1a
                WHERE\u5b50\u53e5\u8fd8\u652f\u6301\u4f7f\u7528NULL\u548cIS NULL\u64cd\u4f5c\u7b26\u6765\u7b5b\u9009\u7a7a\u503c\uff08NULL\uff09\u6216\u975e\u7a7a\u503c\u3002\u4f8b\u5982\uff0c\u7b5b\u9009\u51fa\u6ca1\u6709\u5206\u914d\u90e8\u95e8\u7684\u5458\u5de5\u4fe1\u606f\uff0c\u53ef\u4ee5\u4f7f\u7528\u5982\u4e0b\u4ee3\u7801\uff1a<\/li>\n<\/ol>\n
                SELECT * FROM employees\nWHERE department IS NULL;<\/pre>\n
                \u603b\u7ed3\u8d77\u6765\uff0cWHERE\u5b50\u53e5\u5728SQL\u8bed\u53e5\u4e2d\u7684\u4f7f\u7528\u975e\u5e38\u7075\u6d3b\uff0c\u53ef\u4ee5\u6839\u636e\u5177\u4f53\u7684\u9700\u6c42\u8fdb\u884c\u5404\u79cd\u6761\u4ef6\u7b5b\u9009\u3002\u672c\u6587\u4ecb\u7ecd\u4e86WHERE\u5b50\u53e5\u7684\u51e0\u79cd\u5e38\u89c1\u7528\u6cd5\uff0c\u5e76\u63d0\u4f9b\u4e86\u76f8\u5e94\u7684\u4ee3\u7801\u793a\u4f8b\uff0c\u5e0c\u671b\u5bf9\u8bfb\u8005\u5728\u7f16\u5199SQL\u67e5\u8be2\u8bed\u53e5\u65f6\u6709\u6240\u5e2e\u52a9\u3002<\/p>\n
                \u7406\u8bba\u8981\u638c\u63e1\uff0c\u5b9e\u64cd\u4e0d\u80fd\u843d\uff01\u4ee5\u4e0a\u5173\u4e8e\u300aSQL\u4e2dWHERE\u5b50\u53e5\u7684\u7528\u6cd5\u53ca\u793a\u4f8b\u300b\u7684\u8be6\u7ec6\u4ecb\u7ecd\uff0c\u5927\u5bb6\u90fd\u638c\u63e1\u4e86\u5427\uff01\u5982\u679c\u60f3\u8981\u7ee7\u7eed\u63d0\u5347\u81ea\u5df1\u7684\u80fd\u529b\uff0c\u90a3\u4e48\u5c31\u6765\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\u5427\uff01<\/p>\n
                \n
                \n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"
                SQL\u4e2dWHERE\u5b50\u53e5\u7684\u7528\u6cd5\u53ca\u793a...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-199683","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/199683","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=199683"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/199683\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=199683"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=199683"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=199683"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}