{"id":344,"date":"2013-01-03T18:29:08","date_gmt":"2013-01-03T10:29:08","guid":{"rendered":"http:\/\/www.cnmiss.cn\/?p=344"},"modified":"2013-02-18T16:10:36","modified_gmt":"2013-02-18T08:10:36","slug":"mysql-5-1%e5%88%86%e5%8c%ba%e6%8a%80%e6%9c%af%e5%88%9d%e6%8e%a2%ef%bc%88%e4%ba%94%ef%bc%89","status":"publish","type":"post","link":"https:\/\/www.cnmiss.cn\/?p=344","title":{"rendered":"MySQL 5.1\u5206\u533a\u6280\u672f\u521d\u63a2\uff08\u4e94\uff09"},"content":{"rendered":"<p>3.1 \u5355\u8868\u67e5\u8be2<br \/>\n\u4ece\u9500\u552e\u8bb0\u5f55\u4e2d\u627e\u52301999\u5e74\u6574\u5e74\u7684\u9500\u552e\u8bb0\u5f55\u6709\u591a\u5c11\u6761\uff0c\u8fd9\u4e2a\u5f88\u7b80\u5355\uff0c\u67e5\u8be2\u8bed\u53e5\u5982\u4e0b\uff1a<br \/>\nselect count(*) from salaries s where s.from_date between &#8220;1999-01-01&#8221; and &#8220;1999-12-31&#8221; ;<br \/>\n\u90a3\u4e48\u5bf9\u4e8e\u5206\u533a\u524d\u540e\u7684\u67e5\u8be2\u6027\u80fd\u5374\u6709\u5f88\u5927\u7684\u5dee\u522b\uff1a<br \/>\n<img loading=\"lazy\" decoding=\"async\" title=\"MySQL 5.1\u5206\u533a\u6280\u672f\u521d\u63a2\uff08\u4e94\uff09 - \u7b2c1\u5f20  | \u6211\u7684\u535a\u5ba2 - \u6280\u672f\u5206\u4eab\" alt=\"MySQL 5.1\u5206\u533a\u6280\u672f\u521d\u63a2\uff08\u4e94\uff09 - \u7b2c1\u5f20  | \u6211\u7684\u535a\u5ba2 - \u6280\u672f\u5206\u4eab\" alt=\"\" src=\"https:\/\/www.cnmiss.cn\/wp-content\/uploads\/2013\/01\/5776291_1281520880dzPZ.png\" width=\"581\" height=\"172\" \/><br \/>\n\u901a\u8fc7\u5982\u4e0a\u53ef\u77e5\uff0c\u5229\u7528\u5206\u533a\u4e4b\u540e\u5b83\u53ea\u9700\u626b\u63cfp16\u5206\u533a\uff0c\u8bbf\u95ee\u7684\u8bb0\u5f55\u660e\u663e\u51cf\u5c11\uff0c\u6240\u4ee5\u6027\u80fd\u81ea\u7136\u6709\u8f83\u5927\u7684\u63d0\u5347\uff1a<br \/>\n<img loading=\"lazy\" decoding=\"async\" title=\"MySQL 5.1\u5206\u533a\u6280\u672f\u521d\u63a2\uff08\u4e94\uff09 - \u7b2c2\u5f20  | \u6211\u7684\u535a\u5ba2 - \u6280\u672f\u5206\u4eab\" alt=\"MySQL 5.1\u5206\u533a\u6280\u672f\u521d\u63a2\uff08\u4e94\uff09 - \u7b2c2\u5f20  | \u6211\u7684\u535a\u5ba2 - \u6280\u672f\u5206\u4eab\" alt=\"\" src=\"https:\/\/www.cnmiss.cn\/wp-content\/uploads\/2013\/01\/5776291_12815209415bvM.png\" width=\"557\" height=\"137\" \/><br \/>\n\u65e0\u91c7\u7528\u5206\u533a\u6280\u672f \u91c7\u7528\u5206\u533a\u6280\u672f<br \/>\n3.2 \u5355\u8868\u67e5\u8be2-BAD Case<br \/>\n\u82e5\u73b0\u5728\u6709\u5982\u4e0b\u67e5\u8be2\uff1a<br \/>\nselect count(*) from salaries s where year(s.from_date)=1999;<br \/>\n\u90a3\u4e48\u5b83\u662f\u5426\u80fd\u591f\u5229\u7528\u5230\u5206\u533a\u6280\u672f\u5462\uff0c\u7b54\u6848\u662f\u5426\u5b9a\u7684\u3002\u4e3a\u4ec0\u4e48\u5462\uff0c\u56e0\u4e3a\u5206\u533a\u4e2d\u7684key\u662fs.from_date\uff0c\u800c\u4e0d\u662f year(s.from_date)\uff0cmysql\u5e76\u4e0d\u80fd\u5f88\u667a\u80fd\u5730\u5224\u65adyear\u662f1999\u7684\uff0c\u90a3\u4e48\u5b83\u5c31\u662f\u5206\u4e3ap16\u5206\u533a\uff0c\u8fd9\u4e2a\u53ef\u4ee5\u901a\u8fc7\u5982\u4e0b\u7684\u67e5\u8be2\u8ba1\u5212\u53ef\u4ee5\u8bc1 \u5b9e\uff1a<br \/>\n<img loading=\"lazy\" decoding=\"async\" title=\"MySQL 5.1\u5206\u533a\u6280\u672f\u521d\u63a2\uff08\u4e94\uff09 - \u7b2c3\u5f20  | \u6211\u7684\u535a\u5ba2 - \u6280\u672f\u5206\u4eab\" alt=\"MySQL 5.1\u5206\u533a\u6280\u672f\u521d\u63a2\uff08\u4e94\uff09 - \u7b2c3\u5f20  | \u6211\u7684\u535a\u5ba2 - \u6280\u672f\u5206\u4eab\" alt=\"\" src=\"https:\/\/www.cnmiss.cn\/wp-content\/uploads\/2013\/01\/5776291_12815209958Bgq.png\" width=\"557\" height=\"137\" \/><br \/>\n\u4e5f\u5c31\u662f\u5176\u5b9e\u5b83\u8bbf\u95ee\u4e86\u6240\u6709\u7684\u5206\u533a\uff0c\u6240\u4ee5\u5e76\u6ca1\u6709\u5f88\u597d\u5730\u5229\u7528\u5206\u533a\u529f\u80fd\uff0c\u5c06SQL\u6539\u5199\u5982\u4e0b\uff1a<br \/>\nselect count(*) from salaries s where year between &#8216;1999-01-01&#8217; and &#8216;1999-12-31&#8217; ;<br \/>\n\u5219\u67e5\u8be2\u8ba1\u5212\u5982\u4e0b\uff1a<br \/>\n<img loading=\"lazy\" decoding=\"async\" title=\"MySQL 5.1\u5206\u533a\u6280\u672f\u521d\u63a2\uff08\u4e94\uff09 - \u7b2c4\u5f20  | \u6211\u7684\u535a\u5ba2 - \u6280\u672f\u5206\u4eab\" alt=\"MySQL 5.1\u5206\u533a\u6280\u672f\u521d\u63a2\uff08\u4e94\uff09 - \u7b2c4\u5f20  | \u6211\u7684\u535a\u5ba2 - \u6280\u672f\u5206\u4eab\" alt=\"\" src=\"https:\/\/www.cnmiss.cn\/wp-content\/uploads\/2013\/01\/5776291_1281521047H5oA.png\" width=\"697\" height=\"187\" \/><br \/>\n\u53ef\u77e5\uff0c\u4e66\u5199\u6b63\u786e\u7684SQL\u53ef\u4ee5\u5b8c\u5168\u8868\u73b0\u51fa\u4e24\u79cd\u76f8\u5dee\u7279\u522b\u5927\u7684\u6027\u80fd\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>3.1 \u5355\u8868\u67e5\u8be2 \u4ece\u9500\u552e\u8bb0\u5f55\u4e2d\u627e\u52301999\u5e74\u6574\u5e74\u7684\u9500\u552e\u8bb0\u5f55\u6709\u591a\u5c11\u6761\uff0c\u8fd9\u4e2a\u5f88\u7b80\u5355\uff0c &hellip; <a href=\"https:\/\/www.cnmiss.cn\/?p=344\">\u7ee7\u7eed\u9605\u8bfb <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[24],"class_list":["post-344","post","type-post","status-publish","format-standard","hentry","category-xxbj","tag-mysql"],"_links":{"self":[{"href":"https:\/\/www.cnmiss.cn\/index.php?rest_route=\/wp\/v2\/posts\/344","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.cnmiss.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cnmiss.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cnmiss.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cnmiss.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=344"}],"version-history":[{"count":0,"href":"https:\/\/www.cnmiss.cn\/index.php?rest_route=\/wp\/v2\/posts\/344\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.cnmiss.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=344"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cnmiss.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=344"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cnmiss.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=344"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}