{"id":10020546,"date":"2024-12-24T12:07:02","date_gmt":"2024-12-24T04:07:02","guid":{"rendered":"https:\/\/itmax.cn\/?p=10020546"},"modified":"2024-12-24T12:07:02","modified_gmt":"2024-12-24T04:07:02","slug":"mysql%ef%bc%9a%e5%85%b3%e4%ba%8e%e6%9f%a5%e8%af%a2%e7%9a%84%e9%82%a3%e4%ba%9b%e4%ba%8b%e5%84%bf","status":"publish","type":"post","link":"https:\/\/itmax.cn\/?p=10020546","title":{"rendered":"Mysql\uff1a\u5173\u4e8e\u67e5\u8be2\u7684\u90a3\u4e9b\u4e8b\u513f"},"content":{"rendered":"<p>Mysql\u4e00\u76f4\u90fd\u662f\u4e92\u8054\u7f51\u5f00\u53d1\u4e4b\u4e2d\u5e38\u7528\u7684\u7684\u4e00\u95e8\u8bed\u8a00\uff0c\u5176\u4e2d\u67e5\u8be2\u66f4\u662f\u5e38\u7528\u7684\u529f\u80fd\u4e4b\u4e00\uff0c\u4eca\u5929\u5c31\u6765\u8bf4\u8bf4\u5173\u4e8e\u67e5\u8be2\u7684\u90a3\u4e9b\u4e8b\u513f\u3002<\/p>\n<p>SELECT\u662fsql\u4e2d\u7684\u5173\u952e\u5b57\u4e4b\u4e00\uff0csql\u4e2d\u7684\u5173\u952e\u5b57\u8fd8\u6709INSERT\u3001DELETE\u3001UPDATE \u7b49\u5173\u952e\u5b57,\u5728\u8fd9\u7bc7\u6587\u7ae0\u4e2d\uff0c\u6211\u4eec\u53ea\u8981\u8bb2\u8bb2\u5173\u4e8eSELECT\u7684\u90e8\u5206\uff1b<\/p>\n<ol>\n<li>\n<p>SELECT\u67e5\u8be2\u7684\u57fa\u7840\u8bed\u6cd5<br \/>  \u67e5\u8be2\u8868\u4e2d\u6240\u6709\u5217\u7684\u6570\u636e<\/p>\n<pre><code>SELECT *  FROM table <\/code><\/pre>\n<p>\u4e5f\u53ef\u4ee5\u67e5\u8be2\u8868\u4e2d\u4e00\u4e2a\u6216\u8005\u591a\u4e2a\u5217\u7684\u6570\u636e\uff0c\u5728\u5217\u660e\u4e4b\u95f4\u7528\u9017\u53f7 ,\u5206\u5272\u5373\u53ef\u3002<\/p>\n<pre><code>SELECT column_1,column_2,column_3,column_4 FROM table<\/code><\/pre>\n<p>\u8d77\u522b\u540d\u67e5\u8be2<\/p>\n<pre><code>SELECT column_1 as name FROM table <\/code><\/pre>\n<p>\u53bb\u91cd\u67e5\u8be2,\u4ece\u67e5\u8be2\u7ed3\u679c\u4e2d\u53bb\u6389\u91cd\u590d\u7684\u884c\uff0c\u4f7f\u7528\u7684\u662f\u5173\u952e\u5b57DISTINCT\uff0c\u5e76\u4e14\uff0cDISTINCT\u9700\u8981\u653e\u5728\u5217\u7684\u524d\u9762\uff0c\u5982\u679c\u5199\u5728\u5217\u540e\u9762\u5c31\u4f1a\u62a5\u9519\u3002<\/p>\n<pre><code>SELECT DISTINCT column_1 FROM table<\/code><\/pre>\n<p>\u5206\u7ec4\u67e5\u8be2\uff0c\u901a\u5e38\u4f1a\u4e0e\u805a\u5408\u51fd\u6570\u653e\u5728\u4e00\u8d77\u4f7f\u7528\uff0c\u5c06\u7ed3\u679c\u96c6\u4e2d\u7684\u591a\u884c\u6570\u636e\u6839\u636e\u4e00\u4e2a\u6216\u8005\u591a\u4e2a\u5217\u8fdb\u884c\u5206\u7ec4\uff0c     <br \/>  \u4f7f\u7528 GROUP BY \u53ef\u4ee5\u5bf9\u6bcf\u4e2a\u5206\u7ec4\u8fdb\u884c\u805a\u5408\u8ba1\u7b97\uff0c\u800c\u4e0d\u662f\u5bf9\u6574\u4e2a\u7ed3\u679c\u96c6\u8fdb\u884c\u8ba1\u7b97\u3002<\/p>\n<pre><code>SELECT  column_1,column_2,FROM  table  GROUP BY column_1\n<\/code><\/pre>\n<p>\u4f7f\u7528 HAVING \u5b50\u53e5\uff0cHAVING \u5b50\u53e5\u4e0e GROUP BY \u4e00\u8d77\u4f7f\u7528\uff0c\u7528\u4e8e\u5bf9\u5206\u7ec4\u540e\u7684\u7ed3\u679c\u8fdb\u884c\u8fc7\u6ee4\uff1a<\/p>\n<pre><code>SELECT column_1, SUM(column_2) AS total_num\nFROM table\nGROUP BY column_1\nHAVING total_num &gt; 10;<\/code><\/pre>\n<p>\u4ee5\u4e0asql\u5c31\u662f\u6309\u7167\u5b57\u6bb5column_1\u8fdb\u884c\u5206\u7ec4\u67e5\u8be2column_2\u7684\u603b\u6570\u4fe1\u606f\uff0c\u5e76\u4e14\u8fd4\u56de\u603b\u6570\u8981\u5927\u4e8e10\u7684\u6240\u6709\u6570\u636e<\/p>\n<\/li>\n<\/ol>\n<ul>\n<li>\u67e5\u8be2\u7ed3\u679c\u6392\u5e8f\uff0c\u6bd4\u5982\u6392\u884c\u699c\u7b49\u6570\u636e\u9700\u8981\u6309\u7167\u5927\u5c0f\u987a\u5e8f\u5bf9\u67e5\u8be2\u7ed3\u679c\u8fdb\u884c\u6392\u5e8f\uff0c\u5c31\u9700\u8981\u4f7f\u7528 ORDER BY \u5b50\u53e5\u3002\u4f7f\u7528 ORDER BY \u5b50\u53e5\u6709\u4ee5\u4e0b\u51e0\u4e2a\u70b9\u9700\u8981\u6ce8\u610f\uff1a<br \/>1\u3001ORDER BY\u540e\u9762\u662f\u9700\u8981\u6392\u5e8f\u7684\u5217\u540d\uff0c\u53ef\u4ee5\u662f\u4e00\u4e2a\u6216\u8005\u591a\u4e2a\uff0c\u4f1a\u6309\u7167\u540e\u9762\u7684\u5217\u540d\u5148\u540e\u8fdb\u884c\u6392\u5e8f\u64cd\u4f5c\uff1b<br \/>2\u3001ORDER BY\u540e\u9762\u53ef\u4ee5\u8bbe\u7f6e\u6392\u5217\u7684\u987a\u5e8f\uff0c\u5728\u5217\u540d\u540e\u9762\u6dfb\u52a0 ASC\u6216\u8005DESC\uff0cASC \u4ee3\u8868\u9012\u589e\u6392\u5e8f\uff0cDESC       \u4ee3\u8868\u9012\u51cf\u6392\u5e8f\uff0c\u5982\u679c\u6ca1\u6709\u8bbe\u7f6e\uff0c\u4f1a\u9ed8\u8ba4\u6309\u7167ASC\u5347\u5e8f\u6392\u5217\uff0c\u5373\u4fbf\u662fselect\u4e2d\u6ca1\u6709\u67e5\u8be2\u7684\u5217\u540d\u4e5f\u53ef\u4ee5       \u5728ORDER BY\u540e\u9762\u8bbe\u7f6e\u6392\u5e8f\uff1bORDER BY\u8981\u5728SELECT\u8bed\u53e5\u7684\u6700\u540e\uff0c\u5426\u5219\u4f1a\u62a5\u9519\u3002<\/li>\n<\/ul>\n<p>\u5f53\u6211\u4eec\u9700\u8981\u6309\u7167column_1\u6570\u503c\u7684\u4ece\u9ad8\u5230\u4f4e\u8fdb\u884c\u67e5\u8be2\u7ed3\u679c\u6392\u5e8f\u7684\u65f6\u5019\uff0csql\u5982\u4e0b<\/p>\n<pre><code>SELECT column_1,column_2 FROM table ORDER BY column_1 DESC\n<\/code><\/pre>\n<p>\u5f53\u6211\u4eec\u60f3\u8981\u9650\u5b9a\u8fd4\u56de\u7ed3\u679c\u7684\u6570\u91cf\u7684\u65f6\u5019\uff0c\u4f7f\u7528 LIMIT \u5173\u952e\u5b57\uff0c\u6bd4\u5982\u5728\u4e0a\u4e00\u4e2a\u67e5\u8be2\u4f8b\u5b50\u4e2d\u53ea\u60f3\u67e5\u8be2\u524d10\u6761\u6570\u636e<\/p>\n<pre><code>SELECT column_1,column_2 FROM table ORDER BY column_1 DESC  LIMIT 10<\/code><\/pre>\n<ol start=\"2\">\n<li>\n<p>\u5173\u4e8eSELECT\u67e5\u8be2\u7684\u6267\u884c\u987a\u5e8f\uff0c\u67e5\u8be2\u53ef\u4ee5\u8bf4\u662f\u9488\u5bf9\u6570\u636e\u5e93\u6700\u9891\u7e41\u7684\u64cd\u4f5c\uff0c\u6211\u4eec\u5728\u67e5\u8be2\u8fc7\u7a0b\u4e2d\u8981\u6ce8\u610f\u51e0\u4e2a\u5173\u952e\u70b9\uff1a<\/p>\n<p>\u5173\u952e\u5b57\u5fc5\u987b\u6309\u7167\u987a\u5e8f\u7f16\u5199\uff0c\u6bd4\u5982\u8bb2\u6211\u4eec\u4ee5\u4e0a\u8bb2\u8fc7\u7684\u6240\u6709\u5173\u952e\u5b57\u90fd\u653e\u5230\u4e00\u4e2a\u67e5\u8be2\u8bed\u53e5\u4e2d\uff0c\u90a3\u4e48\u987a\u5e8f\u662f\uff1a<\/p>\n<pre><code>SELECT  DISTINCT ...... FROM ...... WHERE ......GROUP BY...... ORDER BY ...... ASC.....LIMIT ......<\/code><\/pre>\n<ul>\n<li>SELECT \u8bed\u53e5\u7684\u6267\u884c\u987a\u5e8f\uff1a<\/li>\n<\/ul>\n<pre><code>FROM &gt; WHERE &gt; GROUP BY &gt; HAVING &gt; SELECT\u7684\u5b57\u6bb5 &gt; DISTINCT &gt; ORDER BY &gt;    LIMIT<\/code><\/pre>\n<ul>\n<li>\u5982\u679c\u5199\u4e86\u4e00\u4e2a\u590d\u6742\u67e5\u8be2\u7684sql\uff0c\u90a3\u4e48\u5b83\u7684\u6267\u884c\u987a\u5e8f\u5982\u4e0b<\/li>\n<\/ul>\n<pre><code>SELECT DISTINCT column_1, column_2, count(*) as num #\u987a\u5e8f5\nFROM table  #\u987a\u5e8f1\nWHERE column_2 = 10 #\u987a\u5e8f2\nGROUP BY column_1 #\u987a\u5e8f3\nHAVING num &gt; 10 #\u987a\u5e8f4\nORDER BY num DESC #\u987a\u5e8f6\nLIMIT 10 #\u987a\u5e8f7<\/code><\/pre>\n<\/li>\n<li>\u5173\u4e8e\u67e5\u8be2\u7684\u4f18\u5316\uff1a<\/li>\n<\/ol>\n<ul>\n<li>\n<p>\u5982\u679c\u4e0d\u9700\u8981\u5c06\u4e00\u4e2a\u8868\u4e2d\u7684\u6240\u6709\u5217\u90fd\u67e5\u8be2\u51fa\u6765\u7684\u65f6\u5019\uff0c\u5c3d\u91cf\u4e0d\u8981\u4f7f\u7528SELECT* \u67e5\u8be2\uff0c\u800c\u662fSELECT\u5173\u952e\u5b57\u540e\u9762\u6dfb\u52a0\u5177\u4f53\u7684\u9700\u8981\u67e5\u8be2\u7684\u5b57\u6bb5\uff0c\u8fd9\u6837\u4e0d\u9700\u8981\u68c0\u7d22\u51fa\u6240\u6709\u7684\u5217\uff0c\u51cf\u5c11\u4e86\u5728\u67e5\u8be2\u4e2d\u7684\u4f20\u8f93\u91cf\uff1b<\/p>\n<ul>\n<li>\u521b\u5efa\u5408\u9002\u7684\u7d22\u5f15\uff1a<br \/>\u5355\u5217\u7d22\u5f15\uff1a\u4e3a\u7ecf\u5e38\u7528\u4e8e\u8fc7\u6ee4\u3001\u6392\u5e8f\u6216\u5206\u7ec4\u7684\u5217\u521b\u5efa\u7d22\u5f15\u3002<br \/>\u590d\u5408\u7d22\u5f15\uff1a\u5982\u679c\u67e5\u8be2\u6761\u4ef6\u7ecf\u5e38\u6d89\u53ca\u591a\u4e2a\u5217\uff0c\u5219\u521b\u5efa\u5305\u542b\u8fd9\u4e9b\u5217\u7684\u590d\u5408\u7d22\u5f15\u3002<br \/>\u4f7f\u7528\u524d\u7f00\u7d22\u5f15\uff1a\u5bf9\u4e8eVARCHAR\u7c7b\u578b\u7684\u5217\uff0c\u5982\u679c\u5217\u7684\u6587\u672c\u5f88\u957f\uff0c\u5219\u53ef\u4ee5\u4f7f\u7528\u524d\u7f00\u7d22\u5f15\u3002<\/li>\n<li>\u907f\u514d\u5168\u8868\u626b\u63cf<br \/>\u4f7f\u7528WHERE\u5b50\u53e5\u6765\u9650\u5236\u67e5\u8be2\u7684\u7ed3\u679c\u96c6\u3002<br \/>\u907f\u514d\u5728WHERE\u5b50\u53e5\u4e2d\u4f7f\u7528LIKE &#8216;%value%&#8217;\uff0c\u56e0\u4e3a\u8fd9\u4f1a\u5bfc\u81f4\u5168\u8868\u626b\u63cf\u3002<\/li>\n<li>\u4f18\u5316\u67e5\u8be2\u4e2d\u7684\u51fd\u6570\u4f7f\u7528<br \/>\u5c3d\u91cf\u907f\u514d\u5728WHERE\u5b50\u53e5\u4e2d\u4f7f\u7528\u51fd\u6570\uff0c\u56e0\u4e3a\u8fd9\u4f1a\u5bfc\u81f4\u7d22\u5f15\u5931\u6548\u3002<br \/>\u5982\u679c\u5fc5\u987b\u4f7f\u7528\u51fd\u6570\uff0c\u8003\u8651\u4f7f\u7528\u751f\u6210\u5217\uff08generated column\uff09\u6765\u5b58\u50a8\u8ba1\u7b97\u7ed3\u679c\uff0c\u5e76\u5bf9\u8be5\u5217     \u5efa\u7acb\u7d22\u5f15\u3002<\/li>\n<li>\u4f18\u5316\u5b50\u67e5\u8be2\u548c\u8fde\u63a5<br \/>\u4f7f\u7528JOIN\u4ee3\u66ff\u5b50\u67e5\u8be2\uff0c\u901a\u5e38JOIN\u7684\u6267\u884c\u6548\u7387\u66f4\u9ad8\u3002<br \/>\u5f53\u4f7f\u7528JOIN\u65f6\uff0c\u786e\u4fdd\u8fde\u63a5\u6761\u4ef6\u4f7f\u7528\u4e86\u7d22\u5f15\u3002<br \/>\u5c3d\u53ef\u80fd\u4f7f\u7528INNER JOIN\uff0c\u56e0\u4e3a\u5b83\u901a\u5e38\u6bd4OUTER JOIN\u66f4\u9ad8\u6548\u3002<\/li>\n<li>\u4f18\u5316LIMIT\u4f7f\u7528<br \/>\u5982\u679c\u4f7f\u7528LIMIT\u6765\u5206\u9875\uff0c\u5c3d\u91cf\u907f\u514d\u4f7f\u7528\u5927\u7684\u504f\u79fb\u91cf\u3002\u53ef\u4ee5\u8003\u8651\u4f7f\u7528\u201c\u8bb0\u4f4f\u4e0a\u6b21\u6700\u5927ID\u201d\u7684\u65b9\u6cd5\u6765\u4f18\u5316\u3002<\/li>\n<li>\u4f7f\u7528UNION ALL\u4ee3\u66ffUNION<br \/>\u5982\u679c\u4f60\u7684\u67e5\u8be2\u9700\u8981\u4f7f\u7528UNION\uff0c\u5e76\u4e14\u4f60\u77e5\u9053\u6570\u636e\u4e2d\u4e0d\u4f1a\u6709\u91cd\u590d\uff0c\u4f7f\u7528UNION ALL\uff0c\u56e0\u4e3a\u5b83\u4e0d\u4f1a\u53bb\u91cd\uff0c\u56e0\u6b64\u901a\u5e38\u66f4\u5feb\u3002<\/li>\n<li>\u4f18\u5316\u6570\u636e\u7c7b\u578b<br \/>\u9009\u62e9\u5408\u9002\u7684\u6570\u636e\u7c7b\u578b\u53ef\u4ee5\u51cf\u5c11\u5b58\u50a8\u7a7a\u95f4\uff0c\u63d0\u9ad8\u67e5\u8be2\u6548\u7387\u3002<br \/>\u4f8b\u5982\uff0c\u5bf9\u4e8e\u56fa\u5b9a\u957f\u5ea6\u7684\u5b57\u7b26\u4e32\uff0c\u53ef\u4ee5\u4f7f\u7528CHAR\uff1b\u5bf9\u4e8e\u53ef\u53d8\u957f\u5ea6\u7684\u5b57\u7b26\u4e32\uff0c\u4f7f\u7528VARCHAR\u3002<\/li>\n<li>\u4f18\u5316\u5b58\u50a8\u8fc7\u7a0b<br \/>\u5982\u679c\u4f7f\u7528\u5b58\u50a8\u8fc7\u7a0b\uff0c\u786e\u4fdd\u5b83\u4eec\u88ab\u4f18\u5316\u4ee5\u51cf\u5c11\u4e0d\u5fc5\u8981\u7684\u6570\u636e\u5e93\u8c03\u7528\u3002<\/li>\n<li>\u4f7f\u7528\u7f13\u5b58<br \/>\u5982\u679c\u4f60\u7684\u5e94\u7528\u573a\u666f\u9002\u5408\uff0c\u53ef\u4ee5\u542f\u7528MySQL\u7684\u67e5\u8be2\u7f13\u5b58\u6765\u63d0\u9ad8\u67e5\u8be2\u6548\u7387\u3002<\/li>\n<li>\u5927\u578b\u6570\u636e\u5e93\u4f7f\u7528\u5206\u533a\u8868\u6216\u8005\u4e91\u5b58\u50a8\u6765\u63d0\u9ad8\u67e5\u8be2\u6548\u7387<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><a href=\"https:\/\/segmentfault.com\/a\/1190000045673183\">https:\/\/segmentfault.com\/a\/1190000045673183<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Mysql\u4e00\u76f4\u90fd\u662f\u4e92\u8054\u7f51\u5f00\u53d1\u4e4b\u4e2d\u5e38\u7528\u7684\u7684\u4e00\u95e8\u8bed\u8a00\uff0c\u5176\u4e2d\u67e5\u8be2\u66f4\u662f\u5e38\u7528\u7684\u529f\u80fd\u4e4b\u4e00\uff0c\u4eca\u5929\u5c31\u6765\u8bf4\u8bf4\u5173\u4e8e\u67e5\u8be2\u7684\u90a3\u4e9b\u4e8b\u513f\u3002 [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[4],"tags":[],"class_list":["post-10020546","post","type-post","status-publish","format-standard","hentry","category-share"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10020546","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10020546"}],"version-history":[{"count":0,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10020546\/revisions"}],"wp:attachment":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10020546"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10020546"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10020546"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}