{"id":6346,"date":"2024-11-14T14:14:05","date_gmt":"2024-11-14T06:14:05","guid":{"rendered":"https:\/\/fwq.ai\/blog\/6346\/"},"modified":"2024-11-14T14:14:05","modified_gmt":"2024-11-14T06:14:05","slug":"mysql%e6%9b%bf%e6%8d%a2%e5%ad%97%e7%ac%a6%e4%b8%b2%e4%b8%ad%e7%9a%84%e6%9f%90%e4%b8%aa%e5%ad%97%e7%ac%a6","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/6346\/","title":{"rendered":"mysql\u66ff\u6362\u5b57\u7b26\u4e32\u4e2d\u7684\u67d0\u4e2a\u5b57\u7b26"},"content":{"rendered":"<blockquote><p>\n  mysql \u63d0\u4f9b\u4e86\u591a\u79cd\u66ff\u6362\u5b57\u7b26\u4e32\u5b57\u7b26\u7684\u65b9\u6cd5\uff0c\u5305\u62ec\uff1a1. replace() \u51fd\u6570\uff1b2. substr() \u548c concat() \u51fd\u6570\uff1b3. \u6b63\u5219\u8868\u8fbe\u5f0f\uff1b4. coalesce() \u51fd\u6570\u3002\u9009\u62e9\u5408\u9002\u7684\u65b9\u6cd5\u6839\u636e\u5177\u4f53\u60c5\u51b5\u800c\u5b9a\u3002\n<\/p><\/blockquote>\n<p><img decoding=\"async\" src=\"https:\/\/img.php.cn\/upload\/article\/202408\/01\/2024080102401747559.jpg\" class=\"aligncenter\" title=\"mysql\u66ff\u6362\u5b57\u7b26\u4e32\u4e2d\u7684\u67d0\u4e2a\u5b57\u7b26\u63d2\u56fe\" alt=\"mysql\u66ff\u6362\u5b57\u7b26\u4e32\u4e2d\u7684\u67d0\u4e2a\u5b57\u7b26\u63d2\u56fe\" \/><\/p>\n<p><strong>\u5982\u4f55\u7528 MySQL \u66ff\u6362\u5b57\u7b26\u4e32\u4e2d\u7684\u67d0\u4e2a\u5b57\u7b26<\/strong><\/p>\n<p>MySQL \u63d0\u4f9b\u4e86\u591a\u79cd\u65b9\u6cd5\u6765\u66ff\u6362\u5b57\u7b26\u4e32\u4e2d\u7684\u67d0\u4e2a\u5b57\u7b26\uff0c\u5305\u62ec\uff1a<\/p>\n<p><strong>1. REPLACE() \u51fd\u6570<\/strong><\/p>\n<p>REPLACE() \u51fd\u6570\u53ef\u4ee5\u5c06\u5b57\u7b26\u4e32\u4e2d\u7684\u67d0\u4e2a\u5b57\u7b26\u66ff\u6362\u4e3a\u53e6\u4e00\u4e2a\u5b57\u7b26\u3002<\/p>\n<pre>SELECT REPLACE('Hello', 'e', 'a');<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p>\u8f93\u51fa\uff1a<\/p>\n<pre>Hallo<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p><strong>2. SUBSTR() \u548c CONCAT() \u51fd\u6570<\/strong><\/p>\n<p>SUBSTR() \u51fd\u6570\u53ef\u4ee5\u63d0\u53d6\u5b57\u7b26\u4e32\u7684\u4e00\u90e8\u5206\uff0c\u800c CONCAT() \u51fd\u6570\u53ef\u4ee5\u62fc\u63a5\u5b57\u7b26\u4e32\u3002\u901a\u8fc7\u7ed3\u5408\u8fd9\u4e24\u4e2a\u51fd\u6570\uff0c\u6211\u4eec\u53ef\u4ee5\u66ff\u6362\u5b57\u7b26\u4e32\u4e2d\u7684\u67d0\u4e2a\u5b57\u7b26\u3002<\/p>\n<pre>SELECT CONCAT(SUBSTR('Hello', 1, 1), 'a', SUBSTR('Hello', 3));<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p>\u8f93\u51fa\uff1a<\/p>\n<pre>Hallo<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p><strong>3. \u4f7f\u7528\u6b63\u5219\u8868\u8fbe\u5f0f<\/strong><\/p>\n<p>MySQL \u7684 REGEXP_REPLACE() \u51fd\u6570\u53ef\u4ee5\u4f7f\u7528\u6b63\u5219\u8868\u8fbe\u5f0f\u6765\u66ff\u6362\u5b57\u7b26\u4e32\u4e2d\u7684\u67d0\u4e2a\u5b57\u7b26\u3002<\/p>\n<pre>SELECT REGEXP_REPLACE('Hello', 'e', 'a');<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p>\u8f93\u51fa\uff1a<\/p>\n<pre>Hallo<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p><strong>4. \u4f7f\u7528 COALESCE() \u51fd\u6570<\/strong><\/p>\n<p>COALESCE() \u51fd\u6570\u53ef\u4ee5\u5c06\u7a7a\u503c\u66ff\u6362\u4e3a\u53e6\u4e00\u4e2a\u503c\u3002\u6211\u4eec\u53ef\u4ee5\u5229\u7528\u5b83\u6765\u66ff\u6362\u5b57\u7b26\u4e32\u4e2d\u7684\u67d0\u4e2a\u5b57\u7b26\u3002<\/p>\n<pre>SELECT COALESCE(REPLACE('Hello', 'e', 'a'), 'Default Value');<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p>\u8f93\u51fa\uff1a<\/p>\n<pre>Hallo<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p>\u6839\u636e\u5177\u4f53\u60c5\u51b5\uff0c\u9009\u62e9\u6700\u5408\u9002\u7684\u65b9\u6cd5\u6765\u66ff\u6362\u5b57\u7b26\u4e32\u4e2d\u7684\u67d0\u4e2a\u5b57\u7b26\u3002<\/p>\n<p>\u4ee5\u4e0a\u5c31\u662f\u66ff\u6362\u5b57\u7b26\u4e32\u4e2d\u7684\u67d0\u4e2a\u5b57\u7b26\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u7f51\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>mysql \u63d0\u4f9b\u4e86\u591a\u79cd\u66ff\u6362\u5b57\u7b26\u4e32\u5b57\u7b26\u7684\u65b9\u6cd5\uff0c\u5305\u62ec\uff1a1. replace() \u51fd\u6570\uff1b2. substr() \u548c concat() \u51fd\u6570\uff1b3. \u6b63\u5219\u8868\u8fbe\u5f0f\uff1b4. coalesce() \u51fd\u6570\u3002\u9009\u62e9\u5408\u9002\u7684\u65b9\u6cd5\u6839\u636e\u5177\u4f53\u60c5\u51b5\u800c\u5b9a\u3002 \u5982\u4f55\u7528 MySQL \u66ff\u6362\u5b57\u7b26\u4e32\u4e2d\u7684\u67d0\u4e2a\u5b57\u7b26 MySQL \u63d0\u4f9b\u4e86\u591a\u79cd\u65b9\u6cd5\u6765\u66ff\u6362\u5b57\u7b26\u4e32\u4e2d\u7684\u67d0\u4e2a\u5b57\u7b26\uff0c\u5305\u62ec\uff1a 1. REPLACE() \u51fd\u6570 REPLACE() \u51fd\u6570\u53ef\u4ee5\u5c06\u5b57\u7b26\u4e32\u4e2d\u7684\u67d0\u4e2a\u5b57\u7b26\u66ff\u6362\u4e3a\u53e6\u4e00\u4e2a\u5b57\u7b26\u3002 SELECT REPLACE(&#8216;Hello&#8217;, &#8216;e&#8217;, &#8216;a&#8217;); \u767b\u5f55\u540e\u590d\u5236 \u8f93\u51fa\uff1a Hallo \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 2. SUBSTR() \u548c CONCAT() \u51fd\u6570 SUBSTR() \u51fd\u6570\u53ef\u4ee5\u63d0\u53d6\u5b57\u7b26\u4e32\u7684\u4e00\u90e8\u5206\uff0c\u800c CONCAT() \u51fd\u6570\u53ef\u4ee5\u62fc\u63a5\u5b57\u7b26\u4e32\u3002\u901a\u8fc7\u7ed3\u5408\u8fd9\u4e24\u4e2a\u51fd\u6570\uff0c\u6211\u4eec\u53ef\u4ee5\u66ff\u6362\u5b57\u7b26\u4e32\u4e2d\u7684\u67d0\u4e2a\u5b57\u7b26\u3002 SELECT CONCAT(SUBSTR(&#8216;Hello&#8217;, 1, 1), &#8216;a&#8217;, SUBSTR(&#8216;Hello&#8217;, 3)); \u767b\u5f55\u540e\u590d\u5236 \u8f93\u51fa\uff1a Hallo \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 \u767b\u5f55\u540e\u590d\u5236 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[],"class_list":["post-6346","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/6346","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/comments?post=6346"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/6346\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=6346"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=6346"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=6346"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}