{"id":5404,"date":"2024-11-14T08:00:52","date_gmt":"2024-11-14T00:00:52","guid":{"rendered":"https:\/\/fwq.ai\/blog\/5404\/"},"modified":"2024-11-14T08:00:52","modified_gmt":"2024-11-14T00:00:52","slug":"mysql%e6%80%8e%e4%b9%88%e4%bf%ae%e6%94%b9%e5%ad%97%e6%ae%b5%e5%b1%9e%e6%80%a7","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/5404\/","title":{"rendered":"mysql\u600e\u4e48\u4fee\u6539\u5b57\u6bb5\u5c5e\u6027"},"content":{"rendered":"<blockquote><p>\n  \u4fee\u6539 mysql \u5b57\u6bb5\u5c5e\u6027\u7684\u65b9\u6cd5\u6709\u56db\u79cd\uff1a1. \u4f7f\u7528 alter table \u8bed\u53e5\u4fee\u6539\u5b57\u6bb5\u540d\u79f0\u3001\u6570\u636e\u7c7b\u578b\u3001\u7ea6\u675f\u7b49\uff1b2. \u4f7f\u7528 change \u8bed\u53e5\u91cd\u547d\u540d\u5b57\u6bb5\u6216\u540c\u65f6\u4fee\u6539\u540d\u79f0\u548c\u5c5e\u6027\uff1b3. \u4f7f\u7528 add column \u8bed\u53e5\u6dfb\u52a0\u65b0\u5b57\u6bb5\uff1b4. \u4f7f\u7528 drop column \u8bed\u53e5\u5220\u9664\u5b57\u6bb5\u3002\n<\/p><\/blockquote>\n<p><img decoding=\"async\" src=\"https:\/\/img.php.cn\/upload\/article\/202405\/28\/2024052811122563636.jpg\" class=\"aligncenter\" title=\"mysql\u600e\u4e48\u4fee\u6539\u5b57\u6bb5\u5c5e\u6027\u63d2\u56fe\" alt=\"mysql\u600e\u4e48\u4fee\u6539\u5b57\u6bb5\u5c5e\u6027\u63d2\u56fe\" \/><\/p>\n<p><strong>\u5982\u4f55\u4fee\u6539 MySQL \u5b57\u6bb5\u5c5e\u6027<\/strong><\/p>\n<p><strong>\u524d\u8a00\uff1a<\/strong><br \/>\u4fee\u6539 MySQL \u8868\u4e2d\u5b57\u6bb5\u7684\u5c5e\u6027\u5bf9\u4e8e\u4f18\u5316\u6570\u636e\u5e93\u7ed3\u6784\u548c\u4fdd\u6301\u6570\u636e\u5b8c\u6574\u6027\u81f3\u5173\u91cd\u8981\u3002\u672c\u6587\u5c06\u8be6\u7ec6\u4ecb\u7ecd\u4fee\u6539\u5b57\u6bb5\u5c5e\u6027\u7684\u4e0d\u540c\u65b9\u6cd5\u3002<\/p>\n<p><strong>\u4fee\u6539\u5b57\u6bb5\u5c5e\u6027\u7684\u65b9\u6cd5\uff1a<\/strong><\/p>\n<p><strong>1. \u4f7f\u7528 ALTER TABLE \u8bed\u53e5<\/strong><\/p>\n<p>ALTER TABLE \u8bed\u53e5\u662f\u6700\u5e38\u7528\u7684\u65b9\u6cd5\u6765\u4fee\u6539\u5b57\u6bb5\u5c5e\u6027\u3002\u5b83\u5141\u8bb8\u60a8\u4fee\u6539\u5b57\u6bb5\u7684\u6570\u636e\u7c7b\u578b\u3001\u9ed8\u8ba4\u503c\u3001\u53ef\u4e3a\u7a7a\u6027\u3001\u552f\u4e00\u6027\u7ea6\u675f\u7b49\u3002<\/p>\n<p><strong>\u8bed\u6cd5\uff1a<\/strong><\/p>\n<pre>ALTER TABLE table_name MODIFY column_name data_type [constraints];<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p>\u4f8b\u5982\uff0c\u5c06\u8868 users \u4e2d\u7684\u5b57\u6bb5 email \u4ece VARCHAR(255) \u4fee\u6539\u4e3a VARCHAR(500)\uff1a<\/p>\n<pre>ALTER TABLE users MODIFY email VARCHAR(500);<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p><strong>2. \u4f7f\u7528 CHANGE \u8bed\u53e5<\/strong><\/p>\n<p>CHANGE \u8bed\u53e5\u662f ALTER TABLE \u8bed\u53e5\u7684\u66ff\u4ee3\u65b9\u6cd5\u3002\u5b83\u7528\u4e8e\u91cd\u547d\u540d\u5b57\u6bb5\u6216\u540c\u65f6\u4fee\u6539\u5b57\u6bb5\u7684\u540d\u79f0\u548c\u5c5e\u6027\u3002<\/p>\n<p><strong>\u8bed\u6cd5\uff1a<\/strong><\/p>\n<pre>ALTER TABLE table_name CHANGE old_column_name new_column_name data_type [constraints];<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p>\u4f8b\u5982\uff0c\u5c06\u8868 users \u4e2d\u7684\u5b57\u6bb5 name \u91cd\u547d\u540d\u4e3a full_name\uff1a<\/p>\n<pre>ALTER TABLE users CHANGE name full_name VARCHAR(255);<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p><strong>3. \u4f7f\u7528 ADD COLUMN \u8bed\u53e5<\/strong><\/p>\n<p>ADD COLUMN \u8bed\u53e5\u7528\u4e8e\u5411\u8868\u4e2d\u6dfb\u52a0\u65b0\u7684\u5b57\u6bb5\u3002\u5b83\u6307\u5b9a\u5b57\u6bb5\u7684\u540d\u79f0\u3001\u6570\u636e\u7c7b\u578b\u548c\u4efb\u4f55\u5176\u4ed6\u7ea6\u675f\u3002<\/p>\n<p><strong>\u8bed\u6cd5\uff1a<\/strong><\/p>\n<pre>ALTER TABLE table_name ADD COLUMN column_name data_type [constraints];<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p>\u4f8b\u5982\uff0c\u5411\u8868 users \u4e2d\u6dfb\u52a0\u4e00\u4e2a\u65b0\u7684\u5b57\u6bb5 age\uff1a<\/p>\n<pre>ALTER TABLE users ADD COLUMN age INT NOT NULL DEFAULT 0;<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p><strong>4. \u4f7f\u7528 DROP COLUMN \u8bed\u53e5<\/strong><\/p>\n<p>DROP COLUMN \u8bed\u53e5\u7528\u4e8e\u4ece\u8868\u4e2d\u5220\u9664\u5b57\u6bb5\u3002\u5b83\u5c06\u5220\u9664\u8be5\u5b57\u6bb5\u53ca\u5176\u6240\u6709\u6570\u636e\u3002<\/p>\n<p><strong>\u8bed\u6cd5\uff1a<\/strong><\/p>\n<pre>ALTER TABLE table_name DROP COLUMN column_name;<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p>\u4f8b\u5982\uff0c\u4ece\u8868 users \u4e2d\u5220\u9664\u5b57\u6bb5 email\uff1a<\/p>\n<pre>ALTER TABLE users DROP COLUMN email;<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<p>\u4ee5\u4e0a\u5c31\u662f\u600e\u4e48\u4fee\u6539\u5b57\u6bb5\u5c5e\u6027\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>\u4fee\u6539 mysql \u5b57\u6bb5\u5c5e\u6027\u7684\u65b9\u6cd5\u6709\u56db\u79cd\uff1a1. \u4f7f\u7528 alter table \u8bed\u53e5\u4fee\u6539\u5b57\u6bb5\u540d\u79f0\u3001\u6570\u636e\u7c7b\u578b\u3001\u7ea6\u675f\u7b49\uff1b2. \u4f7f\u7528 change \u8bed\u53e5\u91cd\u547d\u540d\u5b57\u6bb5\u6216\u540c\u65f6\u4fee\u6539\u540d\u79f0\u548c\u5c5e\u6027\uff1b3. \u4f7f\u7528 add column \u8bed\u53e5\u6dfb\u52a0\u65b0\u5b57\u6bb5\uff1b4. \u4f7f\u7528 drop column \u8bed\u53e5\u5220\u9664\u5b57\u6bb5\u3002 \u5982\u4f55\u4fee\u6539 MySQL \u5b57\u6bb5\u5c5e\u6027 \u524d\u8a00\uff1a\u4fee\u6539 MySQL \u8868\u4e2d\u5b57\u6bb5\u7684\u5c5e\u6027\u5bf9\u4e8e\u4f18\u5316\u6570\u636e\u5e93\u7ed3\u6784\u548c\u4fdd\u6301\u6570\u636e\u5b8c\u6574\u6027\u81f3\u5173\u91cd\u8981\u3002\u672c\u6587\u5c06\u8be6\u7ec6\u4ecb\u7ecd\u4fee\u6539\u5b57\u6bb5\u5c5e\u6027\u7684\u4e0d\u540c\u65b9\u6cd5\u3002 \u4fee\u6539\u5b57\u6bb5\u5c5e\u6027\u7684\u65b9\u6cd5\uff1a 1. \u4f7f\u7528 ALTER TABLE \u8bed\u53e5 ALTER TABLE \u8bed\u53e5\u662f\u6700\u5e38\u7528\u7684\u65b9\u6cd5\u6765\u4fee\u6539\u5b57\u6bb5\u5c5e\u6027\u3002\u5b83\u5141\u8bb8\u60a8\u4fee\u6539\u5b57\u6bb5\u7684\u6570\u636e\u7c7b\u578b\u3001\u9ed8\u8ba4\u503c\u3001\u53ef\u4e3a\u7a7a\u6027\u3001\u552f\u4e00\u6027\u7ea6\u675f\u7b49\u3002 \u8bed\u6cd5\uff1a ALTER TABLE table_name MODIFY column_name data_type [constraints]; \u767b\u5f55\u540e\u590d\u5236 \u4f8b\u5982\uff0c\u5c06\u8868 users \u4e2d\u7684\u5b57\u6bb5 email \u4ece VARCHAR(255) \u4fee\u6539\u4e3a VARCHAR(500)\uff1a ALTER TABLE users MODIFY email [&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-5404","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5404","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=5404"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5404\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=5404"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=5404"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=5404"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}