{"id":5953,"date":"2024-11-14T13:10:04","date_gmt":"2024-11-14T05:10:04","guid":{"rendered":"https:\/\/fwq.ai\/blog\/5953\/"},"modified":"2024-11-14T13:10:04","modified_gmt":"2024-11-14T05:10:04","slug":"sql%e5%a6%82%e4%bd%95%e5%9c%a8%e8%a1%a8%e4%b8%ad%e5%a2%9e%e5%8a%a0%e4%b8%80%e5%88%97","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/5953\/","title":{"rendered":"sql\u5982\u4f55\u5728\u8868\u4e2d\u589e\u52a0\u4e00\u5217"},"content":{"rendered":"

\n \u5982\u4f55\u5728 sql \u8868\u4e2d\u589e\u52a0\u4e00\u5217\uff1f\u4f7f\u7528 alter table \u8bed\u53e5\uff0c\u6307\u5b9a\u8868\u540d\u3001\u5217\u540d\u548c\u6570\u636e\u7c7b\u578b\uff1b\u53ef\u9009\u8bbe\u7f6e not null \u7ea6\u675f\u548c\u9ed8\u8ba4\u503c\uff1b\u8fd0\u884c alter table \u8bed\u53e5\u5c06\u65b0\u5217\u6dfb\u52a0\u5230\u8868\u4e2d\u3002\n<\/p><\/blockquote>\n

\"sql\u5982\u4f55\u5728\u8868\u4e2d\u589e\u52a0\u4e00\u5217\u63d2\u56fe\"<\/p>\n

\u5982\u4f55\u5728 SQL \u8868\u4e2d\u589e\u52a0\u4e00\u5217<\/strong><\/p>\n

\u524d\u8a00<\/strong><\/p>\n

\u5728 SQL \u4e2d\uff0c\u589e\u52a0\u4e00\u5217\u662f\u4e00\u4e2a\u5e38\u89c1\u64cd\u4f5c\uff0c\u53ef\u4ee5\u6269\u5c55\u8868\u5e76\u6dfb\u52a0\u989d\u5916\u4fe1\u606f\u3002\u672c\u6587\u5c06\u8be6\u7ec6\u4ecb\u7ecd\u5982\u4f55\u4f7f\u7528 SQL \u8bed\u53e5\u5728\u8868\u4e2d\u589e\u52a0\u4e00\u5217\u3002<\/p>\n

\u8bed\u6cd5<\/strong><\/p>\n

ALTER TABLE table_name ADD COLUMN column_name data_type [NOT NULL] [DEFAULT default_value];<\/pre>\n
  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
\u53c2\u6570\u8bf4\u660e<\/strong><\/p>\n
    \n
  •  table_name\uff1a<\/strong>\u9700\u8981\u6dfb\u52a0\u5217\u7684\u8868\u540d\u79f0\u3002<\/li>\n
  •  column_name\uff1a<\/strong>\u8981\u6dfb\u52a0\u7684\u65b0\u5217\u7684\u540d\u79f0\u3002<\/li>\n
  •  data_type\uff1a<\/strong>\u65b0\u5217\u7684\u6570\u636e\u7c7b\u578b\u3002<\/li>\n
  •  NOT NULL\uff1a<\/strong>\u6307\u5b9a\u65b0\u5217\u662f\u5426\u53ef\u4ee5\u5305\u542b\u7a7a\u503c\u3002\u9ed8\u8ba4\u503c\u4e3a\u5141\u8bb8\u7a7a\u503c\u3002<\/li>\n
  •  DEFAULT default_value\uff1a<\/strong>\u6307\u5b9a\u65b0\u5217\u7684\u9ed8\u8ba4\u503c\u3002\u5982\u679c\u672a\u6307\u5b9a\uff0c\u65b0\u5217\u5c06\u5305\u542b\u7a7a\u503c\u3002<\/li>\n<\/ul>\n
    \u64cd\u4f5c\u6b65\u9aa4<\/strong><\/p>\n
      \n
    1.  \u6253\u5f00\u6570\u636e\u5e93\u8fde\u63a5\uff1a<\/strong>\u4f7f\u7528 SQL \u5ba2\u6237\u7aef\u5de5\u5177\u8fde\u63a5\u5230\u6570\u636e\u5e93\u3002<\/li>\n
    2.  \u4f7f\u7528 ALTER TABLE \u8bed\u53e5\uff1a<\/strong>\u4f7f\u7528\u4e0a\u8ff0\u8bed\u6cd5\u7f16\u5199 ALTER TABLE \u8bed\u53e5\uff0c\u6307\u5b9a\u8868\u540d\u3001\u5217\u540d\u3001\u6570\u636e\u7c7b\u578b\u548c\u5176\u4ed6\u53ef\u9009\u53c2\u6570\u3002<\/li>\n
    3.  \u6267\u884c\u8bed\u53e5\uff1a<\/strong>\u8fd0\u884c ALTER TABLE \u8bed\u53e5\uff0c\u5c06\u65b0\u5217\u6dfb\u52a0\u5230\u8868\u4e2d\u3002<\/li>\n<\/ol>\n
      \u793a\u4f8b<\/strong><\/p>\n
      \u4ee5\u4e0b\u793a\u4f8b\u5c06\u5728\u540d\u4e3a “Customers” \u7684\u8868\u4e2d\u6dfb\u52a0\u540d\u4e3a “Email” \u7684\u6587\u672c\u5217\uff0c\u5e76\u8bbe\u7f6e\u9ed8\u8ba4\u503c\u4e3a “example@example.com”\uff1a<\/p>\n
      ALTER TABLE Customers ADD COLUMN Email TEXT NOT NULL DEFAULT 'example@example.com';<\/pre>\n
        \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
      \u6ce8\u610f\uff1a<\/strong><\/p>\n
        \n
      • \u786e\u4fdd\u65b0\u5217\u7684\u540d\u79f0\u5728\u8868\u4e2d\u662f\u552f\u4e00\u7684\u3002<\/li>\n
      • \u9009\u62e9\u5408\u9002\u7684\u6570\u636e\u7c7b\u578b\u4ee5\u5b58\u50a8\u65b0\u5217\u4e2d\u7684\u6570\u636e\u3002<\/li>\n
      • \u6839\u636e\u4e1a\u52a1\u9700\u6c42\u8003\u8651\u662f\u5426\u8bbe\u7f6e NOT NULL \u7ea6\u675f\u548c\u9ed8\u8ba4\u503c\u3002<\/li>\n
      • \u5728\u6267\u884c ALTER TABLE \u8bed\u53e5\u4e4b\u524d\uff0c\u5efa\u8bae\u5907\u4efd\u6570\u636e\u5e93\u4ee5\u9632\u51fa\u73b0\u610f\u5916\u60c5\u51b5\u3002<\/li>\n<\/ul>\n
        \u4ee5\u4e0a\u5c31\u662fsql\u5982\u4f55\u5728\u8868\u4e2d\u589e\u52a0\u4e00\u5217\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":"
        \u5982\u4f55\u5728 sql \u8868\u4e2d\u589e\u52a0\u4e00\u5217\uff1f\u4f7f\u7528 alter table \u8bed\u53e5\uff0c\u6307\u5b9a\u8868\u540d\u3001\u5217\u540d\u548c\u6570\u636e\u7c7b\u578b\uff1b\u53ef\u9009\u8bbe\u7f6e not null \u7ea6\u675f\u548c\u9ed8\u8ba4\u503c\uff1b\u8fd0\u884c alter table \u8bed\u53e5\u5c06\u65b0\u5217\u6dfb\u52a0\u5230\u8868\u4e2d\u3002 \u5982\u4f55\u5728 SQL \u8868\u4e2d\u589e\u52a0\u4e00\u5217 \u524d\u8a00 \u5728 SQL \u4e2d\uff0c\u589e\u52a0\u4e00\u5217\u662f\u4e00\u4e2a\u5e38\u89c1\u64cd\u4f5c\uff0c\u53ef\u4ee5\u6269\u5c55\u8868\u5e76\u6dfb\u52a0\u989d\u5916\u4fe1\u606f\u3002\u672c\u6587\u5c06\u8be6\u7ec6\u4ecb\u7ecd\u5982\u4f55\u4f7f\u7528 SQL \u8bed\u53e5\u5728\u8868\u4e2d\u589e\u52a0\u4e00\u5217\u3002 \u8bed\u6cd5 ALTER TABLE table_name ADD COLUMN column_name data_type [NOT NULL] [DEFAULT default_value]; \u767b\u5f55\u540e\u590d\u5236 \u53c2\u6570\u8bf4\u660e table_name\uff1a\u9700\u8981\u6dfb\u52a0\u5217\u7684\u8868\u540d\u79f0\u3002 column_name\uff1a\u8981\u6dfb\u52a0\u7684\u65b0\u5217\u7684\u540d\u79f0\u3002 data_type\uff1a\u65b0\u5217\u7684\u6570\u636e\u7c7b\u578b\u3002 NOT NULL\uff1a\u6307\u5b9a\u65b0\u5217\u662f\u5426\u53ef\u4ee5\u5305\u542b\u7a7a\u503c\u3002\u9ed8\u8ba4\u503c\u4e3a\u5141\u8bb8\u7a7a\u503c\u3002 DEFAULT default_value\uff1a\u6307\u5b9a\u65b0\u5217\u7684\u9ed8\u8ba4\u503c\u3002\u5982\u679c\u672a\u6307\u5b9a\uff0c\u65b0\u5217\u5c06\u5305\u542b\u7a7a\u503c\u3002 \u64cd\u4f5c\u6b65\u9aa4 \u6253\u5f00\u6570\u636e\u5e93\u8fde\u63a5\uff1a\u4f7f\u7528 SQL \u5ba2\u6237\u7aef\u5de5\u5177\u8fde\u63a5\u5230\u6570\u636e\u5e93\u3002 \u4f7f\u7528 ALTER TABLE \u8bed\u53e5\uff1a\u4f7f\u7528\u4e0a\u8ff0\u8bed\u6cd5\u7f16\u5199 ALTER TABLE \u8bed\u53e5\uff0c\u6307\u5b9a\u8868\u540d\u3001\u5217\u540d\u3001\u6570\u636e\u7c7b\u578b\u548c\u5176\u4ed6\u53ef\u9009\u53c2\u6570\u3002 \u6267\u884c\u8bed\u53e5\uff1a\u8fd0\u884c ALTER […]<\/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-5953","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5953","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=5953"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5953\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=5953"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=5953"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=5953"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}