{"id":5660,"date":"2024-11-14T10:19:06","date_gmt":"2024-11-14T02:19:06","guid":{"rendered":"https:\/\/fwq.ai\/blog\/5660\/"},"modified":"2024-11-14T10:19:06","modified_gmt":"2024-11-14T02:19:06","slug":"sql%e6%80%8e%e4%b9%88%e5%a2%9e%e5%8a%a0%e5%ad%97%e6%ae%b5","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/5660\/","title":{"rendered":"sql\u600e\u4e48\u589e\u52a0\u5b57\u6bb5"},"content":{"rendered":"

\n \u5728 sql \u4e2d\uff0c\u4f7f\u7528 alter table \u8bed\u53e5\u53ef\u4ee5\u589e\u52a0\u8868\u4e2d\u7684\u5b57\u6bb5\u3002\u6b65\u9aa4\u5982\u4e0b\uff1a\u4f7f\u7528 alter table \u8bed\u53e5\uff0c\u5176\u4e2d\u6307\u5b9a\u8868\u540d\u3001\u65b0\u5b57\u6bb5\u540d\u548c\u6570\u636e\u7c7b\u578b\u3002\u6267\u884c\u8bed\u53e5\u4ee5\u521b\u5efa\u65b0\u5b57\u6bb5\u3002\u786e\u4fdd\u65b0\u5b57\u6bb5\u540d\u552f\u4e00\uff0c\u5982\u679c\u672a\u6307\u5b9a\u6570\u636e\u7c7b\u578b\u5219\u9ed8\u8ba4\u4e3a varchar(255)\u3002\u53ef\u9009\uff1a\u4f7f\u7528\u7ea6\u675f\uff08\u5982 not null\u3001unique\uff09\u6765\u5f3a\u5236\u5b57\u6bb5\u503c\u548c\u9632\u6b62\u91cd\u590d\u503c\u3002\n<\/p><\/blockquote>\n

\"sql\u600e\u4e48\u589e\u52a0\u5b57\u6bb5\u63d2\u56fe\"<\/p>\n

\u5982\u4f55\u4f7f\u7528 SQL \u589e\u52a0\u8868\u4e2d\u7684\u5b57\u6bb5<\/strong><\/p>\n

\u5728 SQL \u4e2d\u589e\u52a0\u8868\u4e2d\u7684\u5b57\u6bb5\u662f\u4e00\u4e2a\u7b80\u5355\u7684\u8fc7\u7a0b\uff0c\u53ef\u4ee5\u901a\u8fc7\u4f7f\u7528 ALTER TABLE \u8bed\u53e5\u6765\u5b9e\u73b0\u3002\u4ee5\u4e0b\u662f\u5982\u4f55\u6267\u884c\u6b64\u64cd\u4f5c\u7684\u8be6\u7ec6\u6307\u5357\uff1a<\/p>\n

\u8bed\u6cd5\uff1a<\/strong><\/p>\n

ALTER TABLE table_name ADD column_name data_type [constraints];<\/pre>\n
  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
\u53c2\u6570\uff1a<\/strong><\/p>\n
    \n
  • table_name\uff1a\u8981\u6dfb\u52a0\u5b57\u6bb5\u7684\u8868\u7684\u540d\u79f0\u3002<\/li>\n
  • column_name\uff1a\u8981\u6dfb\u52a0\u7684\u65b0\u5b57\u6bb5\u7684\u540d\u79f0\u3002<\/li>\n
  • data_type\uff1a\u65b0\u5b57\u6bb5\u7684\u6570\u636e\u7c7b\u578b\uff08\u5982 INT\u3001VARCHAR\u3001DATE\uff09\u3002<\/li>\n
  • constraints\uff08\u53ef\u9009\uff09\uff1a\u53ef\u4ee5\u5e94\u7528\u4e8e\u65b0\u5b57\u6bb5\u7684\u4efb\u4f55\u7ea6\u675f\uff08\u5982 NOT NULL\u3001UNIQUE\u3001DEFAULT\uff09\u3002<\/li>\n<\/ul>\n
    \u6b65\u9aa4\uff1a<\/strong><\/p>\n
      \n
    1.  \u8fde\u63a5\u5230\u6570\u636e\u5e93\uff1a<\/strong>\u4f7f\u7528 SQL \u5ba2\u6237\u7aef\u6216\u5de5\u5177\u8fde\u63a5\u5230\u8981\u7f16\u8f91\u7684\u6570\u636e\u5e93\u3002<\/li>\n
    2.  \u4f7f\u7528 ALTER TABLE \u8bed\u53e5\uff1a<\/strong>\u952e\u5165\u4ee5\u4e0b\u8bed\u53e5\uff0c\u5176\u4e2d\u66ff\u6362 table_name\u3001column_name \u548c data_type \u4e3a\u4f60\u7684\u5b9e\u9645\u503c\uff1a<\/li>\n<\/ol>\n
      ALTER TABLE table_name ADD column_name data_type;<\/pre>\n
        \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
        \n
      1.  \u8fd0\u884c\u8bed\u53e5\uff1a<\/strong>\u6267\u884c\u8be5\u8bed\u53e5\u4ee5\u521b\u5efa\u65b0\u5b57\u6bb5\u3002<\/li>\n<\/ol>\n
        \u793a\u4f8b\uff1a<\/strong><\/p>\n
        \u4f8b\u5982\uff0c\u8981\u5411\u540d\u4e3a customers \u7684\u8868\u4e2d\u6dfb\u52a0\u4e00\u4e2a\u540d\u4e3a email \u7684 VARCHAR \u5b57\u6bb5\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u8bed\u53e5\uff1a<\/p>\n
        ALTER TABLE customers ADD email VARCHAR(255);<\/pre>\n
          \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
        \u8fd0\u884c\u6b64\u8bed\u53e5\u540e\uff0cemail \u5b57\u6bb5\u5c06\u88ab\u6dfb\u52a0\u5230 customers \u8868\u4e2d\uff0c\u5176\u6570\u636e\u7c7b\u578b\u4e3a VARCHAR(255)\u3002<\/p>\n
        \u63d0\u793a\uff1a<\/strong><\/p>\n
          \n
        • \u786e\u4fdd\u65b0\u5b57\u6bb5\u540d\u79f0\u5728\u8868\u4e2d\u662f\u552f\u4e00\u7684\u3002<\/li>\n
        • \u5982\u679c\u4e0d\u6307\u5b9a\u6570\u636e\u7c7b\u578b\uff0c\u5219\u9ed8\u8ba4\u4e3a VARCHAR(255)\u3002<\/li>\n
        • \u53ef\u4ee5\u4f7f\u7528 NOT NULL \u7ea6\u675f\u6765\u5f3a\u5236\u5b57\u6bb5\u5305\u542b\u503c\u3002<\/li>\n
        • \u53ef\u4ee5\u4f7f\u7528 UNIQUE \u7ea6\u675f\u6765\u9632\u6b62\u5b57\u6bb5\u4e2d\u51fa\u73b0\u91cd\u590d\u503c\u3002<\/li>\n<\/ul>\n
          \u4ee5\u4e0a\u5c31\u662fsql\u600e\u4e48\u589e\u52a0\u5b57\u6bb5\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":"
          \u5728 sql \u4e2d\uff0c\u4f7f\u7528 alter table \u8bed\u53e5\u53ef\u4ee5\u589e\u52a0\u8868\u4e2d\u7684\u5b57\u6bb5\u3002\u6b65\u9aa4\u5982\u4e0b\uff1a\u4f7f\u7528 alter table \u8bed\u53e5\uff0c\u5176\u4e2d\u6307\u5b9a\u8868\u540d\u3001\u65b0\u5b57\u6bb5\u540d\u548c\u6570\u636e\u7c7b\u578b\u3002\u6267\u884c\u8bed\u53e5\u4ee5\u521b\u5efa\u65b0\u5b57\u6bb5\u3002\u786e\u4fdd\u65b0\u5b57\u6bb5\u540d\u552f\u4e00\uff0c\u5982\u679c\u672a\u6307\u5b9a\u6570\u636e\u7c7b\u578b\u5219\u9ed8\u8ba4\u4e3a varchar(255)\u3002\u53ef\u9009\uff1a\u4f7f\u7528\u7ea6\u675f\uff08\u5982 not null\u3001unique\uff09\u6765\u5f3a\u5236\u5b57\u6bb5\u503c\u548c\u9632\u6b62\u91cd\u590d\u503c\u3002 \u5982\u4f55\u4f7f\u7528 SQL \u589e\u52a0\u8868\u4e2d\u7684\u5b57\u6bb5 \u5728 SQL \u4e2d\u589e\u52a0\u8868\u4e2d\u7684\u5b57\u6bb5\u662f\u4e00\u4e2a\u7b80\u5355\u7684\u8fc7\u7a0b\uff0c\u53ef\u4ee5\u901a\u8fc7\u4f7f\u7528 ALTER TABLE \u8bed\u53e5\u6765\u5b9e\u73b0\u3002\u4ee5\u4e0b\u662f\u5982\u4f55\u6267\u884c\u6b64\u64cd\u4f5c\u7684\u8be6\u7ec6\u6307\u5357\uff1a \u8bed\u6cd5\uff1a ALTER TABLE table_name ADD column_name data_type [constraints]; \u767b\u5f55\u540e\u590d\u5236 \u53c2\u6570\uff1a table_name\uff1a\u8981\u6dfb\u52a0\u5b57\u6bb5\u7684\u8868\u7684\u540d\u79f0\u3002 column_name\uff1a\u8981\u6dfb\u52a0\u7684\u65b0\u5b57\u6bb5\u7684\u540d\u79f0\u3002 data_type\uff1a\u65b0\u5b57\u6bb5\u7684\u6570\u636e\u7c7b\u578b\uff08\u5982 INT\u3001VARCHAR\u3001DATE\uff09\u3002 constraints\uff08\u53ef\u9009\uff09\uff1a\u53ef\u4ee5\u5e94\u7528\u4e8e\u65b0\u5b57\u6bb5\u7684\u4efb\u4f55\u7ea6\u675f\uff08\u5982 NOT NULL\u3001UNIQUE\u3001DEFAULT\uff09\u3002 \u6b65\u9aa4\uff1a \u8fde\u63a5\u5230\u6570\u636e\u5e93\uff1a\u4f7f\u7528 SQL \u5ba2\u6237\u7aef\u6216\u5de5\u5177\u8fde\u63a5\u5230\u8981\u7f16\u8f91\u7684\u6570\u636e\u5e93\u3002 \u4f7f\u7528 ALTER TABLE \u8bed\u53e5\uff1a\u952e\u5165\u4ee5\u4e0b\u8bed\u53e5\uff0c\u5176\u4e2d\u66ff\u6362 table_name\u3001column_name \u548c data_type \u4e3a\u4f60\u7684\u5b9e\u9645\u503c\uff1a ALTER TABLE table_name ADD column_name […]<\/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-5660","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5660","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=5660"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5660\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=5660"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=5660"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=5660"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}