{"id":1436,"date":"2006-07-26T17:28:41","date_gmt":"2006-07-26T09:28:41","guid":{"rendered":"http:\/\/ihower.idv.tw\/blog\/archives\/1436"},"modified":"2008-09-29T01:13:53","modified_gmt":"2008-09-28T17:13:53","slug":"rails-%e7%9a%84-migrations","status":"publish","type":"post","link":"https:\/\/ihower.tw\/blog\/1436-rails-%e7%9a%84-migrations","title":{"rendered":"Rails \u7684  Migrations"},"content":{"rendered":"<p>Migrations \u8b93\u4f60\u7528 Ruby \u8a9e\u6cd5\u4f86\u5b9a\u7fa9\u8cc7\u6599\u5eab\u7d50\u69cb\u3002\u9019\u6709\u4ec0\u9ebc\u597d\u8655? \u9019\u53ef\u4ee5\u8b93\u8cc7\u6599\u5eab\u7d50\u69cb\u4e5f\u53ef\u4ee5\u50cf code \u4e00\u6a23\u505a\u7248\u672c\u63a7\u5236\uff0c\u591a\u4eba\u958b\u767c\u6642\u53ef\u4ee5\u66f4\u5bb9\u6613\u66f4\u65b0\u8cc7\u6599\u5eab\u7248\u672c\uff0c\u7522\u54c1\u66f4\u5bb9\u6613\u5347\u7d1a\uff0c\u4e0d\u540c\u8cc7\u6599\u5eab\u4e5f\u66f4\u5bb9\u6613\u505a\u540c\u6b65\u3002\u9019\u4e9b\u90fd\u53ea\u8981\u6253 <font face=\"Courier New\">rake migrate \u5c31\u53ef\u4ee5\u5b8c\u6210\u3002<\/font><\/p>\n<p><font face=\"Courier New\">\u53c3\u8003\u8cc7\u6599 :<\/font><\/p>\n<ul>\n<li><font face=\"Verdana\">Wiki: <a href=\"http:\/\/wiki.rubyonrails.org\/rails\/pages\/ActiveRecordMigration\">ActiveRecordMigration<\/a><\/font><\/li>\n<li><font face=\"Verdana\">API: <a href=\"http:\/\/api.rubyonrails.org\/classes\/ActiveRecord\/Migration.html\">ActiveRecord::Migration<\/a><\/font><\/li>\n<li><a href=\"http:\/\/pityathome.com\/blog\/articles\/2006\/03\/01\/migration-in-rails\">Aluminum Oxide<\/a><\/li>\n<\/ul>\n<p>\u7c21\u6613\u7bc4\u4f8b :<!--more--><\/p>\n<p><strong>1.\u65b0\u5efa Migration<\/strong><\/p>\n<blockquote><p>ruby script\/generate migration add_a_new_table<\/p><\/blockquote>\n<p>\u9019\u6703\u5efa\u7acb <font face=\"Courier New\">db\/migrate\/001_add_a_new_table.rb \u9019\u500b\u6a94\u6848 ( \u6ce8\u610f <\/font><font face=\"Verdana\">add_a_new_table \u76f4\u63a5\u5c0d\u61c9\u5230\u8cc7\u6599\u8868 AddANewTable )<\/font><\/p>\n<p><strong><font face=\"Courier New\">2.\u7de8\u8f2f<\/font><font face=\"Verdana\"> Migration<\/font><\/strong><\/p>\n<p>self.up \u6703\u5728\u5efa\u7acb\u65b0\u7248\u672c\u6642\u57f7\u884c\uff0cself.down \u5247\u662f\u7248\u672c\u56de\u5fa9\u3002<\/p>\n<blockquote><p>\u00a0 class AddANewTable &lt; ActiveRecord::Migration<br \/>\n\u00a0\u00a0\u00a0 def self.up<br \/>\n\u00a0\u00a0\u00a0\u00a0\u00a0 create_table :users do |table|<br \/>\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 table.column :name, :string<br \/>\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 table.column :login,\u00a0 :string, :null =&gt; false<br \/>\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 # This column will contain an MD5 hash.<br \/>\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 table.column :password, :string, :limit =&gt; 32, :null =&gt; false<br \/>\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 table.column :email, :string<br \/>\n\u00a0\u00a0\u00a0\u00a0\u00a0 end<br \/>\n\u00a0\u00a0\u00a0 end<\/p>\n<p>\u00a0\u00a0\u00a0 def self.down<br \/>\n\u00a0\u00a0\u00a0\u00a0\u00a0 drop_table :users<br \/>\n\u00a0\u00a0\u00a0 end<br \/>\n\u00a0 end<\/p><\/blockquote>\n<p>\u53ef\u7528\u7684 Type \u6709<strong> integer, float, datetime, date, timestamp, time, text, string, binary,\u00a0boolean<\/strong>\u3002<\/p>\n<p>\u53ef\u7528\u7684\u6b04\u4f4d options \u6709 <strong>limit<\/strong> ( :limit =&gt; \u201c50\u201d ) <strong>default<\/strong> (:default =&gt; \u201cblah\u201d ) <strong>null<\/strong> (:null =&gt; false implies <span class=\"caps\">NOT NULL<\/span>)<\/p>\n<p><strong>3. \u57f7\u884c Migration<\/strong><\/p>\n<blockquote><p>rake migrate<\/p><\/blockquote>\n<p>\u00a0\u7279\u5b9a\u7248\u672c\u5247\u662f rake migrate VERSION=17<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Migrations \u8b93\u4f60\u7528 Ruby \u8a9e\u6cd5\u4f86\u5b9a\u7fa9\u8cc7\u6599\u5eab\u7d50\u69cb\u3002\u9019\u6709\u4ec0\u9ebc\u597d\u8655? \u9019\u53ef\u4ee5\u8b93\u8cc7\u6599\u5eab\u7d50\u69cb\u4e5f\u53ef\u4ee5\u50cf co &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/ihower.tw\/blog\/1436-rails-%e7%9a%84-migrations\" class=\"more-link\">\u95b1\u8b80\u5168\u6587<span class=\"screen-reader-text\">\u3008Rails \u7684  Migrations\u3009<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[5,53],"tags":[],"class_list":["post-1436","post","type-post","status-publish","format-standard","hentry","category-programming","category-rails","entry"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p1q6tG-na","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/ihower.tw\/blog\/wp-json\/wp\/v2\/posts\/1436","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ihower.tw\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ihower.tw\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ihower.tw\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ihower.tw\/blog\/wp-json\/wp\/v2\/comments?post=1436"}],"version-history":[{"count":0,"href":"https:\/\/ihower.tw\/blog\/wp-json\/wp\/v2\/posts\/1436\/revisions"}],"wp:attachment":[{"href":"https:\/\/ihower.tw\/blog\/wp-json\/wp\/v2\/media?parent=1436"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ihower.tw\/blog\/wp-json\/wp\/v2\/categories?post=1436"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ihower.tw\/blog\/wp-json\/wp\/v2\/tags?post=1436"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}