{"id":96026,"date":"2024-10-20T05:59:16","date_gmt":"2024-10-19T21:59:16","guid":{"rendered":"https:\/\/server.hk\/cnblog\/96026\/"},"modified":"2024-10-20T05:59:16","modified_gmt":"2024-10-19T21:59:16","slug":"oracle%e6%95%b8%e6%93%9a%e5%ba%ab%e5%ad%97%e6%ae%b5%e5%b1%ac%e6%80%a7%e4%bf%ae%e6%94%b9","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/96026\/","title":{"rendered":"Oracle\u6578\u64da\u5eab\u5b57\u6bb5\u5c6c\u6027\u4fee\u6539"},"content":{"rendered":"<h1 id=\"oracle%e6%95%b8%e6%93%9a%e5%ba%ab%e5%ad%97%e6%ae%b5%e5%b1%ac%e6%80%a7%e4%bf%ae%e6%94%b9-EZjEOSmRRV\">Oracle\u6578\u64da\u5eab\u5b57\u6bb5\u5c6c\u6027\u4fee\u6539<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u5b57\u6bb5\u5c6c\u6027\u662f\u5f71\u97ff\u6578\u64da\u5b8c\u6574\u6027\u548c\u6027\u80fd\u7684\u91cd\u8981\u56e0\u7d20\u3002Oracle\u6578\u64da\u5eab\u4f5c\u70ba\u4e00\u500b\u5f37\u5927\u7684\u95dc\u4fc2\u578b\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u63d0\u4f9b\u4e86\u591a\u7a2e\u65b9\u6cd5\u4f86\u4fee\u6539\u5b57\u6bb5\u5c6c\u6027\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5982\u4f55\u5728Oracle\u6578\u64da\u5eab\u4e2d\u9032\u884c\u5b57\u6bb5\u5c6c\u6027\u4fee\u6539\uff0c\u5305\u62ec\u6578\u64da\u985e\u578b\u3001\u5927\u5c0f\u3001\u7d04\u675f\u7b49\u65b9\u9762\u7684\u8b8a\u66f4\u3002<\/p>\n<h2 id=\"%e5%ad%97%e6%ae%b5%e5%b1%ac%e6%80%a7%e6%a6%82%e8%bf%b0-EZjEOSmRRV\">\u5b57\u6bb5\u5c6c\u6027\u6982\u8ff0<\/h2>\n<p>\u5728Oracle\u6578\u64da\u5eab\u4e2d\uff0c\u6bcf\u500b\u5b57\u6bb5\u90fd\u6709\u5176\u7279\u5b9a\u7684\u5c6c\u6027\uff0c\u5305\u62ec\u6578\u64da\u985e\u578b\u3001\u5927\u5c0f\u3001\u9ed8\u8a8d\u503c\u3001\u7d04\u675f\u7b49\u3002\u9019\u4e9b\u5c6c\u6027\u6c7a\u5b9a\u4e86\u5b57\u6bb5\u80fd\u5920\u5b58\u5132\u7684\u6578\u64da\u985e\u578b\u53ca\u5176\u884c\u70ba\u3002\u4f8b\u5982\uff0c\u6578\u64da\u985e\u578b\u53ef\u4ee5\u662fVARCHAR2\u3001NUMBER\u3001DATE\u7b49\uff0c\u800c\u7d04\u675f\u5247\u53ef\u4ee5\u662fNOT NULL\u3001UNIQUE\u3001PRIMARY KEY\u7b49\u3002<\/p>\n<h2 id=\"%e4%bf%ae%e6%94%b9%e5%ad%97%e6%ae%b5%e5%b1%ac%e6%80%a7%e7%9a%84%e6%96%b9%e6%b3%95-EZjEOSmRRV\">\u4fee\u6539\u5b57\u6bb5\u5c6c\u6027\u7684\u65b9\u6cd5<\/h2>\n<p>\u5728Oracle\u4e2d\uff0c\u4fee\u6539\u5b57\u6bb5\u5c6c\u6027\u901a\u5e38\u4f7f\u7528ALTER TABLE\u8a9e\u53e5\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u898b\u7684\u4fee\u6539\u64cd\u4f5c\uff1a<\/p>\n<h3 id=\"1-%e4%bf%ae%e6%94%b9%e6%95%b8%e6%93%9a%e9%a1%9e%e5%9e%8b-EZjEOSmRRV\">1. \u4fee\u6539\u6578\u64da\u985e\u578b<\/h3>\n<p>\u8981\u4fee\u6539\u5b57\u6bb5\u7684\u6578\u64da\u985e\u578b\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u8a9e\u6cd5\uff1a<\/p>\n<pre><code>ALTER TABLE \u8868\u540d MODIFY \u5b57\u6bb5\u540d \u65b0\u6578\u64da\u985e\u578b;<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5982\u679c\u8981\u5c07\u540d\u70ba\u201cage\u201d\u7684\u5b57\u6bb5\u5f9eNUMBER\u985e\u578b\u4fee\u6539\u70baVARCHAR2\u985e\u578b\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u547d\u4ee4\uff1a<\/p>\n<pre><code>ALTER TABLE employees MODIFY age VARCHAR2(3);<\/code><\/pre>\n<h3 id=\"2-%e4%bf%ae%e6%94%b9%e5%ad%97%e6%ae%b5%e5%a4%a7%e5%b0%8f-EZjEOSmRRV\">2. \u4fee\u6539\u5b57\u6bb5\u5927\u5c0f<\/h3>\n<p>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u53ef\u80fd\u9700\u8981\u8abf\u6574\u5b57\u6bb5\u7684\u5927\u5c0f\u3002\u4f8b\u5982\uff0c\u5c07VARCHAR2\u5b57\u6bb5\u7684\u5927\u5c0f\u5f9e50\u6539\u70ba100\uff1a<\/p>\n<pre><code>ALTER TABLE employees MODIFY name VARCHAR2(100);<\/code><\/pre>\n<h3 id=\"3-%e6%b7%bb%e5%8a%a0%e6%88%96%e4%bf%ae%e6%94%b9%e7%b4%84%e6%9d%9f-EZjEOSmRRV\">3. \u6dfb\u52a0\u6216\u4fee\u6539\u7d04\u675f<\/h3>\n<p>\u7d04\u675f\u662f\u7528\u4f86\u78ba\u4fdd\u6578\u64da\u5b8c\u6574\u6027\u7684\u91cd\u8981\u5de5\u5177\u3002\u53ef\u4ee5\u4f7f\u7528ALTER TABLE\u8a9e\u53e5\u4f86\u6dfb\u52a0\u6216\u4fee\u6539\u7d04\u675f\u3002\u4f8b\u5982\uff0c\u6dfb\u52a0NOT NULL\u7d04\u675f\uff1a<\/p>\n<pre><code>ALTER TABLE employees MODIFY age NOT NULL;<\/code><\/pre>\n<p>\u5982\u679c\u8981\u522a\u9664\u7d04\u675f\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u8a9e\u6cd5\uff1a<\/p>\n<pre><code>ALTER TABLE \u8868\u540d DROP CONSTRAINT \u7d04\u675f\u540d;<\/code><\/pre>\n<h3 id=\"4-%e4%bf%ae%e6%94%b9%e9%bb%98%e8%aa%8d%e5%80%bc-EZjEOSmRRV\">4. \u4fee\u6539\u9ed8\u8a8d\u503c<\/h3>\n<p>\u9ed8\u8a8d\u503c\u662f\u7576\u63d2\u5165\u6578\u64da\u6642\uff0c\u5982\u679c\u672a\u63d0\u4f9b\u8a72\u5b57\u6bb5\u7684\u503c\uff0c\u5247\u81ea\u52d5\u4f7f\u7528\u7684\u503c\u3002\u8981\u4fee\u6539\u9ed8\u8a8d\u503c\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u547d\u4ee4\uff1a<\/p>\n<pre><code>ALTER TABLE \u8868\u540d MODIFY \u5b57\u6bb5\u540d DEFAULT \u65b0\u9ed8\u8a8d\u503c;<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5c07\u201cstatus\u201d\u5b57\u6bb5\u7684\u9ed8\u8a8d\u503c\u6539\u70ba\u201cactive\u201d\uff1a<\/p>\n<pre><code>ALTER TABLE employees MODIFY status DEFAULT 'active';<\/code><\/pre>\n<h2 id=\"%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-EZjEOSmRRV\">\u6ce8\u610f\u4e8b\u9805<\/h2>\n<p>\u5728\u4fee\u6539\u5b57\u6bb5\u5c6c\u6027\u6642\uff0c\u9700\u8981\u6ce8\u610f\u4ee5\u4e0b\u5e7e\u9ede\uff1a<\/p>\n<ul>\n<li>\u78ba\u4fdd\u65b0\u6578\u64da\u985e\u578b\u8207\u73fe\u6709\u6578\u64da\u517c\u5bb9\uff0c\u5426\u5247\u53ef\u80fd\u6703\u5c0e\u81f4\u6578\u64da\u4e1f\u5931\u3002<\/li>\n<li>\u5728\u4fee\u6539\u7d04\u675f\u6642\uff0c\u9700\u8003\u616e\u5230\u73fe\u6709\u6578\u64da\u662f\u5426\u7b26\u5408\u65b0\u7d04\u675f\u7684\u8981\u6c42\u3002<\/li>\n<li>\u5728\u9032\u884c\u5927\u898f\u6a21\u4fee\u6539\u4e4b\u524d\uff0c\u5efa\u8b70\u5148\u5099\u4efd\u6578\u64da\uff0c\u4ee5\u9632\u6b62\u610f\u5916\u60c5\u6cc1\u767c\u751f\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-EZjEOSmRRV\">\u7e3d\u7d50<\/h2>\n<p>\u4fee\u6539Oracle\u6578\u64da\u5eab\u4e2d\u7684\u5b57\u6bb5\u5c6c\u6027\u662f\u4e00\u9805\u91cd\u8981\u7684\u6578\u64da\u7ba1\u7406\u4efb\u52d9\uff0c\u80fd\u5920\u5e6b\u52a9\u7528\u6236\u66f4\u597d\u5730\u63a7\u5236\u6578\u64da\u7684\u7d50\u69cb\u548c\u5b8c\u6574\u6027\u3002\u901a\u904e\u4f7f\u7528ALTER TABLE\u8a9e\u53e5\uff0c\u7ba1\u7406\u54e1\u53ef\u4ee5\u9748\u6d3b\u5730\u8abf\u6574\u5b57\u6bb5\u7684\u6578\u64da\u985e\u578b\u3001\u5927\u5c0f\u3001\u7d04\u675f\u548c\u9ed8\u8a8d\u503c\u7b49\u5c6c\u6027\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u7ba1\u7406\u7684\u4f01\u696d\u4f86\u8aaa\uff0c\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\u81f3\u95dc\u91cd\u8981\u3002\u82e5\u60a8\u5c0d\u65bc<code><a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a><\/code>\u6216<code><a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a><\/code>\u6709\u8208\u8da3\uff0c\u8acb\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u4ee5\u7372\u53d6\u66f4\u591a\u4fe1\u606f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3\u5982\u4f55\u5728Oracle\u6578\u64da\u5eab\u4e2d\u4fee\u6539\u5b57\u6bb5\u5c6c\u6027\uff0c\u63d0\u5347\u6578\u64da\u7ba1\u7406\u6548\u7387\uff0c\u78ba\u4fdd\u6578\u64da\u4e00\u81f4\u6027\u8207\u5b8c\u6574\u6027\u3002<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-96026","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96026","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=96026"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96026\/revisions"}],"predecessor-version":[{"id":96027,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96026\/revisions\/96027"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=96026"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=96026"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=96026"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}