{"id":5047,"date":"2024-11-14T08:25:01","date_gmt":"2024-11-14T00:25:01","guid":{"rendered":"https:\/\/fwq.ai\/blog\/5047\/"},"modified":"2024-11-14T08:25:01","modified_gmt":"2024-11-14T00:25:01","slug":"oracle-decode%e5%87%bd%e6%95%b0%e6%80%8e%e4%b9%88%e7%94%a8","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/5047\/","title":{"rendered":"oracle decode\u51fd\u6570\u600e\u4e48\u7528"},"content":{"rendered":"

\n oracle decode \u51fd\u6570\u662f\u4e00\u4e2a\u6761\u4ef6\u8bed\u53e5\uff0c\u7528\u4e8e\u6839\u636e\u6307\u5b9a\u6761\u4ef6\u8fd4\u56de\u4e0d\u540c\u7684\u503c\u3002\u8bed\u6cd5\u4e3a decode(expression, value1, result1, …, default_result)\uff0c\u5176\u4e2d expression \u662f\u8981\u8bc4\u4f30\u7684\u8868\u8fbe\u5f0f\uff0cvalue1 \u662f\u7b2c\u4e00\u4e2a\u8981\u6bd4\u8f83\u7684\u503c\uff0cresult1 \u662f\u5f53 expression \u7b49\u4e8e\u8be5\u503c\u65f6\u8fd4\u56de\u7684\u7ed3\u679c\uff0c\u540e\u9762\u6210\u5bf9\u51fa\u73b0\u7684\u503c\u548c\u7ed3\u679c\uff0cdefault_result \u662f\u4e0d\u5339\u914d\u4efb\u4f55\u503c\u65f6\u7684\u8fd4\u56de\u503c\u3002\n<\/p><\/blockquote>\n

\"oracle<\/p>\n

Oracle DECODE \u51fd\u6570\u7528\u6cd5<\/strong><\/p>\n

Oracle DECODE \u51fd\u6570\u662f\u4e00\u79cd\u7528\u4e8e\u5728\u6307\u5b9a\u6761\u4ef6\u4e0b\u8fd4\u56de\u4e0d\u540c\u503c\u7684\u6761\u4ef6\u8bed\u53e5\u3002\u8bed\u6cd5\u5982\u4e0b\uff1a<\/p>\n

DECODE(expression, value1, result1, value2, result2, ..., default_result)<\/pre>\n
 \u767b\u5f55\u540e\u590d\u5236 <\/p>\n
\u4f7f\u7528\u65b9\u6cd5\uff1a<\/strong><\/p>\n
DECODE \u51fd\u6570\u6709\u4e24\u4e2a\u5fc5\u9700\u7684\u53c2\u6570\uff1a<\/p>\n
    \n
  •  expression\uff1a<\/strong>\u8981\u8bc4\u4f30\u7684\u8868\u8fbe\u5f0f<\/li>\n
  •  value1\uff1a<\/strong>\u8981\u6bd4\u8f83\u7684\u7b2c\u4e00\u4e2a\u503c<\/li>\n<\/ul>\n
    \u968f\u540e\u7684\u53c2\u6570\u6309\u7167\u6210\u5bf9\u51fa\u73b0\uff0c\u7b2c\u4e00\u4e2a\u53c2\u6570\u662f\u503c\uff0c\u7b2c\u4e8c\u4e2a\u53c2\u6570\u662f\u5f53 expression \u7b49\u4e8e\u8be5\u503c\u65f6\u8fd4\u56de\u7684\u7ed3\u679c\u3002<\/p>\n
    \u5982\u679c expression \u4e0e\u4efb\u4f55\u7ed9\u5b9a\u7684\u503c\u90fd\u4e0d\u5339\u914d\uff0c\u5219\u8fd4\u56de default_result\u3002<\/p>\n
    \u793a\u4f8b\uff1a<\/strong><\/p>\n
    \u5047\u8bbe\u6709\u4e00\u5f20\u5305\u542b\u4ee5\u4e0b\u5217\u7684 “T\u6064” \u8868\uff1a<\/p>\n\n\n\n\n\n\n\n
    \u5c3a\u5bf8<\/th>\n\u989c\u8272<\/th>\n\u6570\u91cf<\/th>\n<\/tr>\n<\/thead>\n
    S<\/td>\n\u7ea2<\/td>\n20<\/td>\n<\/tr>\n
    M<\/td>\n\u7eff<\/td>\n30<\/td>\n<\/tr>\n
    L<\/td>\n\u84dd<\/td>\n40<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    \u8981\u67e5\u8be2\u7ea2\u8272 T \u6064\u7684\u5e93\u5b58\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b DECODE \u51fd\u6570\uff1a<\/p>\n
    SELECT SUM(\u6570\u91cf)\nFROM T\u6064\nWHERE DECODE(\u989c\u8272, '\u7ea2', \u6570\u91cf, NULL) IS NOT NULL;<\/pre>\n
     \u767b\u5f55\u540e\u590d\u5236 <\/p>\n
    \u5728\u8fd9\u4e2a\u793a\u4f8b\u4e2d\uff0cexpression \u662f “\u989c\u8272” \u5217\uff0cvalue1 \u662f ‘\u7ea2’\uff0cresult1 \u662f “\u6570\u91cf” \u5217\uff0cdefault_result \u4e3a NULL\u3002\u51fd\u6570\u5c06 “\u989c\u8272” \u4e0e ‘\u7ea2’ \u8fdb\u884c\u6bd4\u8f83\uff0c\u5e76\u8fd4\u56de “\u6570\u91cf” \u503c\u3002\u56e0\u4e3a\u6ca1\u6709\u5176\u4ed6\u503c\u5339\u914d\uff0c\u6240\u4ee5 NULL \u503c\u4f1a\u88ab\u5ffd\u7565\u3002\u7ed3\u679c\u5c06\u662f\u7ea2\u8272 T \u6064\u7684\u5e93\u5b58\u6570\u91cf\u3002<\/p>\n
    \u5176\u4ed6\u7528\u6cd5\uff1a<\/strong><\/p>\n
    DECODE \u51fd\u6570\u8fd8\u53ef\u4ee5\u7528\u4e8e\uff1a<\/p>\n
      \n
    • \u8f6c\u6362\u503c\uff0c\u4f8b\u5982\u5c06\u6570\u5b57\u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32<\/li>\n
    • \u6839\u636e\u6761\u4ef6\u8bbe\u7f6e\u6807\u5fd7<\/li>\n
    • \u66ff\u6362\u7f3a\u5931\u503c<\/li>\n
    • \u5d4c\u5957\u591a\u4e2a\u6761\u4ef6\u8bed\u53e5<\/li>\n<\/ul>\n
      \u4ee5\u4e0a\u5c31\u662f decode\u51fd\u6570\u600e\u4e48\u7528\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":"
      oracle decode \u51fd\u6570\u662f\u4e00\u4e2a\u6761\u4ef6\u8bed\u53e5\uff0c\u7528\u4e8e\u6839\u636e\u6307\u5b9a\u6761\u4ef6\u8fd4\u56de\u4e0d\u540c\u7684\u503c\u3002\u8bed\u6cd5\u4e3a decode(expression, value1, result1, …, default_result)\uff0c\u5176\u4e2d expression \u662f\u8981\u8bc4\u4f30\u7684\u8868\u8fbe\u5f0f\uff0cvalue1 \u662f\u7b2c\u4e00\u4e2a\u8981\u6bd4\u8f83\u7684\u503c\uff0cresult1 \u662f\u5f53 expression \u7b49\u4e8e\u8be5\u503c\u65f6\u8fd4\u56de\u7684\u7ed3\u679c\uff0c\u540e\u9762\u6210\u5bf9\u51fa\u73b0\u7684\u503c\u548c\u7ed3\u679c\uff0cdefault_result \u662f\u4e0d\u5339\u914d\u4efb\u4f55\u503c\u65f6\u7684\u8fd4\u56de\u503c\u3002 Oracle DECODE \u51fd\u6570\u7528\u6cd5 Oracle DECODE \u51fd\u6570\u662f\u4e00\u79cd\u7528\u4e8e\u5728\u6307\u5b9a\u6761\u4ef6\u4e0b\u8fd4\u56de\u4e0d\u540c\u503c\u7684\u6761\u4ef6\u8bed\u53e5\u3002\u8bed\u6cd5\u5982\u4e0b\uff1a DECODE(expression, value1, result1, value2, result2, …, default_result) \u767b\u5f55\u540e\u590d\u5236 \u4f7f\u7528\u65b9\u6cd5\uff1a DECODE \u51fd\u6570\u6709\u4e24\u4e2a\u5fc5\u9700\u7684\u53c2\u6570\uff1a expression\uff1a\u8981\u8bc4\u4f30\u7684\u8868\u8fbe\u5f0f value1\uff1a\u8981\u6bd4\u8f83\u7684\u7b2c\u4e00\u4e2a\u503c \u968f\u540e\u7684\u53c2\u6570\u6309\u7167\u6210\u5bf9\u51fa\u73b0\uff0c\u7b2c\u4e00\u4e2a\u53c2\u6570\u662f\u503c\uff0c\u7b2c\u4e8c\u4e2a\u53c2\u6570\u662f\u5f53 expression \u7b49\u4e8e\u8be5\u503c\u65f6\u8fd4\u56de\u7684\u7ed3\u679c\u3002 \u5982\u679c expression \u4e0e\u4efb\u4f55\u7ed9\u5b9a\u7684\u503c\u90fd\u4e0d\u5339\u914d\uff0c\u5219\u8fd4\u56de default_result\u3002 \u793a\u4f8b\uff1a \u5047\u8bbe\u6709\u4e00\u5f20\u5305\u542b\u4ee5\u4e0b\u5217\u7684 “T\u6064” \u8868\uff1a \u5c3a\u5bf8 \u989c\u8272 \u6570\u91cf S \u7ea2 20 M \u7eff 30 L […]<\/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-5047","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5047","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=5047"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5047\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=5047"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=5047"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=5047"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}