{"id":5709,"date":"2024-11-14T09:33:45","date_gmt":"2024-11-14T01:33:45","guid":{"rendered":"https:\/\/fwq.ai\/blog\/5709\/"},"modified":"2024-11-14T09:33:45","modified_gmt":"2024-11-14T01:33:45","slug":"sql%e6%b8%b8%e6%a0%87%e6%80%8e%e4%b9%88%e5%86%99","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/5709\/","title":{"rendered":"sql\u6e38\u6807\u600e\u4e48\u5199"},"content":{"rendered":"

\n sql\u6e38\u6807\u662f\u4e00\u79cd\u7528\u4e8e\u7ba1\u7406\u548c\u904d\u5386\u7ed3\u679c\u96c6\u7684\u7ed3\u6784\uff0c\u5b83\u5141\u8bb8\u5e94\u7528\u7a0b\u5e8f\u5728\u7ed3\u679c\u96c6\u4e2d\u5411\u4e0a\u3001\u5411\u4e0b\u6216\u968f\u673a\u79fb\u52a8\u5e76\u68c0\u7d22\u6570\u636e\u3002\u8981\u5199sql\u6e38\u6807\uff0c\u9700\u8981\u8fdb\u884c\u4ee5\u4e0b\u6b65\u9aa4\uff1a1. \u58f0\u660e\u6e38\u6807\uff1b2. \u6253\u5f00\u6e38\u6807\uff1b3. \u83b7\u53d6\u6570\u636e\uff1b4. \u5173\u95ed\u6e38\u6807\u3002\n<\/p><\/blockquote>\n

\"sql\u6e38\u6807\u600e\u4e48\u5199\u63d2\u56fe\"<\/p>\n

SQL \u6e38\u6807<\/strong><\/p>\n

\u4ec0\u4e48\u662f SQL \u6e38\u6807\uff1f<\/strong><\/p>\n

SQL \u6e38\u6807\u662f\u4e00\u4e2a\u7528\u4e8e\u7ba1\u7406\u548c\u904d\u5386\u7ed3\u679c\u96c6\u7684\u7ed3\u6784\u3002\u5b83\u5141\u8bb8\u5e94\u7528\u7a0b\u5e8f\u4ece\u7ed3\u679c\u96c6\u4e2d\u5411\u4e0a\u3001\u5411\u4e0b\u6216\u968f\u673a\u79fb\u52a8\u5e76\u68c0\u7d22\u6570\u636e\u3002<\/p>\n

\u5982\u4f55\u5199 SQL \u6e38\u6807\uff1f<\/strong><\/p>\n

\u58f0\u660e\u6e38\u6807\uff1a<\/strong><\/p>\n

DECLARE cursor_name CURSOR FOR select_statement;<\/pre>\n
  \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
    \n
  • cursor_name\uff1a\u8981\u521b\u5efa\u7684\u6e38\u6807\u7684\u540d\u79f0\u3002<\/li>\n
  • select_statement\uff1a\u68c0\u7d22\u6570\u636e\u7684 SQL \u67e5\u8be2\u3002<\/li>\n<\/ul>\n
    \u6253\u5f00\u6e38\u6807\uff1a<\/strong><\/p>\n
    OPEN cursor_name;<\/pre>\n
      \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
    \u83b7\u53d6\u6570\u636e\uff1a<\/strong><\/p>\n
    FETCH [NEXT | PRIOR | FIRST | LAST] FROM cursor_name INTO @variable1, @variable2, ...;<\/pre>\n
      \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
      \n
    • [NEXT | PRIOR | FIRST | LAST]\uff1a\u6307\u5b9a\u79fb\u52a8\u65b9\u5411\u3002<\/li>\n
    • @variable1, @variable2, …\uff1a\u5c06\u6570\u636e\u68c0\u7d22\u5230\u6307\u5b9a\u7684\u53d8\u91cf\u4e2d\u3002<\/li>\n<\/ul>\n
      \u5173\u95ed\u6e38\u6807\uff1a<\/strong><\/p>\n
      CLOSE cursor_name;<\/pre>\n
        \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
      \u793a\u4f8b\uff1a<\/strong><\/p>\n
      -- \u58f0\u660e\u6e38\u6807\u4ee5\u83b7\u53d6\u5458\u5de5\u8868\u4e2d\u7684\u6240\u6709\u8bb0\u5f55\nDECLARE employee_cursor CURSOR FOR\n  SELECT *\n  FROM employees;\n\n-- \u6253\u5f00\u6e38\u6807\nOPEN employee_cursor;\n\n-- \u9010\u884c\u83b7\u53d6\u6570\u636e\nFETCH NEXT FROM employee_cursor\n  INTO @employee_id, @first_name, @last_name;\n\n-- \u5904\u7406\u6570\u636e\n\n-- \u5173\u95ed\u6e38\u6807\nCLOSE employee_cursor;<\/pre>\n
        \u767b\u5f55\u540e\u590d\u5236   <\/p>\n
      \u4ee5\u4e0a\u5c31\u662fsql\u6e38\u6807\u600e\u4e48\u5199\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":"
      sql\u6e38\u6807\u662f\u4e00\u79cd\u7528\u4e8e\u7ba1\u7406\u548c\u904d\u5386\u7ed3\u679c\u96c6\u7684\u7ed3\u6784\uff0c\u5b83\u5141\u8bb8\u5e94\u7528\u7a0b\u5e8f\u5728\u7ed3\u679c\u96c6\u4e2d\u5411\u4e0a\u3001\u5411\u4e0b\u6216\u968f\u673a\u79fb\u52a8\u5e76\u68c0\u7d22\u6570\u636e\u3002\u8981\u5199sql\u6e38\u6807\uff0c\u9700\u8981\u8fdb\u884c\u4ee5\u4e0b\u6b65\u9aa4\uff1a1. \u58f0\u660e\u6e38\u6807\uff1b2. \u6253\u5f00\u6e38\u6807\uff1b3. \u83b7\u53d6\u6570\u636e\uff1b4. \u5173\u95ed\u6e38\u6807\u3002 SQL \u6e38\u6807 \u4ec0\u4e48\u662f SQL \u6e38\u6807\uff1f SQL \u6e38\u6807\u662f\u4e00\u4e2a\u7528\u4e8e\u7ba1\u7406\u548c\u904d\u5386\u7ed3\u679c\u96c6\u7684\u7ed3\u6784\u3002\u5b83\u5141\u8bb8\u5e94\u7528\u7a0b\u5e8f\u4ece\u7ed3\u679c\u96c6\u4e2d\u5411\u4e0a\u3001\u5411\u4e0b\u6216\u968f\u673a\u79fb\u52a8\u5e76\u68c0\u7d22\u6570\u636e\u3002 \u5982\u4f55\u5199 SQL \u6e38\u6807\uff1f \u58f0\u660e\u6e38\u6807\uff1a DECLARE cursor_name CURSOR FOR select_statement; \u767b\u5f55\u540e\u590d\u5236 cursor_name\uff1a\u8981\u521b\u5efa\u7684\u6e38\u6807\u7684\u540d\u79f0\u3002 select_statement\uff1a\u68c0\u7d22\u6570\u636e\u7684 SQL \u67e5\u8be2\u3002 \u6253\u5f00\u6e38\u6807\uff1a OPEN cursor_name; \u767b\u5f55\u540e\u590d\u5236 \u83b7\u53d6\u6570\u636e\uff1a FETCH [NEXT | PRIOR | FIRST | LAST] FROM cursor_name INTO @variable1, @variable2, …; \u767b\u5f55\u540e\u590d\u5236 [NEXT | PRIOR | FIRST | LAST]\uff1a\u6307\u5b9a\u79fb\u52a8\u65b9\u5411\u3002 @variable1, @variable2, […]<\/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-5709","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5709","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=5709"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5709\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=5709"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=5709"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=5709"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}