{"id":2360,"date":"2025-03-04T20:27:08","date_gmt":"2025-03-04T12:27:08","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=2360"},"modified":"2025-03-04T20:27:08","modified_gmt":"2025-03-04T12:27:08","slug":"sqlite-%e8%a7%a6%e5%8f%91%e5%99%a8%ef%bc%88trigger%ef%bc%89","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/03\/04\/sqlite-%e8%a7%a6%e5%8f%91%e5%99%a8%ef%bc%88trigger%ef%bc%89\/","title":{"rendered":"SQLite\u00a0\u89e6\u53d1\u5668\uff08Trigger\uff09"},"content":{"rendered":"\n

\u5728 SQLite \u4e2d\uff0c\u89e6\u53d1\u5668\uff08Trigger\uff09<\/strong> \u662f\u4e00\u79cd\u6570\u636e\u5e93\u5bf9\u8c61\uff0c\u7528\u4e8e\u5728\u7279\u5b9a\u7684\u6570\u636e\u5e93\u64cd\u4f5c\uff08\u5982\u63d2\u5165\u3001\u66f4\u65b0\u6216\u5220\u9664\uff09\u53d1\u751f\u65f6\u81ea\u52a8\u6267\u884c\u9884\u5b9a\u4e49\u7684 SQL \u64cd\u4f5c\u3002\u89e6\u53d1\u5668\u53ef\u4ee5\u5e2e\u52a9\u81ea\u52a8\u5316\u6570\u636e\u7ba1\u7406\u8fc7\u7a0b\uff0c\u4f8b\u5982\u786e\u4fdd\u6570\u636e\u4e00\u81f4\u6027\u3001\u8bb0\u5f55\u65e5\u5fd7\u6216\u5b9e\u73b0\u590d\u6742\u7684\u6570\u636e\u9a8c\u8bc1\u3002<\/p>\n\n\n\n

1. \u89e6\u53d1\u5668\u7684\u57fa\u672c\u8bed\u6cd5<\/h3>\n\n\n\n

\u89e6\u53d1\u5668\u7684\u57fa\u672c\u8bed\u6cd5\u5982\u4e0b\uff1a<\/p>\n\n\n\n

CREATE TRIGGER trigger_name\ntrigger_time trigger_event\nON table_name\nFOR EACH ROW\nBEGIN\n  -- SQL \u64cd\u4f5c\nEND;<\/code><\/pre>\n\n\n\n
    \n
  • trigger_name<\/code>\uff1a\u89e6\u53d1\u5668\u7684\u540d\u79f0\u3002<\/li>\n\n\n\n
  • trigger_time<\/code>\uff1a\u89e6\u53d1\u5668\u89e6\u53d1\u7684\u65f6\u673a\uff0c\u53ef\u4ee5\u662f\uff1a<\/li>\n\n\n\n
  • BEFORE<\/code>\uff1a\u5728\u89e6\u53d1\u7684\u64cd\u4f5c\u4e4b\u524d\u6267\u884c\u3002<\/li>\n\n\n\n
  • AFTER<\/code>\uff1a\u5728\u89e6\u53d1\u7684\u64cd\u4f5c\u4e4b\u540e\u6267\u884c\u3002<\/li>\n\n\n\n
  • trigger_event<\/code>\uff1a\u89e6\u53d1\u5668\u54cd\u5e94\u7684\u4e8b\u4ef6\uff0c\u53ef\u4ee5\u662f\uff1a<\/li>\n\n\n\n
  • INSERT<\/code>\uff1a\u5728\u63d2\u5165\u64cd\u4f5c\u65f6\u89e6\u53d1\u3002<\/li>\n\n\n\n
  • UPDATE<\/code>\uff1a\u5728\u66f4\u65b0\u64cd\u4f5c\u65f6\u89e6\u53d1\u3002<\/li>\n\n\n\n
  • DELETE<\/code>\uff1a\u5728\u5220\u9664\u64cd\u4f5c\u65f6\u89e6\u53d1\u3002<\/li>\n\n\n\n
  • table_name<\/code>\uff1a\u89e6\u53d1\u5668\u5173\u8054\u7684\u8868\u3002<\/li>\n\n\n\n
  • FOR EACH ROW<\/code>\uff1a\u8868\u793a\u89e6\u53d1\u5668\u5bf9\u6bcf\u4e00\u884c\u6570\u636e\u7684\u64cd\u4f5c\u6267\u884c\u4e00\u6b21\u3002<\/li>\n\n\n\n
  • BEGIN ... END;<\/code>\uff1a\u5305\u542b\u6267\u884c\u7684 SQL \u8bed\u53e5\u3002<\/li>\n<\/ul>\n\n\n\n
    2. \u793a\u4f8b\uff1a\u63d2\u5165\u89e6\u53d1\u5668<\/h3>\n\n\n\n
    \u5047\u8bbe\u4f60\u6709\u4e00\u4e2a employees<\/code> \u8868\uff0c\u4f60\u5e0c\u671b\u5728\u63d2\u5165\u65b0\u5458\u5de5\u8bb0\u5f55\u65f6\uff0c\u81ea\u52a8\u8bb0\u5f55\u5f53\u524d\u65f6\u95f4\u4e3a\u8be5\u5458\u5de5\u7684\u5165\u804c\u65f6\u95f4\u3002<\/p>\n\n\n\n
    \u521b\u5efa employees<\/code> \u8868\u7684\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n
    CREATE TABLE employees (\n    id INTEGER PRIMARY KEY,\n    first_name TEXT,\n    last_name TEXT,\n    hire_date TEXT\n);<\/code><\/pre>\n\n\n\n
    \u521b\u5efa\u89e6\u53d1\u5668\uff1a<\/strong><\/p>\n\n\n\n
    CREATE TRIGGER set_hire_date\nAFTER INSERT\nON employees\nFOR EACH ROW\nBEGIN\n  UPDATE employees\n  SET hire_date = CURRENT_TIMESTAMP\n  WHERE id = NEW.id;\nEND;<\/code><\/pre>\n\n\n\n
    \u8fd9\u4e2a\u89e6\u53d1\u5668\u4f1a\u5728\u6bcf\u6b21\u5411 employees<\/code> \u8868\u63d2\u5165\u4e00\u884c\u6570\u636e\u540e\uff0c\u81ea\u52a8\u8bbe\u7f6e\u8be5\u5458\u5de5\u7684 hire_date<\/code> \u4e3a\u5f53\u524d\u65f6\u95f4\u3002<\/p>\n\n\n\n
    3. \u793a\u4f8b\uff1a\u5220\u9664\u89e6\u53d1\u5668<\/h3>\n\n\n\n
    \u5047\u8bbe\u4f60\u6709\u4e00\u4e2a logs<\/code> \u8868\uff0c\u8bb0\u5f55\u6240\u6709\u64cd\u4f5c\u65e5\u5fd7\uff0c\u5f53\u5458\u5de5\u88ab\u5220\u9664\u65f6\uff0c\u4f60\u5e0c\u671b\u8bb0\u5f55\u4e00\u6761\u5220\u9664\u65e5\u5fd7\u3002<\/p>\n\n\n\n
    \u521b\u5efa logs<\/code> \u8868\uff1a<\/strong><\/p>\n\n\n\n
    CREATE TABLE logs (\n    log_id INTEGER PRIMARY KEY,\n    action TEXT,\n    employee_id INTEGER,\n    timestamp TEXT\n);<\/code><\/pre>\n\n\n\n
    \u521b\u5efa\u89e6\u53d1\u5668\uff1a<\/strong><\/p>\n\n\n\n
    CREATE TRIGGER log_employee_deletion\nAFTER DELETE\nON employees\nFOR EACH ROW\nBEGIN\n  INSERT INTO logs (action, employee_id, timestamp)\n  VALUES ('Deleted employee', OLD.id, CURRENT_TIMESTAMP);\nEND;<\/code><\/pre>\n\n\n\n
    \u8fd9\u4e2a\u89e6\u53d1\u5668\u4f1a\u5728\u6bcf\u6b21\u5220\u9664 employees<\/code> \u8868\u4e2d\u7684\u8bb0\u5f55\u65f6\uff0c\u5411 logs<\/code> \u8868\u63d2\u5165\u4e00\u6761\u5220\u9664\u8bb0\u5f55\u3002<\/p>\n\n\n\n
    4. \u793a\u4f8b\uff1a\u66f4\u65b0\u89e6\u53d1\u5668<\/h3>\n\n\n\n
    \u5047\u8bbe\u4f60\u6709\u4e00\u4e2a employees<\/code> \u8868\u548c\u4e00\u4e2a salary_changes<\/code> \u8868\uff0c\u5f53\u5458\u5de5\u7684\u85aa\u6c34\u53d1\u751f\u53d8\u52a8\u65f6\uff0c\u4f60\u5e0c\u671b\u8bb0\u5f55\u4e00\u6761\u85aa\u8d44\u53d8\u52a8\u8bb0\u5f55\u3002<\/p>\n\n\n\n
    \u521b\u5efa salary_changes<\/code> \u8868\uff1a<\/strong><\/p>\n\n\n\n
    CREATE TABLE salary_changes (\n    change_id INTEGER PRIMARY KEY,\n    employee_id INTEGER,\n    old_salary REAL,\n    new_salary REAL,\n    change_date TEXT\n);<\/code><\/pre>\n\n\n\n
    \u521b\u5efa\u89e6\u53d1\u5668\uff1a<\/strong><\/p>\n\n\n\n
    CREATE TRIGGER log_salary_update\nAFTER UPDATE OF salary\nON employees\nFOR EACH ROW\nBEGIN\n  INSERT INTO salary_changes (employee_id, old_salary, new_salary, change_date)\n  VALUES (OLD.id, OLD.salary, NEW.salary, CURRENT_TIMESTAMP);\nEND;<\/code><\/pre>\n\n\n\n
    \u8fd9\u4e2a\u89e6\u53d1\u5668\u4f1a\u5728 employees<\/code> \u8868\u7684 salary<\/code> \u5217\u88ab\u66f4\u65b0\u65f6\uff0c\u5411 salary_changes<\/code> \u8868\u63d2\u5165\u4e00\u6761\u8bb0\u5f55\uff0c\u8bb0\u5f55\u5458\u5de5\u7684\u85aa\u8d44\u53d8\u52a8\u3002<\/p>\n\n\n\n
    5. \u5220\u9664\u89e6\u53d1\u5668<\/h3>\n\n\n\n
    \u5982\u679c\u4e0d\u518d\u9700\u8981\u67d0\u4e2a\u89e6\u53d1\u5668\uff0c\u53ef\u4ee5\u901a\u8fc7 DROP TRIGGER<\/code> \u8bed\u53e5\u5220\u9664\u5b83\uff1a<\/p>\n\n\n\n
    DROP TRIGGER IF EXISTS trigger_name;<\/code><\/pre>\n\n\n\n
    6. \u6ce8\u610f\u4e8b\u9879<\/h3>\n\n\n\n
      \n
    • \u89e6\u53d1\u5668\u53ea\u80fd\u5728\u8868\u7ea7\u522b\u521b\u5efa\uff0c\u4e0d\u80fd\u5728\u89c6\u56fe\u4e0a\u521b\u5efa\u3002<\/li>\n\n\n\n
    • SQLite \u89e6\u53d1\u5668\u7684\u6267\u884c\u987a\u5e8f\u662f\uff1aBEFORE<\/code> \u89e6\u53d1\u5668\u5148\u6267\u884c\uff0cAFTER<\/code> \u89e6\u53d1\u5668\u540e\u6267\u884c\u3002<\/li>\n\n\n\n
    • \u89e6\u53d1\u5668\u53ef\u4ee5\u4f7f\u7528 NEW<\/code> \u548c OLD<\/code> \u5173\u952e\u5b57\u6765\u8bbf\u95ee\u65b0\u503c\u548c\u65e7\u503c\uff1a<\/li>\n\n\n\n
    • NEW.column_name<\/code>\uff1a\u8bbf\u95ee\u63d2\u5165\u6216\u66f4\u65b0\u64cd\u4f5c\u4e2d\u7684\u65b0\u503c\u3002<\/li>\n\n\n\n
    • OLD.column_name<\/code>\uff1a\u8bbf\u95ee\u66f4\u65b0\u6216\u5220\u9664\u64cd\u4f5c\u4e2d\u7684\u65e7\u503c\u3002<\/li>\n<\/ul>\n\n\n\n
      \u901a\u8fc7\u89e6\u53d1\u5668\uff0c\u4f60\u53ef\u4ee5\u81ea\u52a8\u5316\u6570\u636e\u5e93\u64cd\u4f5c\uff0c\u589e\u5f3a\u6570\u636e\u7684\u5b8c\u6574\u6027\u548c\u4e00\u81f4\u6027\u3002\u66f4\u591a\u8be6\u7ec6\u5185\u5bb9\u8bf7\u5173\u6ce8\u5176\u4ed6\u76f8\u5173\u6587\u7ae0\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
      \u5728 SQLite \u4e2d\uff0c\u89e6\u53d1\u5668\uff08Trigger\uff09 \u662f\u4e00\u79cd\u6570\u636e\u5e93\u5bf9\u8c61\uff0c\u7528\u4e8e\u5728\u7279\u5b9a\u7684\u6570\u636e\u5e93\u64cd\u4f5c\uff08\u5982\u63d2\u5165\u3001\u66f4\u65b0\u6216\u5220\u9664\uff09 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[76],"tags":[],"class_list":["post-2360","post","type-post","status-publish","format-standard","hentry","category-sqlite"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2360","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/comments?post=2360"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2360\/revisions"}],"predecessor-version":[{"id":2361,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2360\/revisions\/2361"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=2360"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=2360"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=2360"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}