{"id":1584,"date":"2022-11-18T23:29:49","date_gmt":"2022-11-18T15:29:49","guid":{"rendered":"https:\/\/qaqaq.top\/?p=1584"},"modified":"2022-12-19T20:20:57","modified_gmt":"2022-12-19T12:20:57","slug":"%e8%a7%a6%e5%8f%91%e5%99%a8%e8%af%be%e5%90%8e%e7%bb%83%e4%b9%a0","status":"publish","type":"post","link":"https:\/\/qaqaq.top\/?p=1584","title":{"rendered":"\u7b2c17\u7ae0\u89e6\u53d1\u5668\u8bfe\u540e\u7ec3\u4e60"},"content":{"rendered":"\n<pre class=\"wp-block-code\"><code># \u7b2c17\u7ae0_\u89e6\u53d1\u5668\u8bfe\u540e\u7ec3\u4e60\n\n# \u7ec3\u4e601\n\n#0. \u51c6\u5907\u5de5\u4f5c\n\nCREATE DATABASE test17_trigger;\n\nUSE test17_trigger;\n\nCREATE TABLE emps\nAS\n    SELECT employee_id,last_name,salary\n    FROM atguigudb.`employees`;\n\nSELECT * FROM emps;\n\n#1. \u590d\u5236\u4e00\u5f20emps\u8868\u7684\u7a7a\u8868emps_back\uff0c\u53ea\u6709\u8868\u7ed3\u6784\uff0c\u4e0d\u5305\u542b\u4efb\u4f55\u6570\u636e\n\nCREATE TABLE emps_back\nAS\n    SELECT * FROM emps\n    WHERE 1 = 2;\n\n#2. \u67e5\u8be2emps_back\u8868\u4e2d\u7684\u6570\u636e\nSELECT * FROM emps_back;\n\n#3. \u521b\u5efa\u89e6\u53d1\u5668emps_insert_trigger\uff0c\u6bcf\u5f53\u5411emps\u8868\u4e2d\u6dfb\u52a0\u4e00\u6761\u8bb0\u5f55\u65f6\uff0c\u540c\u6b65\u5c06\u8fd9\u6761\u8bb0\u5f55\u6dfb\u52a0\u5230emps_back\u8868\u4e2d\n\nDELIMITER \/\/\n\nCREATE TRIGGER emps_insert_trigger\n    AFTER INSERT ON emps\n    FOR EACH ROW\n    BEGIN\n        #\u5c06\u65b0\u6dfb\u52a0\u5230emps\u8868\u4e2d\u7684\u8bb0\u5f55\u6dfb\u52a0\u5230emp_bank\u8868\u4e2d\n        INSERT INTO emps_back(employee_id, last_name, salary)\n            VALUES(NEW.employee_id,NEW.last_name,NEW.salary);\n    END \/\/\n\nDELIMITER ;\n\n# SHOW TRIGGERS;\n\n#4. \u9a8c\u8bc1\u89e6\u53d1\u5668\u662f\u5426\u8d77\u4f5c\u7528\nSELECT * FROM emps;\n\nSELECT * FROM emps_back;\n\nINSERT INTO emps(employee_id, last_name, salary)\nVALUES(301,'Tom1',3600);\n\n# \u7ec3\u4e602\n\n#0. \u51c6\u5907\u5de5\u4f5c\uff1a\u4f7f\u7528\u7ec3\u4e601\u4e2d\u7684emps\u8868\n\n#1. \u590d\u5236\u4e00\u5f20emps\u8868\u7684\u7a7a\u8868emps_back1\uff0c\u53ea\u6709\u8868\u7ed3\u6784\uff0c\u4e0d\u5305\u542b\u4efb\u4f55\u6570\u636e\n\nCREATE TABLE emps_back1\nAS\n    SELECT *\n    FROM emps\n    WHERE 1 = 2;\n\n#2. \u67e5\u8be2emps_back1\u8868\u4e2d\u7684\u6570\u636e\n\nSELECT * FROM emps_back1;\n\n#3. \u521b\u5efa\u89e6\u53d1\u5668emps_del_trigger\uff0c\u6bcf\u5f53\u5411emps\u8868\u4e2d\u5220\u9664\u4e00\u6761\u8bb0\u5f55\u65f6\uff0c\u540c\u6b65\u5c06\u5220\u9664\u7684\u8fd9\u6761\u8bb0\u5f55\u6dfb\u52a0\u5230emps_back1\u8868\u4e2d\n\nDELIMITER \/\/\n\nCREATE TRIGGER emps_del_trigger\n    BEFORE DELETE ON emps\n    FOR EACH ROW\n    BEGIN\n        #\u5c06emp\u8868\u4e2d\u5220\u9664\u7684\u8bb0\u5f55\uff0c\u6dfb\u52a0\u5230emps_back1\u8868\u4e2d\n        INSERT INTO emps_back1(employee_id, last_name, salary)\n            VALUES(OLD.employee_id,OLD.last_name,OLD.salary);\n\n    END\/\/\n\nDELIMITER ;\n\n#4. \u9a8c\u8bc1\u89e6\u53d1\u5668\u662f\u5426\u8d77\u4f5c\u7528\n\nDELETE FROM emps\nWHERE employee_id = 101;\n\nDELETE FROM emps;\n\nSELECT * FROM emps;\n\nSELECT * FROM emps_back1;<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[47],"class_list":["post-1584","post","type-post","status-publish","format-standard","hentry","category-mysql-code","tag-mysql"],"_links":{"self":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1584"}],"collection":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1584"}],"version-history":[{"count":2,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1584\/revisions"}],"predecessor-version":[{"id":2674,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1584\/revisions\/2674"}],"wp:attachment":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1584"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1584"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1584"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}