{"id":1018,"date":"2017-10-30T16:22:22","date_gmt":"2017-10-30T08:22:22","guid":{"rendered":"http:\/\/www.5x44.cn\/?p=1018"},"modified":"2017-11-01T15:41:04","modified_gmt":"2017-11-01T07:41:04","slug":"mysql5-7-%e8%a7%a6%e5%8f%91%e5%99%a8%e8%af%ad%e6%b3%95%e5%92%8c%e4%be%8b%e5%ad%90","status":"publish","type":"post","link":"https:\/\/www.5x44.cn\/?p=1018","title":{"rendered":"MYSQL5.7 \u89e6\u53d1\u5668\u8bed\u6cd5\u548c\u4f8b\u5b50"},"content":{"rendered":"<p>\u521b\u5efa\u548c\u5220\u9664\u89e6\u53d1\u5668\u4f7f\u7528CREATE TRIGGER\u6216DROP TRIGER\u8bed\u53e5\uff1a<\/p>\n<pre class=\"programlisting line-numbers language-sql\"><code class=\" language-sql\"><span class=\"token keyword\">CREATE<\/span>\r\n    <span class=\"token punctuation\">[<\/span><span class=\"token keyword\">DEFINER<\/span> <span class=\"token operator\">=<\/span> { <span class=\"token keyword\"><em class=\"replaceable\">user<\/em><\/span> <span class=\"token operator\">|<\/span> <span class=\"token keyword\">CURRENT_USER<\/span> }<span class=\"token punctuation\">]<\/span>\r\n    <span class=\"token keyword\">TRIGGER<\/span> <em class=\"replaceable\">trigger_name<\/em>\r\n    <em class=\"replaceable\">trigger_time<\/em> <em class=\"replaceable\">trigger_event<\/em>\r\n    <span class=\"token keyword\">ON<\/span> <em class=\"replaceable\">tbl_name<\/em> <span class=\"token keyword\">FOR<\/span> <span class=\"token keyword\">EACH<\/span> <span class=\"token keyword\">ROW<\/span>\r\n    <span class=\"token punctuation\">[<\/span><em class=\"replaceable\">trigger_order<\/em><span class=\"token punctuation\">]<\/span>\r\n    <em class=\"replaceable\">trigger_body<\/em>\r\n\r\n<em class=\"replaceable\">trigger_time<\/em>: { <span class=\"token keyword\">BEFORE<\/span> <span class=\"token operator\">|<\/span> <span class=\"token keyword\">AFTER<\/span> }\r\n\r\n<em class=\"replaceable\">trigger_event<\/em>: { <span class=\"token keyword\">INSERT<\/span> <span class=\"token operator\">|<\/span> <span class=\"token keyword\">UPDATE<\/span> <span class=\"token operator\">|<\/span> <span class=\"token keyword\">DELETE<\/span> }\r\n\r\n<em class=\"replaceable\">trigger_order<\/em>: { <span class=\"token keyword\">FOLLOWS<\/span> <span class=\"token operator\">|<\/span> <span class=\"token keyword\">PRECEDES<\/span> } <em class=\"replaceable\">other_trigger_name<\/em><\/code><\/pre>\n<p>\u8fd9\u6709\u4e00\u4e2a\u7531insert\u64cd\u4f5c\u6fc0\u6d3b\u89e6\u53d1\u5668\u7684\u7b80\u5355\u4f8b\u5b50\uff0c\u8fd9\u4e2a\u4f8b\u5b50\u662f\u4e00\u4e2a\u7d2f\u52a0\u5668\uff0c\u6c47\u603b\u63d2\u5165\u7684\u884c\u6570\u3002<\/p>\n<pre class=\"programlisting line-numbers language-sql\"><code class=\" language-sql\"><span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">CREATE<\/span> <span class=\"token keyword\">TABLE<\/span> <span class=\"token keyword\">account<\/span> <span class=\"token punctuation\">(<\/span>acct_num <span class=\"token datatype\">INT<\/span><span class=\"token punctuation\">,<\/span> amount <span class=\"token datatype\">DECIMAL<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">10<\/span><span class=\"token punctuation\">,<\/span><span class=\"token number\">2<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token output\">Query OK, 0 rows affected (0.03 sec)<\/span>\r\n\r\n<span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">CREATE<\/span> <span class=\"token keyword\">TRIGGER<\/span> ins_sum <span class=\"token keyword\">BEFORE<\/span> <span class=\"token keyword\">INSERT<\/span> <span class=\"token keyword\">ON<\/span> <span class=\"token keyword\">account<\/span>\r\n       <span class=\"token keyword\">FOR<\/span> <span class=\"token keyword\">EACH<\/span> <span class=\"token keyword\">ROW<\/span> <span class=\"token keyword\">SET<\/span> <span class=\"token variable\">@sum<\/span> <span class=\"token operator\">=<\/span> <span class=\"token variable\">@sum<\/span> <span class=\"token operator\">+<\/span> <span class=\"token keyword\">NEW<\/span><span class=\"token punctuation\">.<\/span>amount<span class=\"token punctuation\">;<\/span>\r\n<span class=\"token output\">Query OK, 0 rows affected (0.01 sec)<\/span><\/code><\/pre>\n<p>CREATE TRIGGER\u8bed\u53e5\u521b\u5efa\u4e00\u4e2a\u540d\u4e3ains_sum\u7684\u89e6\u53d1\u5668\uff0c\u4f5c\u7528\u4e8eaccount\u8868\u4e0a\u3002\u5b83\u5305\u542b\u7684\u5b50\u53e5\u6709\uff1a\u52a8\u4f5c\u65f6\u95f4\uff0c\u89e6\u53d1\u4e8b\u4ef6\u548c\u89e6\u53d1\u540e\u7684\u76f8\u5e94\u52a8\u4f5c\uff1a<\/p>\n<ul>\n<li>\u5173\u952e\u5b57BEFORE\u6307\u793a\u4e86\u89e6\u53d1\u5668\u7684\u65f6\u95f4\u3002\u672c\u4f8b\u4e2d\u89e6\u53d1\u52a8\u4f5c\u53d1\u751f\u5728\u63d2\u5165\u8868\u4e4b\u524d\u3002\u76f8\u5e94\u7684\u5173\u952e\u5b57\u662fAFTER\u3002<\/li>\n<li>\u5173\u952e\u5b57INSERT\u6307\u793a\u89e6\u53d1\u4e8b\u4ef6\uff1bINSERT\u8fd9\u79cd\u64cd\u4f5c\u53ef\u4ee5\u6fc0\u6d3b\u89e6\u53d1\u5668\u3002\u4f60\u540c\u6837\u80fd\u5efa\u7acbDELETE\u548cUPDATE\u64cd\u4f5c\u7684\u89e6\u53d1\u5668\u3002<\/li>\n<li>FOR EACH ROW\u8bed\u53e5\u5b9a\u4e49\u4e86\u89e6\u53d1\u4f53\uff1b\u89e6\u53d1\u4f53\u5728\u6bcf\u6b21\u89e6\u53d1\u5668\u88ab\u6fc0\u6d3b\u65f6\u505a\u7528\u4e8e\u5bf9\u5e94\u7684\u8bb0\u5f55\u3002\u5728\u672c\u4f8b\u4e2d\uff0c\u89e6\u53d1\u4f53\u53ea\u662f\u628aamount\u7684\u6570\u503c\u7d2f\u52a0\u5230\u4e00\u8d77\uff0c\u7136\u540e\u653e\u5230\u7528\u6237\u53d8\u91cfsum\u4e2d\u3002NEW.amount\u7684\u610f\u601d\u662f\u201c\u521a\u63d2\u5165\u5230\u8868\u7684\u65b0\u8bb0\u5f55\u7684amount\u5217\u201d\u3002<\/li>\n<\/ul>\n<p>\u4f7f\u7528\u89e6\u53d1\u5668\uff0c\u8bbe\u7f6e\u7d2f\u52a0\u5668\u53d8\u91cf\u7684\u503c\u4e3a0\uff0c\u6267\u884cINSERT\u64cd\u4f5c\uff0c\u7136\u540e\u770b\u7528\u6237\u53d8\u91cf\u7684\u53d8\u5316\uff1a<\/p>\n<pre class=\"programlisting line-numbers language-sql\"><code class=\" language-sql\"><span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">SET<\/span> <span class=\"token variable\">@sum<\/span> <span class=\"token operator\">=<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">INSERT<\/span> <span class=\"token keyword\">INTO<\/span> <span class=\"token keyword\">account<\/span> <span class=\"token keyword\">VALUES<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">137<\/span><span class=\"token punctuation\">,<\/span><span class=\"token number\">14.98<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">141<\/span><span class=\"token punctuation\">,<\/span><span class=\"token number\">1937.50<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span><span class=\"token punctuation\">(<\/span><span class=\"token number\">97<\/span><span class=\"token punctuation\">,<\/span><span class=\"token operator\">-<\/span><span class=\"token number\">100.00<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">SELECT<\/span> <span class=\"token variable\">@sum<\/span> <span class=\"token keyword\">AS<\/span> <span class=\"token string\">'Total amount inserted'<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span> Total amount inserted <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>               1852.48 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span><\/code><\/pre>\n<p>\u5728\u672c\u4f8b\u4e2d@sum\u7684\u503c\u5728INSERT\u4e4b\u540e\u4f1a\u6267\u884c14.98+1937.50-100\u3002<\/p>\n<p>\u5220\u9664\u89e6\u53d1\u5668\u4f7f\u7528\uff1aDROP TRIGGER\u8bed\u53e5\u3002\u5fc5\u987b\u6307\u5b9a\u6570\u636e\u5e93\u540d\uff0c\u9664\u975e\u5df2\u7ecf\u6709\u4e86\u9ed8\u8ba4\u6570\u636e\u5e93\u3002<\/p>\n<p>\u5982\u679c\u4f60\u5220\u9664\u4e86\u8868\uff0c\u90a3\u4e48\u548c\u8868\u76f8\u5173\u7684\u89e6\u53d1\u5668\u4e5f\u4f1a\u88ab\u5220\u9664\u3002<\/p>\n<p>\u89e6\u53d1\u5668\u540d\u5b58\u5728\u4e8e\u6570\u636e\u5e93\u6a21\u578b\u7684\u540d\u5b57\u7a7a\u95f4\u4e2d\uff0c\u8fd9\u610f\u5473\u7740\u5728\u540c\u4e00\u4e2a\u6570\u636e\u5e93\u4e0b\u7684\u6240\u6709\u89e6\u53d1\u5668\u5fc5\u987b\u6709\u4e0d\u540c\u7684\u540d\u5b57\u3002<\/p>\n<p>MYSQL 5.7.2\u4e2d\uff0c\u53ef\u4ee5\u4e3a\u4e00\u4e2a\u8868\u5b9a\u4e49\u591a\u4e2a\u76f8\u540c\u4e8b\u4ef6\u548c\u89e6\u53d1\u65f6\u95f4\u7684\u89e6\u53d1\u5668\u3002\u4f8b\u5982\uff0c\u4f60\u53ef\u4ee5\u6709\u4e24\u4e2aBEFORE UPDATE\u89e6\u53d1\u5668\u653e\u5728\u540c\u4e00\u4e2a\u8868\u4e0a\u3002<strong>\u9ed8\u8ba4\u60c5\u51b5\u4e0b\uff0c\u5177\u6709\u76f8\u540c\u89e6\u53d1\u4e8b\u4ef6\u548c\u65f6\u95f4\u7684\u89e6\u53d1\u5668\u4f1a\u6309\u521b\u5efa\u7684\u5148\u540e\u987a\u5e8f\u88ab\u6fc0\u6d3b\u4f7f\u7528<\/strong>\u3002\u5982\u679c\u8981\u6539\u53d8\u89e6\u53d1\u5668\u987a\u5e8f\uff0c\u8981\u4e3aFOR EACH ROW\u547d\u4ee4\u6307\u5b9aFOLLOWS\u6216PRECEDES\uff0c\u8fd9\u6837\u76f8\u540c\u89e6\u53d1\u4e8b\u4ef6\u548c\u65f6\u95f4\u7684\u89e6\u53d1\u5668\u5c31\u53ef\u4ee5\u6309\u6307\u5b9a\u7684\u987a\u5e8f\u6267\u884c\u3002FOLLOWS\uff1a\u65b0\u5efa\u7684\u89e6\u53d1\u5668\u540e\u6267\u884c\uff1bPRECEDES\uff1a\u65b0\u5efa\u7684\u89e6\u53d1\u5668\u5148\u6267\u884c\u3002<\/p>\n<p>\u4f8b\u5982\uff1a\u4e0b\u9762\u4e3aaccount\u8868\u5efa\u7acb\u53e6\u4e00\u4e2aBEFORE INSERT\u89e6\u53d1\u5668<\/p>\n<pre class=\"programlisting line-numbers language-sql\"><code class=\" language-sql\"><span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">CREATE<\/span> <span class=\"token keyword\">TRIGGER<\/span> ins_transaction <span class=\"token keyword\">BEFORE<\/span> <span class=\"token keyword\">INSERT<\/span> <span class=\"token keyword\">ON<\/span> <span class=\"token keyword\">account<\/span>\r\n       <span class=\"token keyword\">FOR<\/span> <span class=\"token keyword\">EACH<\/span> <span class=\"token keyword\">ROW<\/span> <span class=\"token keyword\">PRECEDES<\/span> ins_sum\r\n       <span class=\"token keyword\">SET<\/span>\r\n       <span class=\"token variable\">@deposits<\/span> <span class=\"token operator\">=<\/span> <span class=\"token variable\">@deposits<\/span> <span class=\"token operator\">+<\/span> <span class=\"token function\">IF<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">NEW<\/span><span class=\"token punctuation\">.<\/span>amount<span class=\"token operator\">&gt;<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">,<\/span><span class=\"token keyword\">NEW<\/span><span class=\"token punctuation\">.<\/span>amount<span class=\"token punctuation\">,<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span>\r\n       <span class=\"token variable\">@withdrawals<\/span> <span class=\"token operator\">=<\/span> <span class=\"token variable\">@withdrawals<\/span> <span class=\"token operator\">+<\/span> <span class=\"token function\">IF<\/span><span class=\"token punctuation\">(<\/span><span class=\"token keyword\">NEW<\/span><span class=\"token punctuation\">.<\/span>amount<span class=\"token operator\">&lt;<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">,<\/span><span class=\"token operator\">-<\/span><span class=\"token keyword\">NEW<\/span><span class=\"token punctuation\">.<\/span>amount<span class=\"token punctuation\">,<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token output\">Query OK, 0 rows affected (0.01 sec)<\/span><\/code><\/pre>\n<p>\u8fd9\u4e2a\u89e6\u53d1\u5668\uff0cins_transaction\uff0c\u7c7b\u4f3c\u4e8eins_sum\uff0c\u4f46\u662f\u7d2f\u52a0\u5668@deposits\u548c@withdrawals\u662f\u5206\u5f00\u7684\u3002\u5b83\u4f7f\u7528\u4e86PRECEDES\u5b50\u53e5\uff0c\u5bfc\u81f4\u5b83\u5728ins_sum\u4e4b\u524d\u6267\u884c\uff1b\u5982\u679c\u6ca1\u6709\u8fd9\u4e2a\u5b50\u53e5\uff0c\u5c31\u4f1a\u5728ins_sum\u4e4b\u540e\u6267\u884c\uff0c\u56e0\u4e3a\u5b83\u5728ins_sum\u4e4b\u540e\u521b\u5efa\u7684\u3002<\/p>\n<p>\u5728MYSQL5.7.2\u4e4b\u524d\uff0c\u4e0d\u80fd\u4e3a\u4e00\u4e2a\u8868\u5efa\u7acb\u540c\u6837\u89e6\u53d1\u4e8b\u4ef6\u548c\u65f6\u95f4\u548c\u591a\u4e2a\u89e6\u53d1\u5668\u3002\u4f8b\u5982\uff0c\u4f60\u4e0d\u80fd\u4e3a\u540c\u4e00\u4e2a\u8868\u5efa\u7acb\u4e24\u4e2aBEFORE UPDATE\u3002\u4e3a\u4e86\u7ed5\u5f00\u8fd9\u4e2a\u95ee\u9898\uff0c\u4f60\u53ef\u4ee5\u5b9a\u4e49\u4e00\u4e2a\u89e6\u53d1\u5668\uff0c\u5728FOR EACH ROW\u4e2d\u4f7f\u7528BEGIN &#8230; END\u6267\u884c\u591a\u4e2a\u8bed\u53e5\u5757\u6765\u5b9e\u73b0\u3002<\/p>\n<p>\u5728\u89e6\u53d1\u4f53\u4e2d\uff0c<span style=\"color: #ff0000;\">OLD<\/span>\u548c<span style=\"color: #ff0000;\">NEW<\/span>\u5173\u952e\u5b57\u5141\u8bb8\u4f60\u8bbf\u95ee\u88ab\u89e6\u53d1\u5668\u4f5c\u7528\u7684\u90a3\u4e00\u884c\u8bb0\u5f55\u3002OLD\u548cNEW\u662fMYSQL\u5bf9\u89e6\u53d1\u5668\u7684\u6269\u5c55\u3002\u5b83\u4eec\u662f\u5927\u5c0f\u5199\u4e0d\u654f\u611f\u7684\u3002<\/p>\n<p>\u5728<span style=\"color: #0000ff;\">INSERT TRIGGER<\/span>\u4e2d\u53ea\u6709NEW.col_name\u80fd\u88ab\u4f7f\u7528\uff1b\u6ca1\u6709OLD\u8bb0\u5f55\u3002\u5728<span style=\"color: #0000ff;\">DELETE TRIGGER<\/span>\u4e2d\uff0c\u53ea\u6709OLD.col_name\u80fd\u88ab\u4f7f\u7528\uff1b\u6ca1\u6709NEW\u8bb0\u5f55\u3002\u5728<span style=\"color: #0000ff;\">UPDATE TRIGGER<\/span>\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528OLD.col_name\u6307\u5411\u8bb0\u5f55\u88ab\u4fee\u6539\u4e4b\u524d\u7684\u884c\uff0c\u800cNEW.col_name\u6307\u5411\u8bb0\u5f55\u88ab\u4fee\u6539\u4e4b\u540e\u7684\u884c\u3002<\/p>\n<p>\u88ab\u547d\u540d\u4e3aOLD\u7684\u8bb0\u5f55\u662f\u53ea\u8bfb\u7684\u3002\u5982\u679c\u6709SELECT\u6743\u9650\u5c31\u53ef\u4ee5\u8bfb\u5b83\u4eec\uff0c\u4f46\u4e0d\u80fd\u4fee\u6539\u3002\u53ea\u8981\u6709SELECT\u6743\u9650\u5c31\u53ef\u4ee5\u6307\u5411NEW\u7684\u8bb0\u5f55\u3002\u5728BEFORE \u89e6\u53d1\u5668\u4e2d\uff0c\u53ea\u8981\u6709UPDATE\u6743\u9650\u5c31\u53ef\u4ee5\u6539\u53d8NEW\u7684\u503c\uff0c<code>SET NEW.COL_NAME =VALUE<\/code>\u3002\u8fd9\u610f\u5473\u7740\u4f60\u80fd\u4f7f\u7528\u89e6\u53d1\u5668\u4fee\u6539\u63d2\u5165\u6216\u66f4\u65b0\u5230\u8868\u4e2d\u7684\u65b0\u8bb0\u5f55\u3002\uff08SET\u4e0d\u80fd\u7528\u4e8eAFTER\u89e6\u53d1\u5668\u4e0a\uff0c\u56e0\u4e3a\u6539\u53d8\u5df2\u7ecf\u53d1\u751f\u4e86\u3002\uff09<\/p>\n<p><strong>\u5728BEFORE\u89e6\u53d1\u5668\u4e2d\uff0c\u7528\u4e8eAUTO_INCREAMENT\u5c5e\u6027\u5217\u7684NEW\u662f0\uff0c\u4e0d\u4f1a\u83b7\u5f97\u81ea\u52a8\u589e\u957f\u4ea7\u751f\u7684\u65b0\u503c\u3002<\/strong><\/p>\n<p>\u901a\u8fc7\u4f7f\u7528BEGIN &#8230; END\u7ed3\u6784\uff0c\u53ef\u4ee5\u5b9a\u4e49\u4e00\u4e2a\u6267\u884c\u591a\u884c\u8bed\u53e5\u7684\u89e6\u53d1\u5668\u3002\u5728BEGIN\u5757\u4e2d\uff0c\u4f60\u80fd\u50cf\u4f7f\u7528\u5728\u5176\u5b83\u4f8b\u7a0b\uff08routine\uff09\u4e00\u6837\u4f7f\u7528\u6761\u4ef6\u548c\u5faa\u73af\u3002\u4f46\u662f\uff0c\u5c31\u5982\u5b58\u50a8\u7684\u4f8b\u7a0b\u4e00\u6837\uff0c\u5982\u679c\u4f60\u4f7f\u7528mysql\u5ba2\u6237\u7aef\u5b9a\u4e49\u51fa\u53d1\u5668\uff0c\u53bb\u6267\u884c\u591a\u6761\u8bed\u53e5\uff0c\u9700\u8981\u91cd\u65b0\u5b9a\u4e49\u6362\u884c\u7b26\uff08delimiter\u547d\u4ee4\uff09\u3002\u4e0b\u9762\u7684\u4f8b\u5b50\u8bf4\u660e\u4e86\u8fd9\u4e00\u70b9\u3002\u5b83\u5b9a\u4e49\u4e86\u4e00\u4e2aUPDATE\u89e6\u53d1\u5668\uff0c\u8be5\u89e6\u53d1\u5668\u68c0\u67e5\u7528\u4e8e\u66f4\u65b0\u7684\u65b0\u503c\uff0c\u5e76\u4fee\u6539\u8be5\u503c\u7684\u8303\u56f4\u52300~100\u4e4b\u95f4\u3002\u8fd9\u5fc5\u987b\u662fBEFORE\u89e6\u53d1\u5668\uff0c\u56e0\u4e3a\u8fd9\u4e2a\u503c\u5fc5\u987b\u5728\u66f4\u65b0\u524d\u8fdb\u884c\u68c0\u67e5\uff1a<\/p>\n<pre class=\"programlisting line-numbers language-sql\"><code class=\" language-sql\"><span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">delimiter<\/span> <span class=\"token comment\" spellcheck=\"true\">\/\/<\/span>\r\n<span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">CREATE<\/span> <span class=\"token keyword\">TRIGGER<\/span> upd_check <span class=\"token keyword\">BEFORE<\/span> <span class=\"token keyword\">UPDATE<\/span> <span class=\"token keyword\">ON<\/span> <span class=\"token keyword\">account<\/span>\r\n       <span class=\"token keyword\">FOR<\/span> <span class=\"token keyword\">EACH<\/span> <span class=\"token keyword\">ROW<\/span>\r\n       <span class=\"token keyword\">BEGIN<\/span>\r\n           <span class=\"token keyword\">IF<\/span> <span class=\"token keyword\">NEW<\/span><span class=\"token punctuation\">.<\/span>amount <span class=\"token operator\">&lt;<\/span> <span class=\"token number\">0<\/span> <span class=\"token keyword\">THEN<\/span>\r\n               <span class=\"token keyword\">SET<\/span> <span class=\"token keyword\">NEW<\/span><span class=\"token punctuation\">.<\/span>amount <span class=\"token operator\">=<\/span> <span class=\"token number\">0<\/span><span class=\"token punctuation\">;<\/span>\r\n           <span class=\"token keyword\">ELSEIF<\/span> <span class=\"token keyword\">NEW<\/span><span class=\"token punctuation\">.<\/span>amount <span class=\"token operator\">&gt;<\/span> <span class=\"token number\">100<\/span> <span class=\"token keyword\">THEN<\/span>\r\n               <span class=\"token keyword\">SET<\/span> <span class=\"token keyword\">NEW<\/span><span class=\"token punctuation\">.<\/span>amount <span class=\"token operator\">=<\/span> <span class=\"token number\">100<\/span><span class=\"token punctuation\">;<\/span>\r\n           <span class=\"token keyword\">END<\/span> <span class=\"token keyword\">IF<\/span><span class=\"token punctuation\">;<\/span>\r\n       <span class=\"token keyword\">END<\/span><span class=\"token punctuation\">;<\/span><span class=\"token comment\" spellcheck=\"true\">\/\/<\/span>\r\n<span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">delimiter<\/span> <span class=\"token punctuation\">;<\/span><\/code><\/pre>\n<p>\u4e5f\u53ef\u4ee5\u901a\u8fc7\u5b9a\u4e49\u4e00\u4e2a\u5b58\u50a8\u8fc7\u7a0b\uff0c\u7136\u540e\u5728\u89e6\u53d1\u5668\u4e2d\u7528CALL\u8c03\u7528\u8be5\u5b58\u50a8\u8fc7\u7a0b\u7684\u65b9\u6cd5\u3002\u5982\u679c\u60f3\u670d\u7528\u8be5\u6bb5\u4ee3\u7801\uff0c\u8fd9\u79cd\u65b9\u6cd5\u66f4\u597d\u3002<\/p>\n<p>\u5728\u89e6\u53d1\u5668\u6267\u884c\u65f6\u6709\u4e00\u4e9b\u9650\u5236\uff1a<\/p>\n<ul>\n<li>\u89e6\u53d1\u5668\u4e0d\u80fd\u4f7f\u7528CALL\u8bed\u53e5\u8c03\u7528\u5b58\u50a8\u8fc7\u7a0b\u7684\u8fd4\u56de\u503c\u5230\u5ba2\u6237\u7aef\u6216\u52a8\u6001SQL\u4e2d\uff08dynamic SQL\uff09\uff0c\u4f46\u89e6\u53d1\u5668\u5141\u8bb8\u5b58\u50a8\u8fc7\u7a0b\u6709\u8fd4\u56de\u503c\uff0cOUT\u6216INOUT\u7c7b\u578b\u7684\u53c2\u6570\u3002<\/li>\n<li>\u89e6\u53d1\u5668\u4e0d\u80fd\u663e\u793a\u6216\u9690\u793a\u7684\u5f00\u542f\u6216\u7ed3\u675f\u4e00\u4e2a\u4e8b\u52a1\uff0c\u5982\uff1aSTART TRANSACTION, COMMIT\u6216ROLLBACK\u3002\uff08\u4f46ROLLBACK TO SAVEPOINT\u662f\u53ef\u4ee5\u4f7f\u7528\u7684\uff0c\u56e0\u4e3a\u5b83\u5e76\u6ca1\u6709\u7ed3\u675f\u4e00\u4e2a\u4e8b\u52a1\uff09See also <a class=\"xref\" title=\"C.1\u00a0Restrictions on Stored Programs\" href=\"https:\/\/dev.mysql.com\/doc\/refman\/5.7\/en\/stored-program-restrictions.html\">Section\u00a0C.1, \u201cRestrictions on Stored Programs\u201d<\/a>.<\/li>\n<\/ul>\n<p>MYSQL\u7684\u89e6\u53d1\u5668\u6267\u884c\u671f\u95f4\u5904\u7406\u9519\u8bef\u7684\u6d41\u7a0b\u5982\u4e0b\uff1a<\/p>\n<ul>\n<li>\u5982\u679cBEFORE\u89e6\u53d1\u5668\u5931\u8d25\uff0c\u64cd\u4f5c\u7684\u76f8\u5e94\u8bb0\u5f55\u4e0d\u4f1a\u88ab\u6267\u884c\u3002<\/li>\n<li>\u4e00\u4e2aBEFORE\u89e6\u53d1\u5668\u7531attempt\u6fc0\u6d3b\u63d2\u5165\u6216\u4fee\u6539\u884c\uff0c\u65e0\u8bba\u6210\u529f\u4e8e\u5426\u90fd\u4f1a\u88ab\u5ffd\u7565\u3002<\/li>\n<li>AFTER\u89e6\u53d1\u5668\u53ea\u6709\u5f53BEFORE\u89e6\u53d1\u5668\u6267\u884c\u6210\u529f\u540e\u624d\u4f1a\u6267\u884c\u3002<\/li>\n<li>An error during either a <code class=\"literal\">BEFORE<\/code> or <code class=\"literal\">AFTER<\/code> trigger results in failure of the entire statement that caused trigger invocation.<\/li>\n<li>\u5bf9\u4e8e\u4e8b\u52a1\u8868\uff0c\u8bed\u53e5\u5931\u8d25\u5c06\u4f1a\u5bfc\u81f4\u6240\u6709\u6267\u884c\u7684\u8bed\u53e5\u56de\u6eda\u3002\u89e6\u53d1\u5668\u5931\u8d25\u5bfc\u81f3\u8bed\u53e5\u5931\u8d25\uff0c\u6240\u4ee5\u89e6\u53d1\u5668\u5931\u8d25\u540c\u6837\u5bfc\u81f4\u56de\u6eda\u3002\u5bf9\u4e8e\u975e\u4e8b\u52a1\u8868\uff0c\u4e0d\u80fd\u6267\u884c\u56de\u6eda\uff0c\u6240\u4ee5\u867d\u7136\u8bed\u53e5\u5931\u8d25\uff0c\u4f46\u5df2\u7ecf\u751f\u6548\u7684\u8bed\u53e5\u4e5f\u4e0d\u4f1a\u56de\u6eda\u3002<\/li>\n<\/ul>\n<p>\u89e6\u53d1\u5668\u80fd\u76f4\u63a5\u901a\u8fc7\u8868\u540d\u5f15\u7528\u67d0\u4e00\u4e2a\u8868\uff0c\u4f8b\u5982\uff1a<\/p>\n<pre class=\"programlisting line-numbers language-sql\"><code class=\" language-sql\"><span class=\"token keyword\">CREATE<\/span> <span class=\"token keyword\">TABLE<\/span> test1<span class=\"token punctuation\">(<\/span>a1 <span class=\"token datatype\">INT<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token keyword\">CREATE<\/span> <span class=\"token keyword\">TABLE<\/span> test2<span class=\"token punctuation\">(<\/span>a2 <span class=\"token datatype\">INT<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token keyword\">CREATE<\/span> <span class=\"token keyword\">TABLE<\/span> test3<span class=\"token punctuation\">(<\/span>a3 <span class=\"token datatype\">INT<\/span> <span class=\"token operator\">NOT<\/span> <span class=\"token boolean\">NULL<\/span> <span class=\"token keyword\">AUTO_INCREMENT<\/span> <span class=\"token keyword\">PRIMARY<\/span> <span class=\"token keyword\">KEY<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token keyword\">CREATE<\/span> <span class=\"token keyword\">TABLE<\/span> test4<span class=\"token punctuation\">(<\/span>\r\n  a4 <span class=\"token datatype\">INT<\/span> <span class=\"token operator\">NOT<\/span> <span class=\"token boolean\">NULL<\/span> <span class=\"token keyword\">AUTO_INCREMENT<\/span> <span class=\"token keyword\">PRIMARY<\/span> <span class=\"token keyword\">KEY<\/span><span class=\"token punctuation\">,<\/span>\r\n  b4 <span class=\"token datatype\">INT<\/span> <span class=\"token keyword\">DEFAULT<\/span> <span class=\"token number\">0<\/span>\r\n<span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n\r\n<span class=\"token keyword\">delimiter<\/span> <span class=\"token operator\">|<\/span>\r\n\r\n<span class=\"token keyword\">CREATE<\/span> <span class=\"token keyword\">TRIGGER<\/span> testref <span class=\"token keyword\">BEFORE<\/span> <span class=\"token keyword\">INSERT<\/span> <span class=\"token keyword\">ON<\/span> test1\r\n  <span class=\"token keyword\">FOR<\/span> <span class=\"token keyword\">EACH<\/span> <span class=\"token keyword\">ROW<\/span>\r\n  <span class=\"token keyword\">BEGIN<\/span>\r\n    <span class=\"token keyword\">INSERT<\/span> <span class=\"token keyword\">INTO<\/span> test2 <span class=\"token keyword\">SET<\/span> a2 <span class=\"token operator\">=<\/span> <span class=\"token keyword\">NEW<\/span><span class=\"token punctuation\">.<\/span>a1<span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token keyword\">DELETE<\/span> <span class=\"token keyword\">FROM<\/span> test3 <span class=\"token keyword\">WHERE<\/span> a3 <span class=\"token operator\">=<\/span> <span class=\"token keyword\">NEW<\/span><span class=\"token punctuation\">.<\/span>a1<span class=\"token punctuation\">;<\/span>\r\n    <span class=\"token keyword\">UPDATE<\/span> test4 <span class=\"token keyword\">SET<\/span> b4 <span class=\"token operator\">=<\/span> b4 <span class=\"token operator\">+<\/span> <span class=\"token number\">1<\/span> <span class=\"token keyword\">WHERE<\/span> a4 <span class=\"token operator\">=<\/span> <span class=\"token keyword\">NEW<\/span><span class=\"token punctuation\">.<\/span>a1<span class=\"token punctuation\">;<\/span>\r\n  <span class=\"token keyword\">END<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token operator\">|<\/span>\r\n\r\n<span class=\"token keyword\">delimiter<\/span> <span class=\"token punctuation\">;<\/span>\r\n\r\n<span class=\"token keyword\">INSERT<\/span> <span class=\"token keyword\">INTO<\/span> test3 <span class=\"token punctuation\">(<\/span>a3<span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">VALUES<\/span>\r\n  <span class=\"token punctuation\">(<\/span><span class=\"token boolean\">NULL<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token boolean\">NULL<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token boolean\">NULL<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token boolean\">NULL<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token boolean\">NULL<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span>\r\n  <span class=\"token punctuation\">(<\/span><span class=\"token boolean\">NULL<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token boolean\">NULL<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token boolean\">NULL<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token boolean\">NULL<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token boolean\">NULL<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n\r\n<span class=\"token keyword\">INSERT<\/span> <span class=\"token keyword\">INTO<\/span> test4 <span class=\"token punctuation\">(<\/span>a4<span class=\"token punctuation\">)<\/span> <span class=\"token keyword\">VALUES<\/span>\r\n  <span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">0<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span><\/code><\/pre>\n<p>\u5047\u8bbe\u4f60\u73b0\u5728\u63d2\u5165\u4e0b\u9762\u7684\u6570\u636e\u5230test1\u4e2d\uff1a<\/p>\n<pre class=\"programlisting line-numbers  language-sql\"><code class=\" language-sql\"><span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">INSERT<\/span> <span class=\"token keyword\">INTO<\/span> test1 <span class=\"token keyword\">VALUES<\/span> \r\n       <span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">3<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">7<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">1<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">8<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">4<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">,<\/span> <span class=\"token punctuation\">(<\/span><span class=\"token number\">4<\/span><span class=\"token punctuation\">)<\/span><span class=\"token punctuation\">;<\/span>\r\n<span class=\"token output\">Query OK, 8 rows affected (0.01 sec)<\/span>\r\n<span class=\"token output\">Records: 8  Duplicates: 0  Warnings: 0<\/span><\/code><\/pre>\n<p>\u90a3\u4e48\uff0ctest1,test2,test3,test4\u51e0\u4e2a\u8868\u4e2d\u7684\u503c\u53d8\u5316\u5982\u4e0b\uff1a<\/p>\n<pre class=\"programlisting line-numbers  language-sql\"><code class=\" language-sql\"><span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">SELECT<\/span> <span class=\"token operator\">*<\/span> <span class=\"token keyword\">FROM<\/span> test1<span class=\"token punctuation\">;<\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span> a1   <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>    1 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>    3 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>    1 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>    7 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>    1 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>    8 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>    4 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>    4 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span>\r\n<span class=\"token output\">8 rows in set (0.00 sec)<\/span>\r\n\r\n<span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">SELECT<\/span> <span class=\"token operator\">*<\/span> <span class=\"token keyword\">FROM<\/span> test2<span class=\"token punctuation\">;<\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span> a2   <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>    1 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>    3 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>    1 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>    7 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>    1 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>    8 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>    4 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>    4 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span>\r\n<span class=\"token output\">8 rows in set (0.00 sec)<\/span>\r\n\r\n<span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">SELECT<\/span> <span class=\"token operator\">*<\/span> <span class=\"token keyword\">FROM<\/span> test3<span class=\"token punctuation\">;<\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span> a3 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>  2 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>  5 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>  6 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>  9 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span> 10 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span>\r\n<span class=\"token output\">5 rows in set (0.00 sec)<\/span>\r\n\r\n<span class=\"token prompt\">mysql&gt;<\/span> <span class=\"token keyword\">SELECT<\/span> <span class=\"token operator\">*<\/span> <span class=\"token keyword\">FROM<\/span> test4<span class=\"token punctuation\">;<\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span> a4 <span class=\"token punctuation\">|<\/span> b4   <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>  1 <span class=\"token punctuation\">|<\/span>    3 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>  2 <span class=\"token punctuation\">|<\/span>    0 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>  3 <span class=\"token punctuation\">|<\/span>    1 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>  4 <span class=\"token punctuation\">|<\/span>    2 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>  5 <span class=\"token punctuation\">|<\/span>    0 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>  6 <span class=\"token punctuation\">|<\/span>    0 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>  7 <span class=\"token punctuation\">|<\/span>    1 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>  8 <span class=\"token punctuation\">|<\/span>    1 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span>  9 <span class=\"token punctuation\">|<\/span>    0 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">|<\/span> 10 <span class=\"token punctuation\">|<\/span>    0 <span class=\"token punctuation\">|<\/span><\/span>\r\n<span class=\"token output\"><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">-<\/span><span class=\"token punctuation\">+<\/span><\/span>\r\n<span class=\"token output\">10 rows in set (0.00 sec)<\/span><\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\u521b\u5efa\u548c\u5220\u9664\u89e6\u53d1\u5668\u4f7f\u7528CREATE TRIGGER\u6216DROP TRIGER\u8bed\u53e5\uff1a CREATE [DEFINER = { user | CURRENT_USER &#8230;<\/p>\n<p class=\"read-more\"><a class=\"btn btn-default\" href=\"https:\/\/www.5x44.cn\/?p=1018\"> Read More<span class=\"screen-reader-text\">  Read More<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[37],"tags":[],"class_list":["post-1018","post","type-post","status-publish","format-standard","hentry","category-mysql"],"_links":{"self":[{"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/posts\/1018","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1018"}],"version-history":[{"count":7,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/posts\/1018\/revisions"}],"predecessor-version":[{"id":1025,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=\/wp\/v2\/posts\/1018\/revisions\/1025"}],"wp:attachment":[{"href":"https:\/\/www.5x44.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1018"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1018"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.5x44.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1018"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}