{"id":76410,"date":"2024-10-16T06:26:16","date_gmt":"2024-10-15T22:26:16","guid":{"rendered":"https:\/\/server.hk\/cnblog\/76410\/"},"modified":"2024-10-16T06:26:16","modified_gmt":"2024-10-15T22:26:16","slug":"mysql%e6%95%b8%e6%93%9a%e5%ba%ab%e6%9f%a5%e8%a9%a2%e7%b7%b4%e7%bf%92%e9%a1%8c%e7%b2%be%e9%81%b8-mysql%e6%95%b8%e6%93%9a%e5%ba%ab%e6%9f%a5%e8%a9%a2%e7%bf%92%e9%a1%8c","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/76410\/","title":{"rendered":"MySQL\u6578\u64da\u5eab\u67e5\u8a62\u7df4\u7fd2\u984c\u7cbe\u9078 (MySQL\u6578\u64da\u5eab\u67e5\u8a62\u7fd2\u984c)"},"content":{"rendered":"<h1 id=\"mysql%e6%95%b8%e6%93%9a%e5%ba%ab%e6%9f%a5%e8%a9%a2%e7%b7%b4%e7%bf%92%e9%a1%8c%e7%b2%be%e9%81%b8-BFxQWBjqBb\">MySQL\u6578\u64da\u5eab\u67e5\u8a62\u7df4\u7fd2\u984c\u7cbe\u9078<\/h1>\n<p>MySQL\u662f\u4e00\u7a2e\u6d41\u884c\u7684\u958b\u6e90\u95dc\u806f\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u5ee3\u6cdb\u61c9\u7528\u65bc\u5404\u7a2e\u7db2\u7ad9\u548c\u61c9\u7528\u7a0b\u5e8f\u4e2d\u3002\u5c0d\u65bc\u958b\u767c\u8005\u548c\u6578\u64da\u5206\u6790\u5e2b\u4f86\u8aaa\uff0c\u719f\u7df4\u638c\u63e1MySQL\u67e5\u8a62\u8a9e\u8a00\u662f\u5fc5\u4e0d\u53ef\u5c11\u7684\u3002\u672c\u6587\u5c07\u4ecb\u7d39\u4e00\u4e9b\u7cbe\u9078\u7684MySQL\u67e5\u8a62\u7df4\u7fd2\u984c\uff0c\u5e6b\u52a9\u8b80\u8005\u63d0\u5347\u5176\u6578\u64da\u5eab\u67e5\u8a62\u6280\u80fd\u3002<\/p>\n<h2 id=\"%e5%9f%ba%e7%a4%8e%e6%9f%a5%e8%a9%a2%e7%b7%b4%e7%bf%92-BFxQWBjqBb\">\u57fa\u790e\u67e5\u8a62\u7df4\u7fd2<\/h2>\n<p>\u5728\u958b\u59cb\u9032\u884c\u8907\u96dc\u67e5\u8a62\u4e4b\u524d\uff0c\u9996\u5148\u9700\u8981\u638c\u63e1\u57fa\u672c\u7684\u67e5\u8a62\u8a9e\u6cd5\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u57fa\u790e\u67e5\u8a62\u7684\u7df4\u7fd2\u984c\uff1a<\/p>\n<ul>\n<li><strong>\u984c\u76ee1\uff1a<\/strong>\u5f9e\u540d\u70ba\u201cemployees\u201d\u7684\u8868\u4e2d\u9078\u64c7\u6240\u6709\u54e1\u5de5\u7684\u59d3\u540d\u548c\u5de5\u865f\u3002<\/li>\n<pre><code>SELECT employee_id, employee_name FROM employees;<\/code><\/pre>\n<li><strong>\u984c\u76ee2\uff1a<\/strong>\u67e5\u8a62\u201cproducts\u201d\u8868\u4e2d\u6240\u6709\u50f9\u683c\u9ad8\u65bc100\u7684\u7522\u54c1\u540d\u7a31\u548c\u50f9\u683c\u3002<\/li>\n<pre><code>SELECT product_name, price FROM products WHERE price &gt; 100;<\/code><\/pre>\n<\/ul>\n<h2 id=\"%e6%a2%9d%e4%bb%b6%e6%9f%a5%e8%a9%a2%e7%b7%b4%e7%bf%92-BFxQWBjqBb\">\u689d\u4ef6\u67e5\u8a62\u7df4\u7fd2<\/h2>\n<p>\u5728\u5be6\u969b\u61c9\u7528\u4e2d\uff0c\u7d93\u5e38\u9700\u8981\u6839\u64da\u7279\u5b9a\u689d\u4ef6\u7be9\u9078\u6578\u64da\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u689d\u4ef6\u67e5\u8a62\u7684\u7df4\u7fd2\u984c\uff1a<\/p>\n<ul>\n<li><strong>\u984c\u76ee3\uff1a<\/strong>\u67e5\u8a62\u201corders\u201d\u8868\u4e2d\u6240\u6709\u57282023\u5e74\u5167\u4e0b\u7684\u8a02\u55ae\u3002<\/li>\n<pre><code>SELECT * FROM orders WHERE order_date BETWEEN '2023-01-01' AND '2023-12-31';<\/code><\/pre>\n<li><strong>\u984c\u76ee4\uff1a<\/strong>\u5f9e\u201ccustomers\u201d\u8868\u4e2d\u67e5\u8a62\u4f86\u81ea\u201c\u9999\u6e2f\u201d\u7684\u6240\u6709\u5ba2\u6236\u3002<\/li>\n<pre><code>SELECT * FROM customers WHERE city = '\u9999\u6e2f';<\/code><\/pre>\n<\/ul>\n<h2 id=\"%e8%81%9a%e5%90%88%e5%87%bd%e6%95%b8%e7%b7%b4%e7%bf%92-BFxQWBjqBb\">\u805a\u5408\u51fd\u6578\u7df4\u7fd2<\/h2>\n<p>\u805a\u5408\u51fd\u6578\u53ef\u4ee5\u5e6b\u52a9\u6211\u5011\u5c0d\u6578\u64da\u9032\u884c\u7d71\u8a08\u5206\u6790\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u4f7f\u7528\u805a\u5408\u51fd\u6578\u7684\u7df4\u7fd2\u984c\uff1a<\/p>\n<ul>\n<li><strong>\u984c\u76ee5\uff1a<\/strong>\u8a08\u7b97\u201csales\u201d\u8868\u4e2d\u6240\u6709\u92b7\u552e\u8a18\u9304\u7684\u7e3d\u92b7\u552e\u984d\u3002<\/li>\n<pre><code>SELECT SUM(sale_amount) AS total_sales FROM sales;<\/code><\/pre>\n<li><strong>\u984c\u76ee6\uff1a<\/strong>\u67e5\u8a62\u201cemployees\u201d\u8868\u4e2d\u6bcf\u500b\u90e8\u9580\u7684\u54e1\u5de5\u6578\u91cf\u3002<\/li>\n<pre><code>SELECT department_id, COUNT(*) AS employee_count FROM employees GROUP BY department_id;<\/code><\/pre>\n<\/ul>\n<h2 id=\"%e8%81%af%e6%8e%a5%e6%9f%a5%e8%a9%a2%e7%b7%b4%e7%bf%92-BFxQWBjqBb\">\u806f\u63a5\u67e5\u8a62\u7df4\u7fd2<\/h2>\n<p>\u806f\u63a5\u67e5\u8a62\u662f\u6578\u64da\u5eab\u4e2d\u975e\u5e38\u91cd\u8981\u7684\u4e00\u90e8\u5206\uff0c\u80fd\u5920\u5c07\u591a\u500b\u8868\u4e2d\u7684\u6578\u64da\u7d50\u5408\u8d77\u4f86\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u806f\u63a5\u67e5\u8a62\u7684\u7df4\u7fd2\u984c\uff1a<\/p>\n<ul>\n<li><strong>\u984c\u76ee7\uff1a<\/strong>\u67e5\u8a62\u201cemployees\u201d\u8868\u548c\u201cdepartments\u201d\u8868\u4e2d\u6240\u6709\u54e1\u5de5\u53ca\u5176\u6240\u5c6c\u90e8\u9580\u7684\u540d\u7a31\u3002<\/li>\n<pre><code>SELECT e.employee_name, d.department_name \nFROM employees e \nJOIN departments d ON e.department_id = d.department_id;<\/code><\/pre>\n<li><strong>\u984c\u76ee8\uff1a<\/strong>\u67e5\u8a62\u201corders\u201d\u8868\u548c\u201ccustomers\u201d\u8868\u4e2d\u6240\u6709\u8a02\u55ae\u53ca\u5176\u5c0d\u61c9\u5ba2\u6236\u7684\u59d3\u540d\u3002<\/li>\n<pre><code>SELECT o.order_id, c.customer_name \nFROM orders o \nJOIN customers c ON o.customer_id = c.customer_id;<\/code><\/pre>\n<\/ul>\n<h2 id=\"%e5%ad%90%e6%9f%a5%e8%a9%a2%e7%b7%b4%e7%bf%92-BFxQWBjqBb\">\u5b50\u67e5\u8a62\u7df4\u7fd2<\/h2>\n<p>\u5b50\u67e5\u8a62\u662f\u4e00\u7a2e\u5f37\u5927\u7684\u67e5\u8a62\u65b9\u5f0f\uff0c\u53ef\u4ee5\u5728\u4e00\u500b\u67e5\u8a62\u4e2d\u5d4c\u5957\u53e6\u4e00\u500b\u67e5\u8a62\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5b50\u67e5\u8a62\u7684\u7df4\u7fd2\u984c\uff1a<\/p>\n<ul>\n<li><strong>\u984c\u76ee9\uff1a<\/strong>\u67e5\u8a62\u201cemployees\u201d\u8868\u4e2d\u5de5\u8cc7\u9ad8\u65bc\u5e73\u5747\u5de5\u8cc7\u7684\u54e1\u5de5\u59d3\u540d\u3002<\/li>\n<pre><code>SELECT employee_name \nFROM employees \nWHERE salary &gt; (SELECT AVG(salary) FROM employees);<\/code><\/pre>\n<li><strong>\u984c\u76ee10\uff1a<\/strong>\u67e5\u8a62\u201cproducts\u201d\u8868\u4e2d\u50f9\u683c\u9ad8\u65bc\u201ccategories\u201d\u8868\u4e2d\u6240\u6709\u985e\u5225\u7684\u5e73\u5747\u50f9\u683c\u7684\u7522\u54c1\u540d\u7a31\u3002<\/li>\n<pre><code>SELECT product_name \nFROM products \nWHERE price &gt; (SELECT AVG(price) FROM products GROUP BY category_id);<\/code><\/pre>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-BFxQWBjqBb\">\u7e3d\u7d50<\/h2>\n<p>\u901a\u904e\u4ee5\u4e0a\u7684\u7df4\u7fd2\u984c\uff0c\u8b80\u8005\u53ef\u4ee5\u9010\u6b65\u63d0\u5347\u81ea\u5df1\u7684MySQL\u67e5\u8a62\u6280\u80fd\uff0c\u5f9e\u57fa\u790e\u67e5\u8a62\u5230\u8907\u96dc\u7684\u806f\u63a5\u548c\u5b50\u67e5\u8a62\uff0c\u9019\u4e9b\u90fd\u662f\u65e5\u5e38\u6578\u64da\u5eab\u64cd\u4f5c\u4e2d\u5e38\u898b\u7684\u9700\u6c42\u3002\u7121\u8ad6\u662f\u958b\u767c\u8005\u9084\u662f\u6578\u64da\u5206\u6790\u5e2b\uff0c\u638c\u63e1\u9019\u4e9b\u67e5\u8a62\u6280\u5de7\u90fd\u5c07\u5927\u5927\u63d0\u9ad8\u5de5\u4f5c\u6548\u7387\u3002<\/p>\n<p>\u5982\u679c\u60a8\u9700\u8981\u7a69\u5b9a\u7684\u6578\u64da\u5eab\u652f\u6301\uff0c\u8003\u616e\u4f7f\u7528<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u670d\u52d9\uff0c\u9019\u5c07\u70ba\u60a8\u7684\u61c9\u7528\u63d0\u4f9b\u5f37\u5927\u7684\u5f8c\u7aef\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u7cbe\u9078MySQL\u6578\u64da\u5eab\u67e5\u8a62\u7df4\u7fd2\u984c\uff0c\u5e6b\u52a9\u63d0\u5347\u67e5\u8a62\u6280\u5de7\uff0c\u9069\u5408\u521d\u5b78\u8005\u8207\u9032\u968e\u8005\uff0c\u5feb\u901f\u638c\u63e1\u6578\u64da\u5eab\u64cd\u4f5c\u3002<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-76410","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/76410","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=76410"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/76410\/revisions"}],"predecessor-version":[{"id":76411,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/76410\/revisions\/76411"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=76410"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=76410"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=76410"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}