{"id":143935,"date":"2024-11-01T02:29:22","date_gmt":"2024-10-31T18:29:22","guid":{"rendered":"https:\/\/server.hk\/cnblog\/143935\/"},"modified":"2024-11-01T02:29:22","modified_gmt":"2024-10-31T18:29:22","slug":"sql-%e6%95%b8%e6%93%9a%e5%ba%ab%e7%b7%a8%e7%a8%8b%e8%80%83%e8%a9%a6%e8%a9%a6%e9%a1%8c%e8%a7%a3%e6%9e%90-30-%e9%81%93%e9%a1%8c%e6%a0%bc%e5%b1%80%e5%a4%a7%e9%96%8b%e7%9c%bc%e7%95%8c-sql-%e6%95%b8","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/143935\/","title":{"rendered":"SQL \u6578\u64da\u5eab\u7de8\u7a0b\u8003\u8a66\u8a66\u984c\u89e3\u6790 | 30 \u9053\u984c\u683c\u5c40\u5927\u958b\u773c\u754c (sql \u6578\u64da\u5eab\u7684\u7de8\u7a0b\u8003\u8a66\u8a66\u984c)"},"content":{"rendered":"<h1 id=\"sql-%e6%95%b8%e6%93%9a%e5%ba%ab%e7%b7%a8%e7%a8%8b%e8%80%83%e8%a9%a6%e8%a9%a6%e9%a1%8c%e8%a7%a3%e6%9e%90-30-%e9%81%93%e9%a1%8c%e6%a0%bc%e5%b1%80%e5%a4%a7%e9%96%8b%e7%9c%bc%e7%95%8c-VLMBplipdT\">SQL \u6578\u64da\u5eab\u7de8\u7a0b\u8003\u8a66\u8a66\u984c\u89e3\u6790 | 30 \u9053\u984c\u683c\u5c40\u5927\u958b\u773c\u754c<\/h1>\n<p>\u5728\u7576\u4eca\u6578\u64da\u9a45\u52d5\u7684\u4e16\u754c\u4e2d\uff0cSQL\uff08\u7d50\u69cb\u5316\u67e5\u8a62\u8a9e\u8a00\uff09\u5df2\u6210\u70ba\u6578\u64da\u5eab\u7ba1\u7406\u548c\u64cd\u4f5c\u7684\u6838\u5fc3\u5de5\u5177\u3002\u7121\u8ad6\u662f\u4f01\u696d\u9084\u662f\u500b\u4eba\u958b\u767c\u8005\uff0c\u638c\u63e1SQL\u90fd\u662f\u4e00\u9805\u5fc5\u5099\u6280\u80fd\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e30\u9053SQL\u6578\u64da\u5eab\u7de8\u7a0b\u8003\u8a66\u8a66\u984c\uff0c\u5e6b\u52a9\u8b80\u8005\u66f4\u597d\u5730\u7406\u89e3SQL\u7684\u61c9\u7528\u53ca\u5176\u5728\u5be6\u969b\u5de5\u4f5c\u4e2d\u7684\u91cd\u8981\u6027\u3002<\/p>\n<h2 id=\"sql-%e5%9f%ba%e7%a4%8e%e7%9f%a5%e8%ad%98-VLMBplipdT\">SQL \u57fa\u790e\u77e5\u8b58<\/h2>\n<p>\u5728\u9032\u5165\u5177\u9ad4\u7684\u8003\u8a66\u984c\u76ee\u4e4b\u524d\uff0c\u6211\u5011\u9996\u5148\u56de\u9867\u4e00\u4e0bSQL\u7684\u57fa\u672c\u6982\u5ff5\u3002SQL\u662f\u4e00\u7a2e\u7528\u65bc\u7ba1\u7406\u95dc\u4fc2\u578b\u6578\u64da\u5eab\u7684\u6a19\u6e96\u8a9e\u8a00\uff0c\u4e3b\u8981\u7528\u65bc\u67e5\u8a62\u3001\u63d2\u5165\u3001\u66f4\u65b0\u548c\u522a\u9664\u6578\u64da\u3002SQL\u7684\u57fa\u672c\u8a9e\u6cd5\u5305\u62ec\uff1a<\/p>\n<ul>\n<li><code>SELECT<\/code>\uff1a\u7528\u65bc\u67e5\u8a62\u6578\u64da\u3002<\/li>\n<li><code>INSERT<\/code>\uff1a\u7528\u65bc\u63d2\u5165\u65b0\u6578\u64da\u3002<\/li>\n<li><code>UPDATE<\/code>\uff1a\u7528\u65bc\u66f4\u65b0\u73fe\u6709\u6578\u64da\u3002<\/li>\n<li><code>DELETE<\/code>\uff1a\u7528\u65bc\u522a\u9664\u6578\u64da\u3002<\/li>\n<\/ul>\n<h2 id=\"%e8%80%83%e8%a9%a6%e9%a1%8c%e7%9b%ae%e8%a7%a3%e6%9e%90-VLMBplipdT\">\u8003\u8a66\u984c\u76ee\u89e3\u6790<\/h2>\n<p>\u4ee5\u4e0b\u662f30\u9053SQL\u7de8\u7a0b\u8003\u8a66\u8a66\u984c\u7684\u89e3\u6790\uff0c\u9019\u4e9b\u984c\u76ee\u6db5\u84cb\u4e86\u5f9e\u57fa\u790e\u5230\u9032\u968e\u7684\u5404\u7a2e\u77e5\u8b58\u9ede\u3002<\/p>\n<h3 id=\"1-%e5%9f%ba%e6%9c%ac%e6%9f%a5%e8%a9%a2-VLMBplipdT\">1. \u57fa\u672c\u67e5\u8a62<\/h3>\n<p>\u984c\u76ee\uff1a\u64b0\u5beb\u4e00\u500b\u67e5\u8a62\uff0c\u5f9e\u201cemployees\u201d\u8868\u4e2d\u9078\u64c7\u6240\u6709\u54e1\u5de5\u7684\u59d3\u540d\u548c\u5de5\u8cc7\u3002<\/p>\n<pre><code>SELECT name, salary FROM employees;<\/code><\/pre>\n<h3 id=\"2-%e6%a2%9d%e4%bb%b6%e6%9f%a5%e8%a9%a2-VLMBplipdT\">2. \u689d\u4ef6\u67e5\u8a62<\/h3>\n<p>\u984c\u76ee\uff1a\u67e5\u8a62\u5de5\u8cc7\u9ad8\u65bc50000\u7684\u54e1\u5de5\u59d3\u540d\u3002<\/p>\n<pre><code>SELECT name FROM employees WHERE salary &gt; 50000;<\/code><\/pre>\n<h3 id=\"3-%e6%8e%92%e5%ba%8f%e6%9f%a5%e8%a9%a2-VLMBplipdT\">3. \u6392\u5e8f\u67e5\u8a62<\/h3>\n<p>\u984c\u76ee\uff1a\u67e5\u8a62\u6240\u6709\u54e1\u5de5\u7684\u59d3\u540d\uff0c\u4e26\u6309\u5de5\u8cc7\u5f9e\u9ad8\u5230\u4f4e\u6392\u5e8f\u3002<\/p>\n<pre><code>SELECT name FROM employees ORDER BY salary DESC;<\/code><\/pre>\n<h3 id=\"4-%e8%81%9a%e5%90%88%e5%87%bd%e6%95%b8-VLMBplipdT\">4. \u805a\u5408\u51fd\u6578<\/h3>\n<p>\u984c\u76ee\uff1a\u8a08\u7b97\u201cemployees\u201d\u8868\u4e2d\u6240\u6709\u54e1\u5de5\u7684\u5e73\u5747\u5de5\u8cc7\u3002<\/p>\n<pre><code>SELECT AVG(salary) FROM employees;<\/code><\/pre>\n<h3 id=\"5-%e5%88%86%e7%b5%84%e6%9f%a5%e8%a9%a2-VLMBplipdT\">5. \u5206\u7d44\u67e5\u8a62<\/h3>\n<p>\u984c\u76ee\uff1a\u67e5\u8a62\u6bcf\u500b\u90e8\u9580\u7684\u54e1\u5de5\u6578\u91cf\u3002<\/p>\n<pre><code>SELECT department, COUNT(*) FROM employees GROUP BY department;<\/code><\/pre>\n<h3 id=\"6-%e9%80%a3%e6%8e%a5%e6%9f%a5%e8%a9%a2-VLMBplipdT\">6. \u9023\u63a5\u67e5\u8a62<\/h3>\n<p>\u984c\u76ee\uff1a\u67e5\u8a62\u6bcf\u4f4d\u54e1\u5de5\u53ca\u5176\u6240\u5c6c\u90e8\u9580\u7684\u540d\u7a31\u3002<\/p>\n<pre><code>SELECT e.name, d.department_name \nFROM employees e \nJOIN departments d ON e.department_id = d.id;<\/code><\/pre>\n<h3 id=\"7-%e5%ad%90%e6%9f%a5%e8%a9%a2-VLMBplipdT\">7. \u5b50\u67e5\u8a62<\/h3>\n<p>\u984c\u76ee\uff1a\u67e5\u8a62\u5de5\u8cc7\u9ad8\u65bc\u90e8\u9580\u5e73\u5747\u5de5\u8cc7\u7684\u54e1\u5de5\u59d3\u540d\u3002<\/p>\n<pre><code>SELECT name FROM employees \nWHERE salary &gt; (SELECT AVG(salary) FROM employees WHERE department_id = employees.department_id);<\/code><\/pre>\n<h3 id=\"8-%e6%9b%b4%e6%96%b0%e6%95%b8%e6%93%9a-VLMBplipdT\">8. \u66f4\u65b0\u6578\u64da<\/h3>\n<p>\u984c\u76ee\uff1a\u5c07\u6240\u6709\u54e1\u5de5\u7684\u5de5\u8cc7\u63d0\u9ad810%\u3002<\/p>\n<pre><code>UPDATE employees SET salary = salary * 1.1;<\/code><\/pre>\n<h3 id=\"9-%e5%88%aa%e9%99%a4%e6%95%b8%e6%93%9a-VLMBplipdT\">9. \u522a\u9664\u6578\u64da<\/h3>\n<p>\u984c\u76ee\uff1a\u522a\u9664\u6240\u6709\u5de5\u8cc7\u4f4e\u65bc30000\u7684\u54e1\u5de5\u3002<\/p>\n<pre><code>DELETE FROM employees WHERE salary &lt; 30000;<\/code><\/pre>\n<h3 id=\"10-%e6%95%b8%e6%93%9a%e6%8f%92%e5%85%a5-VLMBplipdT\">10. \u6578\u64da\u63d2\u5165<\/h3>\n<p>\u984c\u76ee\uff1a\u5411\u201cemployees\u201d\u8868\u4e2d\u63d2\u5165\u4e00\u540d\u65b0\u54e1\u5de5\u7684\u6578\u64da\u3002<\/p>\n<pre><code>INSERT INTO employees (name, salary, department_id) VALUES ('John Doe', 45000, 1);<\/code><\/pre>\n<h2 id=\"%e9%80%b2%e9%9a%8e%e9%a1%8c%e7%9b%ae-VLMBplipdT\">\u9032\u968e\u984c\u76ee<\/h2>\n<p>\u9664\u4e86\u57fa\u672c\u7684SQL\u64cd\u4f5c\uff0c\u9084\u6709\u4e00\u4e9b\u9032\u968e\u7684\u984c\u76ee\u53ef\u4ee5\u5e6b\u52a9\u8003\u751f\u63d0\u5347\u6280\u80fd\uff1a<\/p>\n<h3 id=\"11-%e4%bd%bf%e7%94%a8%e7%aa%97%e5%8f%a3%e5%87%bd%e6%95%b8-VLMBplipdT\">11. \u4f7f\u7528\u7a97\u53e3\u51fd\u6578<\/h3>\n<p>\u984c\u76ee\uff1a\u67e5\u8a62\u6bcf\u4f4d\u54e1\u5de5\u7684\u5de5\u8cc7\u53ca\u5176\u5728\u90e8\u9580\u4e2d\u7684\u6392\u540d\u3002<\/p>\n<pre><code>SELECT name, salary, RANK() OVER (PARTITION BY department_id ORDER BY salary DESC) as rank \nFROM employees;<\/code><\/pre>\n<h3 id=\"12-%e4%ba%8b%e5%8b%99%e8%99%95%e7%90%86-VLMBplipdT\">12. \u4e8b\u52d9\u8655\u7406<\/h3>\n<p>\u984c\u76ee\uff1a\u63cf\u8ff0\u5982\u4f55\u4f7f\u7528\u4e8b\u52d9\u4f86\u78ba\u4fdd\u6578\u64da\u7684\u4e00\u81f4\u6027\u3002<\/p>\n<p>\u7b54\uff1a\u4f7f\u7528<code>BEGIN TRANSACTION<\/code>\u958b\u59cb\u4e8b\u52d9\uff0c\u7136\u5f8c\u57f7\u884c\u591a\u500bSQL\u8a9e\u53e5\uff0c\u6700\u5f8c\u4f7f\u7528<code>COMMIT<\/code>\u63d0\u4ea4\u6216<code>ROLLBACK<\/code>\u56de\u6efe\u3002<\/p>\n<h3 id=\"13-%e6%95%b8%e6%93%9a%e5%ba%ab%e8%a8%ad%e8%a8%88-VLMBplipdT\">13. \u6578\u64da\u5eab\u8a2d\u8a08<\/h3>\n<p>\u984c\u76ee\uff1a\u8a2d\u8a08\u4e00\u500b\u7c21\u55ae\u7684\u6578\u64da\u5eab\u67b6\u69cb\uff0c\u5305\u62ec\u54e1\u5de5\u3001\u90e8\u9580\u548c\u9805\u76ee\u8868\u3002<\/p>\n<p>\u7b54\uff1a\u53ef\u4ee5\u8a2d\u8a08\u4e09\u500b\u8868\uff0c\u5206\u5225\u70ba\u201cemployees\u201d\u3001\u201cdepartments\u201d\u548c\u201cprojects\u201d\uff0c\u4e26\u901a\u904e\u5916\u9375\u95dc\u806f\u3002<\/p>\n<h3 id=\"14-%e6%80%a7%e8%83%bd%e5%84%aa%e5%8c%96-VLMBplipdT\">14. \u6027\u80fd\u512a\u5316<\/h3>\n<p>\u984c\u76ee\uff1a\u5982\u4f55\u512a\u5316SQL\u67e5\u8a62\u6027\u80fd\uff1f<\/p>\n<p>\u7b54\uff1a\u53ef\u4ee5\u901a\u904e\u5efa\u7acb\u7d22\u5f15\u3001\u907f\u514d\u4f7f\u7528SELECT *\u3001\u4ee5\u53ca\u512a\u5316\u67e5\u8a62\u689d\u4ef6\u4f86\u63d0\u9ad8\u6027\u80fd\u3002<\/p>\n<h3 id=\"15-%e6%95%b8%e6%93%9a%e5%ae%8c%e6%95%b4%e6%80%a7-VLMBplipdT\">15. \u6578\u64da\u5b8c\u6574\u6027<\/h3>\n<p>\u984c\u76ee\uff1a\u5982\u4f55\u78ba\u4fdd\u6578\u64da\u7684\u5b8c\u6574\u6027\uff1f<\/p>\n<p>\u7b54\uff1a\u53ef\u4ee5\u4f7f\u7528\u4e3b\u9375\u3001\u5916\u9375\u548c\u7d04\u675f\u689d\u4ef6\u4f86\u78ba\u4fdd\u6578\u64da\u7684\u5b8c\u6574\u6027\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-VLMBplipdT\">\u7e3d\u7d50<\/h2>\n<p>\u638c\u63e1SQL\u6578\u64da\u5eab\u7de8\u7a0b\u4e0d\u50c5\u5c0d\u65bc\u8003\u8a66\u81f3\u95dc\u91cd\u8981\uff0c\u66f4\u662f\u8077\u5834\u4e2d\u4e0d\u53ef\u6216\u7f3a\u7684\u6280\u80fd\u3002\u901a\u904e\u4ee5\u4e0a30\u9053\u984c\u76ee\u7684\u89e3\u6790\uff0c\u8b80\u8005\u53ef\u4ee5\u66f4\u6df1\u5165\u5730\u7406\u89e3SQL\u7684\u61c9\u7528\u53ca\u5176\u5728\u6578\u64da\u7ba1\u7406\u4e2d\u7684\u91cd\u8981\u6027\u3002\u7121\u8ad6\u662f\u57fa\u790e\u67e5\u8a62\u9084\u662f\u9032\u968e\u64cd\u4f5c\uff0c\u719f\u7df4\u638c\u63e1SQL\u90fd\u80fd\u70ba\u60a8\u7684\u8077\u696d\u751f\u6daf\u589e\u6dfb\u52a9\u529b\u3002\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\uff0c\u8003\u616e\u4f7f\u7528<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u4f86\u642d\u5efa\u60a8\u7684\u6578\u64da\u5eab\u74b0\u5883\uff0c\u4eab\u53d7\u7a69\u5b9a\u548c\u9ad8\u6548\u7684\u670d\u52d9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d2230\u9053SQL\u6578\u64da\u5eab\u7de8\u7a0b\u8003\u8a66\u8a66\u984c\u89e3\u6790\uff0c\u63d0\u5347\u4f60\u7684\u7de8\u7a0b\u6280\u80fd\uff0c\u958b\u62d3\u601d\u7dad\uff0c\u52a9\u4f60\u5728\u8003\u8a66\u4e2d\u812b\u7a4e\u800c\u51fa\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-143935","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/143935","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=143935"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/143935\/revisions"}],"predecessor-version":[{"id":143936,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/143935\/revisions\/143936"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=143935"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=143935"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=143935"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}