{"id":168657,"date":"2024-11-06T14:44:34","date_gmt":"2024-11-06T06:44:34","guid":{"rendered":"https:\/\/server.hk\/cnblog\/168657\/"},"modified":"2024-11-06T14:44:35","modified_gmt":"2024-11-06T06:44:35","slug":"sybase-%e6%95%b8%e6%93%9a%e5%ba%ab%e5%87%bd%e6%95%b8%e5%85%a8%e4%bb%8b%e7%b4%b9","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/168657\/","title":{"rendered":"Sybase \u6578\u64da\u5eab\u51fd\u6578\u5168\u4ecb\u7d39"},"content":{"rendered":"<h1 id=\"sybase-%e6%95%b8%e6%93%9a%e5%ba%ab%e5%87%bd%e6%95%b8%e5%85%a8%e4%bb%8b%e7%b4%b9-UwqCLoQNgf\">Sybase \u6578\u64da\u5eab\u51fd\u6578\u5168\u4ecb\u7d39<\/h1>\n<p>Sybase \u6578\u64da\u5eab\u662f\u4e00\u500b\u529f\u80fd\u5f37\u5927\u7684\u95dc\u806f\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u5ee3\u6cdb\u61c9\u7528\u65bc\u4f01\u696d\u7d1a\u61c9\u7528\u4e2d\u3002\u5b83\u63d0\u4f9b\u4e86\u591a\u7a2e\u5167\u5efa\u51fd\u6578\uff0c\u5e6b\u52a9\u7528\u6236\u9032\u884c\u6578\u64da\u8655\u7406\u3001\u67e5\u8a62\u548c\u5206\u6790\u3002\u672c\u6587\u5c07\u5168\u9762\u4ecb\u7d39 Sybase \u6578\u64da\u5eab\u4e2d\u7684\u5404\u985e\u51fd\u6578\uff0c\u4e26\u63d0\u4f9b\u76f8\u61c9\u7684\u793a\u4f8b\uff0c\u4ee5\u4fbf\u8b80\u8005\u80fd\u5920\u66f4\u597d\u5730\u7406\u89e3\u548c\u61c9\u7528\u9019\u4e9b\u51fd\u6578\u3002<\/p>\n<h2 id=\"1-%e6%95%b8%e5%ad%b8%e5%87%bd%e6%95%b8-UwqCLoQNgf\">1. \u6578\u5b78\u51fd\u6578<\/h2>\n<p>Sybase \u63d0\u4f9b\u4e86\u591a\u7a2e\u6578\u5b78\u51fd\u6578\uff0c\u9019\u4e9b\u51fd\u6578\u53ef\u4ee5\u7528\u65bc\u6578\u503c\u8a08\u7b97\u548c\u6578\u64da\u5206\u6790\u3002\u5e38\u898b\u7684\u6578\u5b78\u51fd\u6578\u5305\u62ec\uff1a<\/p>\n<ul>\n<li><code>ABS(x)<\/code>\uff1a\u8fd4\u56de x \u7684\u7d55\u5c0d\u503c\u3002<\/li>\n<li><code>CEILING(x)<\/code>\uff1a\u8fd4\u56de\u5927\u65bc\u6216\u7b49\u65bc x \u7684\u6700\u5c0f\u6574\u6578\u3002<\/li>\n<li><code>FLOOR(x)<\/code>\uff1a\u8fd4\u56de\u5c0f\u65bc\u6216\u7b49\u65bc x \u7684\u6700\u5927\u6574\u6578\u3002<\/li>\n<li><code>ROUND(x, d)<\/code>\uff1a\u5c07 x \u56db\u6368\u4e94\u5165\u5230 d \u4f4d\u5c0f\u6578\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u4f7f\u7528 <code>ROUND<\/code> \u51fd\u6578\u4f86\u56db\u6368\u4e94\u5165\u4e00\u500b\u6578\u5b57\uff1a<\/p>\n<pre><code>SELECT ROUND(123.4567, 2) AS RoundedValue;<\/code><\/pre>\n<h2 id=\"2-%e5%ad%97%e7%ac%a6%e4%b8%b2%e5%87%bd%e6%95%b8-UwqCLoQNgf\">2. \u5b57\u7b26\u4e32\u51fd\u6578<\/h2>\n<p>\u5b57\u7b26\u4e32\u51fd\u6578\u5728\u6578\u64da\u5eab\u4e2d\u7528\u65bc\u8655\u7406\u548c\u64cd\u4f5c\u6587\u672c\u6578\u64da\u3002Sybase \u63d0\u4f9b\u4e86\u591a\u7a2e\u5b57\u7b26\u4e32\u51fd\u6578\uff0c\u5305\u62ec\uff1a<\/p>\n<ul>\n<li><code>LEN(string)<\/code>\uff1a\u8fd4\u56de\u5b57\u7b26\u4e32\u7684\u9577\u5ea6\u3002<\/li>\n<li><code>UPPER(string)<\/code>\uff1a\u5c07\u5b57\u7b26\u4e32\u8f49\u63db\u70ba\u5927\u5beb\u3002<\/li>\n<li><code>LOWER(string)<\/code>\uff1a\u5c07\u5b57\u7b26\u4e32\u8f49\u63db\u70ba\u5c0f\u5beb\u3002<\/li>\n<li><code>SUBSTRING(string, start, length)<\/code>\uff1a\u8fd4\u56de\u5b57\u7b26\u4e32\u7684\u5b50\u4e32\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u4f7f\u7528 <code>SUBSTRING<\/code> \u51fd\u6578\u4f86\u63d0\u53d6\u5b57\u7b26\u4e32\u7684\u4e00\u90e8\u5206\uff1a<\/p>\n<pre><code>SELECT SUBSTRING('Hello, World!', 1, 5) AS SubstringValue;<\/code><\/pre>\n<h2 id=\"3-%e6%97%a5%e6%9c%9f%e5%92%8c%e6%99%82%e9%96%93%e5%87%bd%e6%95%b8-UwqCLoQNgf\">3. \u65e5\u671f\u548c\u6642\u9593\u51fd\u6578<\/h2>\n<p>\u65e5\u671f\u548c\u6642\u9593\u51fd\u6578\u7528\u65bc\u8655\u7406\u65e5\u671f\u548c\u6642\u9593\u6578\u64da\u3002Sybase \u63d0\u4f9b\u7684\u5e38\u7528\u65e5\u671f\u548c\u6642\u9593\u51fd\u6578\u5305\u62ec\uff1a<\/p>\n<ul>\n<li><code>GETDATE()<\/code>\uff1a\u8fd4\u56de\u7576\u524d\u7684\u65e5\u671f\u548c\u6642\u9593\u3002<\/li>\n<li><code>DATEDIFF(datepart, startdate, enddate)<\/code>\uff1a\u8a08\u7b97\u5169\u500b\u65e5\u671f\u4e4b\u9593\u7684\u5dee\u7570\u3002<\/li>\n<li><code>DATEADD(datepart, number, date)<\/code>\uff1a\u5728\u6307\u5b9a\u7684\u65e5\u671f\u4e0a\u6dfb\u52a0\u6307\u5b9a\u7684\u6642\u9593\u9593\u9694\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u4f7f\u7528 <code>DATEDIFF<\/code> \u51fd\u6578\u4f86\u8a08\u7b97\u5169\u500b\u65e5\u671f\u4e4b\u9593\u7684\u5929\u6578\uff1a<\/p>\n<pre><code>SELECT DATEDIFF(DAY, '2023-01-01', '2023-12-31') AS DaysDifference;<\/code><\/pre>\n<h2 id=\"4-%e8%81%9a%e5%90%88%e5%87%bd%e6%95%b8-UwqCLoQNgf\">4. \u805a\u5408\u51fd\u6578<\/h2>\n<p>\u805a\u5408\u51fd\u6578\u7528\u65bc\u5c0d\u4e00\u7d44\u503c\u9032\u884c\u8a08\u7b97\uff0c\u4e26\u8fd4\u56de\u55ae\u4e00\u7684\u503c\u3002Sybase \u7684\u805a\u5408\u51fd\u6578\u5305\u62ec\uff1a<\/p>\n<ul>\n<li><code>SUM(expression)<\/code>\uff1a\u8a08\u7b97\u4e00\u7d44\u503c\u7684\u7e3d\u548c\u3002<\/li>\n<li><code>AVG(expression)<\/code>\uff1a\u8a08\u7b97\u4e00\u7d44\u503c\u7684\u5e73\u5747\u503c\u3002<\/li>\n<li><code>COUNT(expression)<\/code>\uff1a\u8a08\u7b97\u4e00\u7d44\u503c\u7684\u6578\u91cf\u3002<\/li>\n<li><code>MAX(expression)<\/code>\uff1a\u8fd4\u56de\u4e00\u7d44\u503c\u4e2d\u7684\u6700\u5927\u503c\u3002<\/li>\n<li><code>MIN(expression)<\/code>\uff1a\u8fd4\u56de\u4e00\u7d44\u503c\u4e2d\u7684\u6700\u5c0f\u503c\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u4f7f\u7528 <code>SUM<\/code> \u51fd\u6578\u4f86\u8a08\u7b97\u67d0\u500b\u5217\u7684\u7e3d\u548c\uff1a<\/p>\n<pre><code>SELECT SUM(Salary) AS TotalSalary FROM Employees;<\/code><\/pre>\n<h2 id=\"5-%e6%a2%9d%e4%bb%b6%e5%87%bd%e6%95%b8-UwqCLoQNgf\">5. \u689d\u4ef6\u51fd\u6578<\/h2>\n<p>\u689d\u4ef6\u51fd\u6578\u7528\u65bc\u6839\u64da\u7279\u5b9a\u689d\u4ef6\u8fd4\u56de\u4e0d\u540c\u7684\u503c\u3002Sybase \u4e2d\u7684\u5e38\u7528\u689d\u4ef6\u51fd\u6578\u5305\u62ec\uff1a<\/p>\n<ul>\n<li><code>CASE<\/code>\uff1a\u6839\u64da\u689d\u4ef6\u8fd4\u56de\u4e0d\u540c\u7684\u7d50\u679c\u3002<\/li>\n<li><code>COALESCE(expression1, expression2, ...)<\/code>\uff1a\u8fd4\u56de\u7b2c\u4e00\u500b\u975e\u7a7a\u7684\u8868\u9054\u5f0f\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u4f7f\u7528 <code>CASE<\/code> \u51fd\u6578\u4f86\u6839\u64da\u5206\u6578\u8fd4\u56de\u7b49\u7d1a\uff1a<\/p>\n<pre><code>SELECT \n    CASE \n        WHEN Score &gt;= 90 THEN 'A'\n        WHEN Score &gt;= 80 THEN 'B'\n        WHEN Score &gt;= 70 THEN 'C'\n        ELSE 'D'\n    END AS Grade\nFROM Students;<\/code><\/pre>\n<h2 id=\"%e7%b8%bd%e7%b5%90-UwqCLoQNgf\">\u7e3d\u7d50<\/h2>\n<p>Sybase \u6578\u64da\u5eab\u63d0\u4f9b\u4e86\u591a\u7a2e\u5f37\u5927\u7684\u51fd\u6578\uff0c\u5e6b\u52a9\u7528\u6236\u9032\u884c\u6578\u64da\u8655\u7406\u548c\u5206\u6790\u3002\u7121\u8ad6\u662f\u6578\u5b78\u8a08\u7b97\u3001\u5b57\u7b26\u4e32\u64cd\u4f5c\u3001\u65e5\u671f\u8655\u7406\u9084\u662f\u805a\u5408\u8a08\u7b97\uff0c\u9019\u4e9b\u51fd\u6578\u90fd\u80fd\u6709\u6548\u63d0\u5347\u6578\u64da\u8655\u7406\u7684\u6548\u7387\u3002\u4e86\u89e3\u548c\u638c\u63e1\u9019\u4e9b\u51fd\u6578\uff0c\u5c0d\u65bc\u6578\u64da\u5eab\u7ba1\u7406\u548c\u958b\u767c\u4eba\u54e1\u4f86\u8aaa\u90fd\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u60a8\u7684\u9700\u6c42\u3002\u7121\u8ad6\u662f <a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a> \u9084\u662f <a href=\"https:\/\/server.hk\">\u4e91\u4f3a\u670d\u5668<\/a>\uff0c\u6211\u5011\u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u53ef\u9760\u7684\u670d\u52d9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22Sybase\u6578\u64da\u5eab\u7684\u5404\u7a2e\u51fd\u6578\uff0c\u4e86\u89e3\u5176\u529f\u80fd\u3001\u7528\u6cd5\u53ca\u6700\u4f73\u5be6\u8e10\uff0c\u63d0\u5347\u6578\u64da\u7ba1\u7406\u6548\u7387\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-168657","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168657","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=168657"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168657\/revisions"}],"predecessor-version":[{"id":168658,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/168657\/revisions\/168658"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=168657"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=168657"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=168657"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}