{"id":967,"date":"2025-01-15T00:39:16","date_gmt":"2025-01-14T16:39:16","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=967"},"modified":"2025-01-15T00:39:16","modified_gmt":"2025-01-14T16:39:16","slug":"t-sql-%e4%b8%ad%e7%9a%84-set-%e4%b8%8e-select%ef%bc%9a%e4%bd%95%e6%97%b6%e4%bd%bf%e7%94%a8%e5%ae%83%e4%bb%ac%e8%bf%9b%e8%a1%8c%e5%8f%98%e9%87%8f%e8%b5%8b%e5%80%bc%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/01\/15\/t-sql-%e4%b8%ad%e7%9a%84-set-%e4%b8%8e-select%ef%bc%9a%e4%bd%95%e6%97%b6%e4%bd%bf%e7%94%a8%e5%ae%83%e4%bb%ac%e8%bf%9b%e8%a1%8c%e5%8f%98%e9%87%8f%e8%b5%8b%e5%80%bc%ef%bc%9f\/","title":{"rendered":"T-SQL \u4e2d\u7684 SET \u4e0e SELECT\uff1a\u4f55\u65f6\u4f7f\u7528\u5b83\u4eec\u8fdb\u884c\u53d8\u91cf\u8d4b\u503c\uff1f"},"content":{"rendered":"\n
\n

\u5728 T-SQL\uff08SQL Server \u7684\u6269\u5c55\u8bed\u8a00\uff09\u4e2d\uff0cSET<\/code> \u548c SELECT<\/code> \u90fd\u53ef\u4ee5\u7528\u6765\u4e3a\u53d8\u91cf\u8d4b\u503c\uff0c\u4f46\u5b83\u4eec\u7684\u4f7f\u7528\u573a\u666f\u548c\u8bed\u6cd5\u7ec6\u8282\u7565\u6709\u4e0d\u540c\u3002\u7406\u89e3\u8fd9\u4e24\u8005\u7684\u533a\u522b\u548c\u9002\u7528\u65f6\u673a\u5bf9\u4e8e\u7f16\u5199\u6e05\u6670\u3001\u4f18\u5316\u7684 SQL \u67e5\u8be2\u975e\u5e38\u91cd\u8981\u3002\u4e0b\u9762\u5c06\u8be6\u7ec6\u8ba8\u8bba\u4f55\u65f6\u4f7f\u7528 SET<\/code> \u548c SELECT<\/code> \u6765\u8fdb\u884c\u53d8\u91cf\u8d4b\u503c\u3002<\/p>\n<\/blockquote>\n\n\n\n

1. \u57fa\u672c\u8bed\u6cd5\u5bf9\u6bd4<\/strong><\/h3>\n\n\n\n

a. SET \u8d4b\u503c<\/strong><\/h4>\n\n\n\n

SET<\/code> \u662f\u7528\u4e8e\u5355\u4e2a\u53d8\u91cf\u8d4b\u503c\u7684\u6807\u51c6\u65b9\u5f0f\u3002\u5b83\u901a\u5e38\u7528\u4e8e\u4e3a\u4e00\u4e2a\u53d8\u91cf\u8d4b\u4e88\u67d0\u4e2a\u5177\u4f53\u7684\u503c\u3002<\/p>\n\n\n\n

SET @variable = value;<\/code><\/pre>\n\n\n\n
b. SELECT \u8d4b\u503c<\/strong><\/h4>\n\n\n\n
SELECT<\/code> \u4e5f\u53ef\u4ee5\u7528\u6765\u4e3a\u53d8\u91cf\u8d4b\u503c\uff0c\u901a\u5e38\u7528\u4e8e\u591a\u4e2a\u53d8\u91cf\u6216\u4ece\u67e5\u8be2\u7ed3\u679c\u4e2d\u4e3a\u53d8\u91cf\u8d4b\u503c\u3002<\/p>\n\n\n\n
SELECT @variable = value;<\/code><\/pre>\n\n\n\n
2. \u4e3b\u8981\u533a\u522b<\/strong><\/h3>\n\n\n\n
a. \u8d4b\u503c\u884c\u4e3a<\/strong><\/h4>\n\n\n\n
    \n
  • SET<\/code> \u8d4b\u503c\u53ea\u652f\u6301\u5355\u4e00\u53d8\u91cf\u8d4b\u503c<\/strong>\u3002\u5982\u679c\u5c1d\u8bd5\u5c06\u591a\u4e2a\u5217\u6216\u591a\u884c\u6570\u636e\u8d4b\u503c\u7ed9\u53d8\u91cf\uff0cSET<\/code> \u4f1a\u629b\u51fa\u9519\u8bef\u3002<\/li>\n\n\n\n
  • SELECT<\/code> \u8d4b\u503c\u53ef\u4ee5\u540c\u65f6\u4e3a\u591a\u4e2a\u53d8\u91cf\u8d4b\u503c\uff0c\u5e76\u4e14\u53ef\u4ee5\u4ece\u67e5\u8be2\u7684\u7ed3\u679c\u4e2d\u4e3a\u53d8\u91cf\u8d4b\u503c\u3002<\/li>\n<\/ul>\n\n\n\n
    b. \u6027\u80fd<\/strong><\/h4>\n\n\n\n
    \u5728\u4e00\u4e9b\u590d\u6742\u7684\u67e5\u8be2\u4e2d\uff0cSET<\/code> \u4e0e SELECT<\/code> \u7684\u6027\u80fd\u5dee\u5f02\u53ef\u80fd\u4f1a\u5f71\u54cd\u67e5\u8be2\u7684\u6548\u7387\u3002\u4e00\u822c\u6765\u8bf4\uff0cSET<\/code> \u88ab\u8ba4\u4e3a\u5728\u5904\u7406\u5355\u4e2a\u503c\u65f6\u66f4\u4e3a\u9ad8\u6548\uff0c\u7279\u522b\u662f\u5728\u8d4b\u503c\u64cd\u4f5c\u8f83\u4e3a\u7b80\u5355\u65f6\uff0cSELECT<\/code> \u53ef\u80fd\u4f1a\u7a0d\u5fae\u6709\u4e9b\u5f00\u9500\u3002<\/p>\n\n\n\n
    c. \u591a\u884c\u7ed3\u679c\u8d4b\u503c<\/strong><\/h4>\n\n\n\n
      \n
    • \u5982\u679c\u67e5\u8be2\u8fd4\u56de\u591a\u884c\u7ed3\u679c\u65f6\uff0c\u4f7f\u7528 SET<\/code> \u4f1a\u5bfc\u81f4\u9519\u8bef\uff0c\u56e0\u5b83\u53ea\u5141\u8bb8\u8d4b\u503c\u7ed9\u5355\u4e2a\u503c\uff08\u4f8b\u5982\uff0c\u4e00\u884c\u6570\u636e\uff09\u3002<\/li>\n\n\n\n
    • SELECT<\/code> \u5141\u8bb8\u901a\u8fc7\u8d4b\u503c\u7ed9\u53d8\u91cf\u6355\u83b7\u591a\u884c\u6570\u636e\uff0c\u4e14\u4f1a\u81ea\u52a8\u8fd4\u56de\u6700\u540e\u4e00\u884c\u7684\u503c\u3002<\/li>\n<\/ul>\n\n\n\n
      d. \u9519\u8bef\u5904\u7406\u4e0e\u63a7\u5236\u6d41<\/strong><\/h4>\n\n\n\n
      SET<\/code> \u662f\u6807\u51c6\u7684\u8d4b\u503c\u8bed\u53e5\uff0c\u56e0\u6b64\u5f53\u9047\u5230\u95ee\u9898\u65f6\uff0cSQL Server \u53ef\u4ee5\u63d0\u4f9b\u66f4\u660e\u786e\u7684\u9519\u8bef\u4fe1\u606f\u3002\u800c\u4f7f\u7528 SELECT<\/code> \u8d4b\u503c\u65f6\uff0c\u5982\u679c\u67e5\u8be2\u8fd4\u56de\u591a\u4e2a\u503c\uff0c\u4f1a\u4ea7\u751f\u672a\u5b9a\u4e49\u7684\u884c\u4e3a\uff0c\u8fd9\u53ef\u80fd\u5bfc\u81f4\u7a0b\u5e8f\u5f02\u5e38\u6216\u610f\u5916\u7ed3\u679c\u3002<\/p>\n\n\n\n
      3. \u4f55\u65f6\u4f7f\u7528 SET<\/code><\/strong><\/h3>\n\n\n\n
      SET<\/code> \u662f\u7528\u6765\u8d4b\u503c\u5355\u4e2a\u53d8\u91cf<\/strong>\u7684\u6807\u51c6\u8bed\u53e5\u3002\u5f53\u4f60\u60f3\u8981\u786e\u4fdd\u5355\u4e00\u53d8\u91cf\u5f97\u5230\u51c6\u786e\u7684\u8d4b\u503c\u65f6\uff0c\u5e94\u8be5\u4f7f\u7528 SET<\/code>\u3002<\/p>\n\n\n\n
        \n
      • \u5355\u4e00\u8d4b\u503c\uff1a<\/strong><\/li>\n<\/ul>\n\n\n\n
          DECLARE @name NVARCHAR(50);\n  SET @name = 'John Doe';<\/code><\/pre>\n\n\n\n
          \n
        • \u907f\u514d\u591a\u884c\u8d4b\u503c\uff1a<\/strong>
          \u5f53\u4f60\u4e0d\u786e\u5b9a\u67e5\u8be2\u7ed3\u679c\u662f\u5426\u53ef\u80fd\u8fd4\u56de\u591a\u4e2a\u884c\u65f6\uff0c\u6700\u597d\u4f7f\u7528 SET<\/code>\u3002\u5982\u679c\u67e5\u8be2\u8fd4\u56de\u591a\u884c\u6570\u636e\uff0cSET<\/code> \u4f1a\u629b\u51fa\u9519\u8bef\u3002<\/li>\n\n\n\n
        • \u660e\u786e\u8868\u8fbe\u8d4b\u503c\u610f\u56fe\uff1a<\/strong>
          \u4f7f\u7528 SET<\/code> \u4f7f\u5f97\u4f60\u7684\u610f\u56fe\u66f4\u52a0\u6e05\u6670\uff1a\u4f60\u53ea\u60f3\u8d4b\u503c\u4e00\u4e2a\u53d8\u91cf\u3002<\/li>\n<\/ul>\n\n\n\n
          4. \u4f55\u65f6\u4f7f\u7528 SELECT<\/code><\/strong><\/h3>\n\n\n\n
          SELECT<\/code> \u66f4\u9002\u7528\u4e8e\u8d4b\u503c\u591a\u4e2a\u53d8\u91cf<\/strong>\u6216\u4ece\u67e5\u8be2\u7ed3\u679c\u4e2d\u63d0\u53d6\u503c\u8d4b\u7ed9\u53d8\u91cf\u7684\u60c5\u51b5\u3002\u5b83\u5728\u540c\u65f6\u4e3a\u591a\u4e2a\u53d8\u91cf\u8d4b\u503c\u65f6\u5c24\u5176\u6709\u7528\u3002<\/p>\n\n\n\n
            \n
          • \u591a\u4e2a\u53d8\u91cf\u8d4b\u503c\uff1a<\/strong><\/li>\n<\/ul>\n\n\n\n
              DECLARE @first_name NVARCHAR(50), @last_name NVARCHAR(50);\n  SELECT @first_name = first_name, @last_name = last_name\n  FROM employees\n  WHERE employee_id = 1;<\/code><\/pre>\n\n\n\n
              \n
            • \u4ece\u67e5\u8be2\u7ed3\u679c\u4e2d\u63d0\u53d6\u591a\u4e2a\u503c\uff1a<\/strong>
              \u5f53\u4f60\u60f3\u4ece\u4e00\u4e2a\u67e5\u8be2\u7ed3\u679c\u4e2d\u63d0\u53d6\u591a\u4e2a\u503c\u5e76\u8d4b\u7ed9\u4e0d\u540c\u7684\u53d8\u91cf\u65f6\uff0cSELECT<\/code> \u975e\u5e38\u65b9\u4fbf\u3002<\/li>\n\n\n\n
            • \u4ece\u67e5\u8be2\u8fd4\u56de\u6700\u540e\u4e00\u884c\u7684\u503c\uff1a<\/strong>
              \u5982\u679c\u67e5\u8be2\u8fd4\u56de\u591a\u4e2a\u503c\uff0cSELECT<\/code> \u4f1a\u4f7f\u7528\u6700\u540e\u4e00\u884c\u7684\u7ed3\u679c<\/strong>\u8d4b\u503c\u7ed9\u53d8\u91cf\u3002\u4e3e\u4e2a\u4f8b\u5b50\uff1a<\/li>\n<\/ul>\n\n\n\n
                DECLARE @last_name NVARCHAR(50);\n  SELECT @last_name = last_name\n  FROM employees\n  WHERE department = 'HR';<\/code><\/pre>\n\n\n\n
              \u8fd9\u91cc\u5373\u4f7f\u6709\u591a\u4e2a\u7b26\u5408\u6761\u4ef6\u7684\u884c\uff0c@last_name<\/code> \u4e5f\u53ea\u4f1a\u5f97\u5230\u6700\u540e\u4e00\u884c<\/strong>\u7684 last_name<\/code>\u3002<\/p>\n\n\n\n
              5. \u4f7f\u7528\u573a\u666f\u6bd4\u8f83<\/strong><\/h3>\n\n\n\n
              \u7279\u6027<\/th>SET<\/code> \u7528\u6cd5<\/th>SELECT<\/code> \u7528\u6cd5<\/th><\/tr><\/thead>
              \u8d4b\u503c\u5355\u4e00\u53d8\u91cf<\/strong><\/td>\u63a8\u8350\u4f7f\u7528 SET<\/code>\uff0c\u8bed\u6cd5\u7b80\u6d01\u4e14\u6e05\u6670<\/td>\u4e5f\u53ef\u4ee5\u4f7f\u7528 SELECT<\/code>\uff0c\u4f46\u4e0d\u63a8\u8350<\/td><\/tr>
              \u591a\u4e2a\u53d8\u91cf\u8d4b\u503c<\/strong><\/td>\u4e0d\u652f\u6301<\/td>\u652f\u6301\u540c\u65f6\u4e3a\u591a\u4e2a\u53d8\u91cf\u8d4b\u503c<\/td><\/tr>
              \u591a\u884c\u67e5\u8be2\u7ed3\u679c<\/strong><\/td>\u4f1a\u629b\u51fa\u9519\u8bef\uff0c\u4e0d\u80fd\u8d4b\u503c\u591a\u4e2a\u884c\u7684\u7ed3\u679c<\/td>\u4f7f\u7528\u65f6\u4f1a\u8d4b\u503c\u6700\u540e\u4e00\u884c\u7684\u7ed3\u679c<\/td><\/tr>
              \u6027\u80fd<\/strong><\/td>\u66f4\u9002\u5408\u7b80\u5355\u7684\u5355\u4e00\u8d4b\u503c<\/td>\u5728\u590d\u6742\u67e5\u8be2\u65f6\u53ef\u80fd\u4f1a\u7565\u6709\u6027\u80fd\u5f00\u9500<\/td><\/tr>
              \u9519\u8bef\u5904\u7406<\/strong><\/td>\u9519\u8bef\u66f4\u5177\u660e\u786e\u6027<\/td>\u5982\u679c\u8fd4\u56de\u591a\u4e2a\u7ed3\u679c\uff0c\u884c\u4e3a\u4e0d\u660e\u786e<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
              6. \u603b\u7ed3<\/strong><\/h3>\n\n\n\n
                \n
              • \u4f7f\u7528 SET<\/code><\/strong>\uff1a\u5f53\u4f60\u9700\u8981\u4e3a\u5355\u4e2a\u53d8\u91cf\u8d4b\u503c\u65f6\uff0cSET<\/code> \u66f4\u4e3a\u6807\u51c6\u4e14\u5177\u6709\u660e\u786e\u7684\u884c\u4e3a\uff0c\u907f\u514d\u4e86\u591a\u884c\u7ed3\u679c\u8d4b\u503c\u7684\u6f5c\u5728\u95ee\u9898\u3002<\/li>\n\n\n\n
              • \u4f7f\u7528 SELECT<\/code><\/strong>\uff1a\u5f53\u4f60\u9700\u8981\u4e3a\u591a\u4e2a\u53d8\u91cf\u8d4b\u503c\uff0c\u6216\u8005\u4ece\u67e5\u8be2\u7ed3\u679c\u4e2d\u63d0\u53d6\u503c\u8d4b\u7ed9\u53d8\u91cf\u65f6\uff0cSELECT<\/code> \u662f\u66f4\u597d\u7684\u9009\u62e9\u3002\u4f46\u8981\u6ce8\u610f\u5b83\u8d4b\u503c\u7ed9\u53d8\u91cf\u65f6\u4f1a\u4ec5\u8fd4\u56de\u67e5\u8be2\u7ed3\u679c\u7684\u6700\u540e\u4e00\u884c\u3002<\/li>\n<\/ul>\n\n\n\n
                \u5728\u7f16\u5199 SQL \u65f6\uff0c\u5408\u7406\u4f7f\u7528\u8fd9\u4e24\u79cd\u8d4b\u503c\u65b9\u5f0f\uff0c\u80fd\u591f\u63d0\u5347\u4ee3\u7801\u7684\u53ef\u8bfb\u6027\u548c\u7a33\u5b9a\u6027\uff0c\u540c\u65f6\u907f\u514d\u6f5c\u5728\u7684\u9519\u8bef\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
                \u5728 T-SQL\uff08SQL Server \u7684\u6269\u5c55\u8bed\u8a00\uff09\u4e2d\uff0cSET \u548c SELECT \u90fd\u53ef\u4ee5\u7528\u6765\u4e3a\u53d8\u91cf\u8d4b\u503c\uff0c\u4f46\u5b83\u4eec\u7684 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35],"tags":[],"class_list":["post-967","post","type-post","status-publish","format-standard","hentry","category-mysql"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/967","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/comments?post=967"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/967\/revisions"}],"predecessor-version":[{"id":968,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/967\/revisions\/968"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=967"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=967"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=967"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}