{"id":1573,"date":"2025-02-12T22:17:59","date_gmt":"2025-02-12T14:17:59","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=1573"},"modified":"2025-02-12T22:18:01","modified_gmt":"2025-02-12T14:18:01","slug":"%e5%9f%ba%e7%a1%80-sql-%e8%af%ad%e6%b3%95%e4%b8%8e%e6%93%8d%e4%bd%9c%ef%bc%9aoracle-sql-%e5%85%a5%e9%97%a8%e6%95%99%e7%a8%8b","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/02\/12\/%e5%9f%ba%e7%a1%80-sql-%e8%af%ad%e6%b3%95%e4%b8%8e%e6%93%8d%e4%bd%9c%ef%bc%9aoracle-sql-%e5%85%a5%e9%97%a8%e6%95%99%e7%a8%8b\/","title":{"rendered":"\u57fa\u7840 SQL \u8bed\u6cd5\u4e0e\u64cd\u4f5c\uff1aOracle SQL \u5165\u95e8\u6559\u7a0b"},"content":{"rendered":"\n

1. SQL \u57fa\u7840<\/strong><\/h4>\n\n\n\n

SQL\uff08\u7ed3\u6784\u5316\u67e5\u8be2\u8bed\u8a00\uff09\u662f\u7528\u4e8e\u4e0e\u6570\u636e\u5e93\u4ea4\u4e92\u7684\u6807\u51c6\u8bed\u8a00\u3002\u5728 Oracle \u6570\u636e\u5e93\u4e2d\uff0cSQL \u7528\u6765\u5b9a\u4e49\u6570\u636e\u5e93\u7ed3\u6784\u3001\u64cd\u63a7\u6570\u636e\u4ee5\u53ca\u67e5\u8be2\u6570\u636e\u3002SQL \u7684\u57fa\u672c\u529f\u80fd\u5305\u62ec\u6570\u636e\u67e5\u8be2\u3001\u6570\u636e\u66f4\u65b0\u3001\u6570\u636e\u63d2\u5165\u548c\u6570\u636e\u5220\u9664\u3002<\/p>\n\n\n\n

\n\n\n\n

2. SELECT \u67e5\u8be2\u8bed\u53e5<\/strong><\/h4>\n\n\n\n

SELECT<\/code> \u662f SQL \u4e2d\u6700\u5e38\u7528\u7684\u547d\u4ee4\uff0c\u7528\u6765\u4ece\u6570\u636e\u5e93\u4e2d\u68c0\u7d22\u6570\u636e\u3002<\/p>\n\n\n\n

\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n

SELECT first_name, last_name, email FROM employees;<\/code><\/pre>\n\n\n\n
    \n
  • \u8be5\u67e5\u8be2\u4ece employees<\/code> \u8868\u4e2d\u83b7\u53d6 first_name<\/code>\u3001last_name<\/code> \u548c email<\/code> \u5b57\u6bb5\u7684\u6570\u636e\u3002<\/li>\n<\/ul>\n\n\n\n
    \u4f7f\u7528 DISTINCT \u53bb\u91cd\uff1a<\/strong><\/p>\n\n\n\n
    SELECT DISTINCT department_id FROM employees;<\/code><\/pre>\n\n\n\n
      \n
    • \u83b7\u53d6\u4e0d\u540c\u7684\u90e8\u95e8 ID\u3002<\/li>\n<\/ul>\n\n\n\n
      \n\n\n\n
      3. WHERE \u5b50\u53e5\u4e0e\u903b\u8f91\u8fd0\u7b97\u7b26<\/strong><\/h4>\n\n\n\n
      WHERE<\/code> \u5b50\u53e5\u7528\u4e8e\u6307\u5b9a\u67e5\u8be2\u6761\u4ef6\uff0c\u5e38\u4e0e\u903b\u8f91\u8fd0\u7b97\u7b26\u7ed3\u5408\u4f7f\u7528\u3002<\/p>\n\n\n\n
      \u5e38\u7528\u7684\u903b\u8f91\u8fd0\u7b97\u7b26\uff1a<\/strong><\/p>\n\n\n\n
        \n
      • AND<\/code>\uff1a\u4e24\u4e2a\u6761\u4ef6\u90fd\u5fc5\u987b\u4e3a\u771f<\/li>\n\n\n\n
      • OR<\/code>\uff1a\u81f3\u5c11\u6709\u4e00\u4e2a\u6761\u4ef6\u4e3a\u771f<\/li>\n\n\n\n
      • NOT<\/code>\uff1a\u6761\u4ef6\u4e0d\u6210\u7acb\u65f6\u4e3a\u771f<\/li>\n<\/ul>\n\n\n\n
        \u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n
        SELECT first_name, last_name\nFROM employees\nWHERE department_id = 10 AND salary > 5000;<\/code><\/pre>\n\n\n\n
          \n
        • \u67e5\u8be2\u90e8\u95e8 ID \u4e3a 10 \u4e14\u5de5\u8d44\u5927\u4e8e 5000 \u7684\u5458\u5de5\u3002<\/li>\n<\/ul>\n\n\n\n
          \n\n\n\n
          4. \u5e38\u7528\u7684 SQL \u805a\u5408\u51fd\u6570<\/strong><\/h4>\n\n\n\n
          SQL \u63d0\u4f9b\u4e86\u591a\u79cd\u805a\u5408\u51fd\u6570\uff0c\u7528\u4e8e\u8ba1\u7b97\u6570\u636e\u96c6\u7684\u603b\u548c\u3001\u5e73\u5747\u503c\u7b49\u3002<\/p>\n\n\n\n
            \n
          • COUNT<\/strong>\uff1a\u8fd4\u56de\u7ed3\u679c\u96c6\u4e2d\u7684\u884c\u6570<\/li>\n\n\n\n
          • SUM<\/strong>\uff1a\u8fd4\u56de\u67d0\u5217\u6570\u503c\u7684\u603b\u548c<\/li>\n\n\n\n
          • AVG<\/strong>\uff1a\u8fd4\u56de\u67d0\u5217\u6570\u503c\u7684\u5e73\u5747\u503c<\/li>\n\n\n\n
          • MIN<\/strong>\uff1a\u8fd4\u56de\u67d0\u5217\u7684\u6700\u5c0f\u503c<\/li>\n\n\n\n
          • MAX<\/strong>\uff1a\u8fd4\u56de\u67d0\u5217\u7684\u6700\u5927\u503c<\/li>\n<\/ul>\n\n\n\n
            \u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n
            SELECT COUNT(*), AVG(salary), MAX(salary), MIN(salary)\nFROM employees;<\/code><\/pre>\n\n\n\n
              \n
            • \u8ba1\u7b97\u5458\u5de5\u603b\u6570\u3001\u5e73\u5747\u5de5\u8d44\u3001\u6700\u9ad8\u5de5\u8d44\u548c\u6700\u4f4e\u5de5\u8d44\u3002<\/li>\n<\/ul>\n\n\n\n
              \n\n\n\n
              5. \u6570\u636e\u64cd\u63a7<\/strong><\/h4>\n\n\n\n
                \n
              • INSERT \u8bed\u53e5<\/strong>\uff1a\u5411\u8868\u4e2d\u63d2\u5165\u6570\u636e<\/li>\n<\/ul>\n\n\n\n
                  INSERT INTO employees (first_name, last_name, email, hire_date, salary)\n  VALUES ('John', 'Doe', 'john.doe@example.com', SYSDATE, 6000);<\/code><\/pre>\n\n\n\n
                  \n
                • UPDATE \u8bed\u53e5<\/strong>\uff1a\u66f4\u65b0\u8868\u4e2d\u7684\u6570\u636e<\/li>\n<\/ul>\n\n\n\n
                    UPDATE employees\n  SET salary = 7000\n  WHERE employee_id = 101;<\/code><\/pre>\n\n\n\n
                    \n
                  • DELETE \u8bed\u53e5<\/strong>\uff1a\u5220\u9664\u8868\u4e2d\u7684\u6570\u636e<\/li>\n<\/ul>\n\n\n\n
                      DELETE FROM employees\n  WHERE employee_id = 101;<\/code><\/pre>\n\n\n\n
                    \n\n\n\n
                    6. \u6570\u636e\u9a8c\u8bc1\u4e0e\u7ea6\u675f<\/strong><\/h4>\n\n\n\n
                    \u5728\u6570\u636e\u5e93\u8bbe\u8ba1\u4e2d\uff0c\u7ea6\u675f\u7528\u4e8e\u786e\u4fdd\u6570\u636e\u7684\u5b8c\u6574\u6027\u3002<\/p>\n\n\n\n
                      \n
                    • PRIMARY KEY<\/strong>\uff1a\u4e3b\u952e\u7ea6\u675f\uff0c\u7528\u4e8e\u552f\u4e00\u6807\u8bc6\u8868\u4e2d\u7684\u6bcf\u4e00\u884c\u3002<\/li>\n\n\n\n
                    • FOREIGN KEY<\/strong>\uff1a\u5916\u952e\u7ea6\u675f\uff0c\u7528\u4e8e\u786e\u4fdd\u6570\u636e\u4e4b\u95f4\u7684\u5173\u7cfb\u3002<\/li>\n\n\n\n
                    • UNIQUE<\/strong>\uff1a\u786e\u4fdd\u5217\u4e2d\u7684\u6bcf\u4e2a\u503c\u90fd\u662f\u552f\u4e00\u7684\u3002<\/li>\n\n\n\n
                    • CHECK<\/strong>\uff1a\u786e\u4fdd\u5217\u7684\u503c\u6ee1\u8db3\u7279\u5b9a\u6761\u4ef6\u3002<\/li>\n<\/ul>\n\n\n\n
                      \u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n
                      CREATE TABLE employees (\n    employee_id INT PRIMARY KEY,\n    first_name VARCHAR(50),\n    last_name VARCHAR(50),\n    salary DECIMAL(10, 2) CHECK (salary > 0)\n);<\/code><\/pre>\n\n\n\n
                        \n
                      • \u5728 employees<\/code> \u8868\u4e2d\uff0cemployee_id<\/code> \u4e3a\u4e3b\u952e\uff0csalary<\/code> \u5217\u786e\u4fdd\u5927\u4e8e\u96f6\u3002<\/li>\n<\/ul>\n\n\n\n
                        \n\n\n\n
                        7. \u6570\u636e\u5b9a\u4e49\u4e0e\u7ba1\u7406<\/strong><\/h4>\n\n\n\n
                          \n
                        • \u521b\u5efa\u8868<\/strong>\uff1a<\/li>\n<\/ul>\n\n\n\n
                            CREATE TABLE employees (\n      employee_id INT PRIMARY KEY,\n      first_name VARCHAR(50),\n      last_name VARCHAR(50),\n      hire_date DATE\n  );<\/code><\/pre>\n\n\n\n
                            \n
                          • \u4fee\u6539\u8868<\/strong>\uff1a\u4f7f\u7528 ALTER TABLE<\/code> \u6dfb\u52a0\u6216\u4fee\u6539\u5217<\/li>\n<\/ul>\n\n\n\n
                              ALTER TABLE employees ADD department_id INT;<\/code><\/pre>\n\n\n\n
                              \n
                            • \u5220\u9664\u8868<\/strong>\uff1a<\/li>\n<\/ul>\n\n\n\n
                                DROP TABLE employees;<\/code><\/pre>\n\n\n\n
                                \n
                              • \u521b\u5efa\u89c6\u56fe<\/strong>\uff1a<\/li>\n<\/ul>\n\n\n\n
                                  CREATE VIEW emp_view AS\n  SELECT first_name, last_name, department_id\n  FROM employees\n  WHERE salary > 5000;<\/code><\/pre>\n\n\n\n
                                \n\n\n\n
                                8. \u7d22\u5f15\u4e0e\u7ea6\u675f<\/strong><\/h4>\n\n\n\n
                                  \n
                                • \u7d22\u5f15<\/strong>\uff1a\u52a0\u901f\u6570\u636e\u68c0\u7d22\u7684\u7ed3\u6784<\/li>\n<\/ul>\n\n\n\n
                                    CREATE INDEX idx_employee_name ON employees (first_name, last_name);<\/code><\/pre>\n\n\n\n
                                    \n
                                  • \u7ea6\u675f<\/strong>\uff1a\u786e\u4fdd\u6570\u636e\u7684\u5b8c\u6574\u6027\uff08\u5982\u4e0a\u8ff0 PRIMARY KEY\u3001FOREIGN KEY\uff09\u3002<\/li>\n<\/ul>\n\n\n\n
                                    \n\n\n\n
                                    9. \u8fde\u63a5\u4e0e\u5b50\u67e5\u8be2<\/strong><\/h4>\n\n\n\n
                                      \n
                                    • \u5185\u8fde\u63a5\uff08INNER JOIN\uff09<\/strong>\uff1a\u8fd4\u56de\u4e24\u4e2a\u8868\u4e2d\u6ee1\u8db3\u8fde\u63a5\u6761\u4ef6\u7684\u8bb0\u5f55<\/li>\n<\/ul>\n\n\n\n
                                        SELECT e.first_name, e.last_name, d.department_name\n  FROM employees e\n  INNER JOIN departments d\n  ON e.department_id = d.department_id;<\/code><\/pre>\n\n\n\n
                                        \n
                                      • \u5916\u8fde\u63a5\uff08LEFT JOIN, RIGHT JOIN\uff09<\/strong>\uff1a\u8fd4\u56de\u4e00\u4e2a\u8868\u7684\u6240\u6709\u8bb0\u5f55\uff0c\u4ee5\u53ca\u53e6\u4e00\u4e2a\u8868\u4e2d\u5339\u914d\u7684\u8bb0\u5f55\u3002\u5982\u679c\u6ca1\u6709\u5339\u914d\uff0c\u53e6\u4e00\u4e2a\u8868\u7684\u5217\u8fd4\u56de NULL\u3002<\/li>\n<\/ul>\n\n\n\n
                                          SELECT e.first_name, d.department_name\n  FROM employees e\n  LEFT JOIN departments d\n  ON e.department_id = d.department_id;<\/code><\/pre>\n\n\n\n
                                          \n
                                        • \u81ea\u8fde\u63a5\uff08Self JOIN\uff09<\/strong>\uff1a\u8fde\u63a5\u540c\u4e00\u4e2a\u8868\uff0c\u7528\u522b\u540d\u533a\u5206\u4e0d\u540c\u7684\u5b9e\u4f8b\u3002<\/li>\n<\/ul>\n\n\n\n
                                            SELECT e1.first_name AS Employee, e2.first_name AS Manager\n  FROM employees e1\n  LEFT JOIN employees e2\n  ON e1.manager_id = e2.employee_id;<\/code><\/pre>\n\n\n\n
                                            \n
                                          • \u4ea4\u53c9\u8fde\u63a5\uff08CROSS JOIN\uff09<\/strong>\uff1a\u8fd4\u56de\u4e24\u4e2a\u8868\u7684\u7b1b\u5361\u5c14\u79ef\uff0c\u901a\u5e38\u7528\u4e8e\u751f\u6210\u6240\u6709\u53ef\u80fd\u7684\u7ec4\u5408\u3002<\/li>\n<\/ul>\n\n\n\n
                                              SELECT e.first_name, p.product_name\n  FROM employees e\n  CROSS JOIN products p;<\/code><\/pre>\n\n\n\n
                                            \n\n\n\n
                                            10. \u5b50\u67e5\u8be2\u4e0e\u5173\u8054\u5b50\u67e5\u8be2<\/strong><\/h4>\n\n\n\n
                                              \n
                                            • \u5b50\u67e5\u8be2<\/strong>\uff1a\u67e5\u8be2\u4e2d\u5d4c\u5957\u7684\u67e5\u8be2\uff0c\u8fd4\u56de\u5355\u4e00\u7ed3\u679c<\/li>\n<\/ul>\n\n\n\n
                                                SELECT first_name, last_name\n  FROM employees\n  WHERE department_id = (SELECT department_id FROM departments WHERE department_name = 'Sales');<\/code><\/pre>\n\n\n\n
                                                \n
                                              • \u5173\u8054\u5b50\u67e5\u8be2<\/strong>\uff1a\u5b50\u67e5\u8be2\u4e0e\u5916\u90e8\u67e5\u8be2\u76f8\u5173\u8054<\/li>\n<\/ul>\n\n\n\n
                                                  SELECT first_name, last_name, salary\n  FROM employees e\n  WHERE salary > (SELECT AVG(salary) FROM employees WHERE department_id = e.department_id);<\/code><\/pre>\n\n\n\n
                                                \n\n\n\n
                                                \u8fd9\u4e9b\u57fa\u672c\u7684 SQL \u8bed\u6cd5\u548c\u64cd\u4f5c\u4e3a\u4f60\u63d0\u4f9b\u4e86 Oracle \u6570\u636e\u5e93\u7684\u57fa\u7840\uff0c\u540e\u7eed\u7684\u5b66\u4e60\u4e2d\u53ef\u4ee5\u6839\u636e\u9700\u8981\u8fdb\u4e00\u6b65\u6df1\u5165\u63a2\u8ba8\u67e5\u8be2\u4f18\u5316\u3001\u6027\u80fd\u8c03\u4f18\u7b49\u5185\u5bb9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
                                                1. SQL \u57fa\u7840 SQL\uff08\u7ed3\u6784\u5316\u67e5\u8be2\u8bed\u8a00\uff09\u662f\u7528\u4e8e\u4e0e\u6570\u636e\u5e93\u4ea4\u4e92\u7684\u6807\u51c6\u8bed\u8a00\u3002\u5728 Oracle \u6570\u636e\u5e93\u4e2d\uff0cSQL  […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[69],"tags":[],"class_list":["post-1573","post","type-post","status-publish","format-standard","hentry","category-oracle"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/1573","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=1573"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/1573\/revisions"}],"predecessor-version":[{"id":1574,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/1573\/revisions\/1574"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=1573"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=1573"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=1573"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}