{"id":1768,"date":"2025-02-18T00:20:14","date_gmt":"2025-02-17T16:20:14","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=1768"},"modified":"2025-02-18T00:20:14","modified_gmt":"2025-02-17T16:20:14","slug":"mysql-where-%e5%ad%90%e5%8f%a5%ef%bc%88%e9%99%84%e5%b8%a6%e5%ae%9e%e4%be%8b%ef%bc%89","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/02\/18\/mysql-where-%e5%ad%90%e5%8f%a5%ef%bc%88%e9%99%84%e5%b8%a6%e5%ae%9e%e4%be%8b%ef%bc%89\/","title":{"rendered":"MySQL WHERE \u5b50\u53e5\uff08\u9644\u5e26\u5b9e\u4f8b\uff09"},"content":{"rendered":"\n

\u5728 MySQL \u4e2d\uff0cWHERE<\/code> \u5b50\u53e5\u7528\u4e8e\u8fc7\u6ee4\u67e5\u8be2\u7ed3\u679c\uff0c\u53ea\u8fd4\u56de\u6ee1\u8db3\u7279\u5b9a\u6761\u4ef6\u7684\u8bb0\u5f55\u3002\u5b83\u901a\u5e38\u4e0e SELECT<\/code>\u3001UPDATE<\/code>\u3001DELETE<\/code> \u7b49\u8bed\u53e5\u4e00\u8d77\u4f7f\u7528\u3002<\/p>\n\n\n\n

1. \u57fa\u672c\u7684 WHERE<\/code> \u5b50\u53e5<\/strong><\/h3>\n\n\n\n

\u57fa\u672c\u8bed\u6cd5<\/strong><\/h4>\n\n\n\n
SELECT column1, column2, ...\nFROM table_name\nWHERE condition;<\/code><\/pre>\n\n\n\n
    \n
  • condition<\/code>\uff1a\u8fc7\u6ee4\u8bb0\u5f55\u7684\u6761\u4ef6\u3002<\/li>\n<\/ul>\n\n\n\n
    \u5b9e\u4f8b\uff1a\u67e5\u8be2\u7279\u5b9a\u6761\u4ef6\u7684\u8bb0\u5f55<\/strong><\/h4>\n\n\n\n
    \u5047\u8bbe\u6709\u4e00\u4e2a users<\/code> \u8868\uff0c\u5305\u542b user_id<\/code>, username<\/code>, email<\/code>, \u548c age<\/code> \u5217\u3002\u4ee5\u4e0b\u662f\u4e00\u4e2a\u67e5\u8be2\u6ee1\u8db3\u6761\u4ef6\u7684\u8bb0\u5f55\u7684\u4f8b\u5b50\uff1a<\/p>\n\n\n\n
    SELECT username, email\nFROM users\nWHERE user_id = 1;<\/code><\/pre>\n\n\n\n
      \n
    • \u8fd9\u4e2a\u67e5\u8be2\u5c06\u8fd4\u56de user_id<\/code> \u4e3a 1 \u7684\u7528\u6237\u7684 username<\/code> \u548c email<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n
      \n\n\n\n
      2. \u4f7f\u7528 AND<\/code> \u8fde\u63a5\u591a\u4e2a\u6761\u4ef6<\/strong><\/h3>\n\n\n\n
      AND<\/code> \u5141\u8bb8\u4f60\u5728 WHERE<\/code> \u5b50\u53e5\u4e2d\u4f7f\u7528\u591a\u4e2a\u6761\u4ef6\uff0c\u53ea\u6709\u5f53\u6240\u6709\u6761\u4ef6\u90fd\u6ee1\u8db3\u65f6\uff0c\u8bb0\u5f55\u624d\u4f1a\u88ab\u8fd4\u56de\u3002<\/p>\n\n\n\n
      \u57fa\u672c\u8bed\u6cd5<\/strong><\/h4>\n\n\n\n
      SELECT column1, column2, ...\nFROM table_name\nWHERE condition1 AND condition2;<\/code><\/pre>\n\n\n\n
      \u5b9e\u4f8b\uff1a\u67e5\u8be2\u7b26\u5408\u591a\u4e2a\u6761\u4ef6\u7684\u8bb0\u5f55<\/strong><\/h4>\n\n\n\n
      SELECT username, email\nFROM users\nWHERE user_id = 1 AND age > 25;<\/code><\/pre>\n\n\n\n
        \n
      • \u8fd9\u4e2a\u67e5\u8be2\u8fd4\u56de user_id<\/code> \u4e3a 1 \u4e14 age<\/code> \u5927\u4e8e 25 \u7684\u7528\u6237\u7684 username<\/code> \u548c email<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n
        \n\n\n\n
        3. \u4f7f\u7528 OR<\/code> \u8fde\u63a5\u591a\u4e2a\u6761\u4ef6<\/strong><\/h3>\n\n\n\n
        OR<\/code> \u5141\u8bb8\u4f60\u5728 WHERE<\/code> \u5b50\u53e5\u4e2d\u4f7f\u7528\u591a\u4e2a\u6761\u4ef6\uff0c\u53ea\u8981\u5176\u4e2d\u4e00\u4e2a\u6761\u4ef6\u6ee1\u8db3\uff0c\u8bb0\u5f55\u5c31\u4f1a\u88ab\u8fd4\u56de\u3002<\/p>\n\n\n\n
        \u57fa\u672c\u8bed\u6cd5<\/strong><\/h4>\n\n\n\n
        SELECT column1, column2, ...\nFROM table_name\nWHERE condition1 OR condition2;<\/code><\/pre>\n\n\n\n
        \u5b9e\u4f8b\uff1a\u67e5\u8be2\u6ee1\u8db3\u4efb\u4e00\u6761\u4ef6\u7684\u8bb0\u5f55<\/strong><\/h4>\n\n\n\n
        SELECT username, email\nFROM users\nWHERE user_id = 1 OR email = 'john@example.com';<\/code><\/pre>\n\n\n\n
          \n
        • \u8fd9\u4e2a\u67e5\u8be2\u5c06\u8fd4\u56de user_id<\/code> \u4e3a 1 \u6216 email<\/code> \u4e3a 'john@example.com'<\/code> \u7684\u7528\u6237\u7684 username<\/code> \u548c email<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n
          \n\n\n\n
          4. \u4f7f\u7528 BETWEEN<\/code> \u8fdb\u884c\u8303\u56f4\u67e5\u8be2<\/strong><\/h3>\n\n\n\n
          BETWEEN<\/code> \u7528\u4e8e\u68c0\u67e5\u67d0\u4e2a\u5b57\u6bb5\u7684\u503c\u662f\u5426\u5728\u6307\u5b9a\u7684\u8303\u56f4\u5185\uff08\u5305\u62ec\u8fb9\u754c\u503c\uff09\u3002<\/p>\n\n\n\n
          \u57fa\u672c\u8bed\u6cd5<\/strong><\/h4>\n\n\n\n
          SELECT column1, column2, ...\nFROM table_name\nWHERE column_name BETWEEN value1 AND value2;<\/code><\/pre>\n\n\n\n
          \u5b9e\u4f8b\uff1a\u67e5\u8be2 age<\/code> \u5728\u4e00\u5b9a\u8303\u56f4\u5185\u7684\u8bb0\u5f55<\/strong><\/h4>\n\n\n\n
          SELECT username, age\nFROM users\nWHERE age BETWEEN 18 AND 30;<\/code><\/pre>\n\n\n\n
            \n
          • \u8fd9\u4e2a\u67e5\u8be2\u8fd4\u56de age<\/code> \u5728 18 \u548c 30 \u4e4b\u95f4\uff08\u5305\u62ec 18 \u548c 30\uff09\u7684\u6240\u6709\u7528\u6237\u7684 username<\/code> \u548c age<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n
            \n\n\n\n
            5. \u4f7f\u7528 IN<\/code> \u8fdb\u884c\u591a\u503c\u5339\u914d<\/strong><\/h3>\n\n\n\n
            IN<\/code> \u7528\u4e8e\u68c0\u67e5\u67d0\u4e2a\u5b57\u6bb5\u7684\u503c\u662f\u5426\u5728\u4e00\u7ec4\u6307\u5b9a\u7684\u503c\u4e2d\u3002\u5b83\u7b49\u4ef7\u4e8e\u591a\u4e2a OR<\/code> \u6761\u4ef6\u3002<\/p>\n\n\n\n
            \u57fa\u672c\u8bed\u6cd5<\/strong><\/h4>\n\n\n\n
            SELECT column1, column2, ...\nFROM table_name\nWHERE column_name IN (value1, value2, value3, ...);<\/code><\/pre>\n\n\n\n
            \u5b9e\u4f8b\uff1a\u67e5\u8be2 user_id<\/code> \u5728\u6307\u5b9a\u503c\u8303\u56f4\u5185\u7684\u8bb0\u5f55<\/strong><\/h4>\n\n\n\n
            SELECT username, email\nFROM users\nWHERE user_id IN (1, 2, 3);<\/code><\/pre>\n\n\n\n
              \n
            • \u8fd9\u4e2a\u67e5\u8be2\u8fd4\u56de user_id<\/code> \u4e3a 1\u30012 \u6216 3 \u7684\u7528\u6237\u7684 username<\/code> \u548c email<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n
              \n\n\n\n
              6. \u4f7f\u7528 LIKE<\/code> \u8fdb\u884c\u6a21\u7cca\u5339\u914d<\/strong><\/h3>\n\n\n\n
              LIKE<\/code> \u7528\u4e8e\u8fdb\u884c\u6a21\u7cca\u67e5\u8be2\uff0c\u53ef\u4ee5\u5339\u914d\u90e8\u5206\u5b57\u7b26\u3002\u5e38\u7528\u7684\u901a\u914d\u7b26\u6709\uff1a<\/p>\n\n\n\n
                \n
              • %<\/code>\uff1a\u5339\u914d\u96f6\u4e2a\u6216\u591a\u4e2a\u5b57\u7b26\u3002<\/li>\n\n\n\n
              • _<\/code>\uff1a\u5339\u914d\u4e00\u4e2a\u5b57\u7b26\u3002<\/li>\n<\/ul>\n\n\n\n
                \u57fa\u672c\u8bed\u6cd5<\/strong><\/h4>\n\n\n\n
                SELECT column1, column2, ...\nFROM table_name\nWHERE column_name LIKE pattern;<\/code><\/pre>\n\n\n\n
                \u5b9e\u4f8b\uff1a\u67e5\u8be2 username<\/code> \u4e2d\u5305\u542b\u7279\u5b9a\u5b57\u7b26\u4e32\u7684\u8bb0\u5f55<\/strong><\/h4>\n\n\n\n
                SELECT username, email\nFROM users\nWHERE username LIKE '%john%';<\/code><\/pre>\n\n\n\n
                  \n
                • \u8fd9\u4e2a\u67e5\u8be2\u8fd4\u56de username<\/code> \u4e2d\u5305\u542b john<\/code> \u7684\u6240\u6709\u7528\u6237\u3002%<\/code> \u8868\u793a\u96f6\u4e2a\u6216\u591a\u4e2a\u5b57\u7b26\u3002<\/li>\n<\/ul>\n\n\n\n
                  \u5b9e\u4f8b\uff1a\u67e5\u8be2\u4ee5\u7279\u5b9a\u5b57\u7b26\u5f00\u5934\u7684\u8bb0\u5f55<\/strong><\/h4>\n\n\n\n
                  SELECT username, email\nFROM users\nWHERE username LIKE 'john%';<\/code><\/pre>\n\n\n\n
                    \n
                  • \u8fd9\u4e2a\u67e5\u8be2\u8fd4\u56de\u6240\u6709\u4ee5 john<\/code> \u5f00\u5934\u7684 username<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n
                    \u5b9e\u4f8b\uff1a\u67e5\u8be2 email<\/code> \u4e2d\u5305\u542b\u67d0\u4e2a\u5b57\u7b26\u7684\u8bb0\u5f55<\/strong><\/h4>\n\n\n\n
                    SELECT username, email\nFROM users\nWHERE email LIKE '%@example.com';<\/code><\/pre>\n\n\n\n
                      \n
                    • \u8fd9\u4e2a\u67e5\u8be2\u8fd4\u56de email<\/code> \u4e2d\u5305\u542b @example.com<\/code> \u7684\u6240\u6709\u7528\u6237\u3002<\/li>\n<\/ul>\n\n\n\n
                      \n\n\n\n
                      7. \u4f7f\u7528 IS NULL<\/code> \u6216 IS NOT NULL<\/code> \u68c0\u67e5\u7a7a\u503c<\/strong><\/h3>\n\n\n\n
                      IS NULL<\/code> \u7528\u4e8e\u68c0\u67e5\u67d0\u4e2a\u5b57\u6bb5\u662f\u5426\u4e3a NULL<\/code>\uff0cIS NOT NULL<\/code> \u7528\u4e8e\u68c0\u67e5\u5b57\u6bb5\u662f\u5426\u4e0d\u662f NULL<\/code>\u3002<\/p>\n\n\n\n
                      \u57fa\u672c\u8bed\u6cd5<\/strong><\/h4>\n\n\n\n
                      SELECT column1, column2, ...\nFROM table_name\nWHERE column_name IS NULL;<\/code><\/pre>\n\n\n\n
                      \u5b9e\u4f8b\uff1a\u67e5\u8be2 email<\/code> \u4e3a NULL<\/code> \u7684\u8bb0\u5f55<\/strong><\/h4>\n\n\n\n
                      SELECT username\nFROM users\nWHERE email IS NULL;<\/code><\/pre>\n\n\n\n
                        \n
                      • \u8fd9\u4e2a\u67e5\u8be2\u8fd4\u56de email<\/code> \u4e3a NULL<\/code> \u7684\u6240\u6709\u7528\u6237\u7684 username<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n
                        \u5b9e\u4f8b\uff1a\u67e5\u8be2 email<\/code> \u4e0d\u4e3a NULL<\/code> \u7684\u8bb0\u5f55<\/strong><\/h4>\n\n\n\n
                        SELECT username\nFROM users\nWHERE email IS NOT NULL;<\/code><\/pre>\n\n\n\n
                          \n
                        • \u8fd9\u4e2a\u67e5\u8be2\u8fd4\u56de email<\/code> \u4e0d\u4e3a NULL<\/code> \u7684\u6240\u6709\u7528\u6237\u7684 username<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n
                          \n\n\n\n
                          8. \u4f7f\u7528 EXISTS<\/code> \u68c0\u67e5\u5b50\u67e5\u8be2\u662f\u5426\u8fd4\u56de\u8bb0\u5f55<\/strong><\/h3>\n\n\n\n
                          EXISTS<\/code> \u7528\u4e8e\u68c0\u67e5\u5b50\u67e5\u8be2\u662f\u5426\u8fd4\u56de\u81f3\u5c11\u4e00\u6761\u8bb0\u5f55\u3002\u5982\u679c\u5b50\u67e5\u8be2\u8fd4\u56de\u81f3\u5c11\u4e00\u884c\uff0cEXISTS<\/code> \u6761\u4ef6\u4e3a TRUE<\/code>\uff0c\u5426\u5219\u4e3a FALSE<\/code>\u3002<\/p>\n\n\n\n
                          \u57fa\u672c\u8bed\u6cd5<\/strong><\/h4>\n\n\n\n
                          SELECT column1, column2, ...\nFROM table_name\nWHERE EXISTS (subquery);<\/code><\/pre>\n\n\n\n
                          \u5b9e\u4f8b\uff1a\u68c0\u67e5\u662f\u5426\u5b58\u5728\u7279\u5b9a\u6761\u4ef6\u7684\u8ba2\u5355<\/strong><\/h4>\n\n\n\n
                          \u5047\u8bbe\u4f60\u6709\u4e00\u4e2a users<\/code> \u8868\u548c\u4e00\u4e2a orders<\/code> \u8868\uff0corders<\/code> \u8868\u4e2d\u6709\u4e00\u4e2a user_id<\/code> \u5b57\u6bb5\u3002\u4f60\u53ef\u4ee5\u67e5\u8be2\u6240\u6709\u6709\u8ba2\u5355\u7684\u7528\u6237\uff1a<\/p>\n\n\n\n
                          SELECT username\nFROM users\nWHERE EXISTS (SELECT 1 FROM orders WHERE orders.user_id = users.user_id);<\/code><\/pre>\n\n\n\n
                            \n
                          • \u8fd9\u4e2a\u67e5\u8be2\u8fd4\u56de\u6240\u6709\u81f3\u5c11\u6709\u4e00\u6761\u8ba2\u5355\u7684\u7528\u6237\u7684 username<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n
                            \n\n\n\n
                            9. \u4f7f\u7528 NOT<\/code> \u5426\u5b9a\u6761\u4ef6<\/strong><\/h3>\n\n\n\n
                            NOT<\/code> \u7528\u4e8e\u5426\u5b9a\u6761\u4ef6\uff0c\u53ef\u4ee5\u548c\u5176\u4ed6\u6761\u4ef6\u64cd\u4f5c\u7b26\uff08\u5982 BETWEEN<\/code>, IN<\/code>, LIKE<\/code> \u7b49\uff09\u4e00\u8d77\u4f7f\u7528\u3002<\/p>\n\n\n\n
                            \u57fa\u672c\u8bed\u6cd5<\/strong><\/h4>\n\n\n\n
                            SELECT column1, column2, ...\nFROM table_name\nWHERE NOT condition;<\/code><\/pre>\n\n\n\n
                            \u5b9e\u4f8b\uff1a\u67e5\u8be2 age<\/code> \u4e0d\u5728\u67d0\u4e2a\u8303\u56f4\u5185\u7684\u8bb0\u5f55<\/strong><\/h4>\n\n\n\n
                            SELECT username, age\nFROM users\nWHERE NOT age BETWEEN 18 AND 30;<\/code><\/pre>\n\n\n\n
                              \n
                            • \u8fd9\u4e2a\u67e5\u8be2\u8fd4\u56de age<\/code> \u4e0d\u5728 18 \u548c 30 \u4e4b\u95f4\u7684\u6240\u6709\u7528\u6237\u3002<\/li>\n<\/ul>\n\n\n\n
                              \u5b9e\u4f8b\uff1a\u67e5\u8be2 email<\/code> \u4e0d\u5305\u542b\u7279\u5b9a\u5b57\u7b26\u4e32\u7684\u8bb0\u5f55<\/strong><\/h4>\n\n\n\n
                              SELECT username, email\nFROM users\nWHERE email NOT LIKE '%@example.com';<\/code><\/pre>\n\n\n\n
                                \n
                              • \u8fd9\u4e2a\u67e5\u8be2\u8fd4\u56de email<\/code> \u4e0d\u5305\u542b @example.com<\/code> \u7684\u6240\u6709\u7528\u6237\u3002<\/li>\n<\/ul>\n\n\n\n
                                \n\n\n\n
                                \u603b\u7ed3<\/h3>\n\n\n\n
                                \u5728 MySQL \u4e2d\uff0cWHERE<\/code> \u5b50\u53e5\u662f\u7528\u6765\u8fc7\u6ee4\u67e5\u8be2\u7ed3\u679c\u7684\u5f3a\u5927\u5de5\u5177\u3002\u5e38\u7528\u7684\u6761\u4ef6\u64cd\u4f5c\u7b26\u548c\u5173\u952e\u5b57\u5305\u62ec\uff1a<\/p>\n\n\n\n
                                  \n
                                1. =<\/code><\/strong>\uff1a\u7b49\u4e8e\u3002<\/li>\n\n\n\n
                                2. AND<\/code><\/strong>\u3001OR<\/code><\/strong>\uff1a\u8fde\u63a5\u591a\u4e2a\u6761\u4ef6\u3002<\/li>\n\n\n\n
                                3. BETWEEN<\/code><\/strong>\uff1a\u8303\u56f4\u67e5\u8be2\u3002<\/li>\n\n\n\n
                                4. IN<\/code><\/strong>\uff1a\u591a\u503c\u5339\u914d\u3002<\/li>\n\n\n\n
                                5. LIKE<\/code><\/strong>\uff1a\u6a21\u7cca\u5339\u914d\u3002<\/li>\n\n\n\n
                                6. IS NULL<\/code><\/strong>\u3001IS NOT NULL<\/code><\/strong>\uff1a\u68c0\u67e5\u7a7a\u503c\u3002<\/li>\n\n\n\n
                                7. EXISTS<\/code><\/strong>\uff1a\u5b50\u67e5\u8be2\u662f\u5426\u8fd4\u56de\u8bb0\u5f55\u3002<\/li>\n\n\n\n
                                8. NOT<\/code><\/strong>\uff1a\u5426\u5b9a\u6761\u4ef6\u3002<\/li>\n<\/ol>\n\n\n\n
                                  \u901a\u8fc7\u8fd9\u4e9b\u6761\u4ef6\uff0c\u4f60\u53ef\u4ee5\u7075\u6d3b\u5730\u4ece\u6570\u636e\u5e93\u4e2d\u7b5b\u9009\u51fa\u6ee1\u8db3\u7279\u5b9a\u9700\u6c42\u7684\u6570\u636e\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
                                  \u5728 MySQL \u4e2d\uff0cWHERE \u5b50\u53e5\u7528\u4e8e\u8fc7\u6ee4\u67e5\u8be2\u7ed3\u679c\uff0c\u53ea\u8fd4\u56de\u6ee1\u8db3\u7279\u5b9a\u6761\u4ef6\u7684\u8bb0\u5f55\u3002\u5b83\u901a\u5e38\u4e0e SELECT\u3001UPD […]<\/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-1768","post","type-post","status-publish","format-standard","hentry","category-mysql"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/1768","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=1768"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/1768\/revisions"}],"predecessor-version":[{"id":1769,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/1768\/revisions\/1769"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=1768"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=1768"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=1768"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}