{"id":2318,"date":"2025-03-04T08:36:39","date_gmt":"2025-03-04T00:36:39","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=2318"},"modified":"2025-03-04T08:36:39","modified_gmt":"2025-03-04T00:36:39","slug":"sqlite-select-%e8%af%ad%e5%8f%a5","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/03\/04\/sqlite-select-%e8%af%ad%e5%8f%a5\/","title":{"rendered":"SQLite SELECT \u8bed\u53e5"},"content":{"rendered":"\n
\n

SELECT<\/code> \u8bed\u53e5\u7528\u4e8e\u4ece SQLite \u6570\u636e\u5e93\u4e2d\u67e5\u8be2\u6570\u636e\u3002\u5b83\u662f\u6700\u5e38\u7528\u7684 SQL \u8bed\u53e5\u4e4b\u4e00\uff0c\u53ef\u4ee5\u6839\u636e\u6761\u4ef6\u9009\u62e9\u8868\u4e2d\u7684\u4e00\u4e2a\u6216\u591a\u4e2a\u5217\u3002<\/p>\n<\/blockquote>\n\n\n\n

\n\n\n\n

1. \u57fa\u672c SELECT \u8bed\u6cd5<\/strong><\/h2>\n\n\n\n
SELECT column1, column2, ...\nFROM table_name\nWHERE condition;<\/code><\/pre>\n\n\n\n
    \n
  • column1, column2, ...<\/code>\uff1a\u8981\u67e5\u8be2\u7684\u5217\u3002\u5982\u679c\u67e5\u8be2\u6240\u6709\u5217\uff0c\u53ef\u4ee5\u4f7f\u7528 *<\/code>\u3002<\/li>\n\n\n\n
  • table_name<\/code>\uff1a\u8981\u67e5\u8be2\u6570\u636e\u7684\u8868\u540d\u3002<\/li>\n\n\n\n
  • condition<\/code>\uff1a\u53ef\u9009\u7684\u8fc7\u6ee4\u6761\u4ef6\uff0c\u7528\u4e8e\u9650\u5236\u67e5\u8be2\u7684\u8bb0\u5f55\u3002<\/li>\n<\/ul>\n\n\n\n
    \n\n\n\n
    2. \u67e5\u8be2\u6240\u6709\u5217<\/strong><\/h2>\n\n\n\n
    \u8bed\u6cd5<\/strong><\/h3>\n\n\n\n
    SELECT * FROM table_name;<\/code><\/pre>\n\n\n\n
    *<\/code> \u8868\u793a\u67e5\u8be2\u6240\u6709\u5217\u7684\u6570\u636e\u3002<\/p>\n\n\n\n
    \u793a\u4f8b\uff1a\u67e5\u8be2\u6240\u6709\u7528\u6237\u6570\u636e<\/strong><\/h3>\n\n\n\n
    SELECT * FROM users;<\/code><\/pre>\n\n\n\n
    \u8fd9\u6761\u8bed\u53e5\u4f1a\u8fd4\u56de users<\/code> \u8868\u4e2d\u6240\u6709\u5217\u548c\u6240\u6709\u8bb0\u5f55\u3002<\/p>\n\n\n\n
    \n\n\n\n
    3. \u67e5\u8be2\u6307\u5b9a\u5217<\/strong><\/h2>\n\n\n\n
    \u8bed\u6cd5<\/strong><\/h3>\n\n\n\n
    SELECT column1, column2, ... FROM table_name;<\/code><\/pre>\n\n\n\n
    \u4f60\u53ef\u4ee5\u6307\u5b9a\u67e5\u8be2\u67d0\u4e9b\u5217\u3002<\/p>\n\n\n\n
    \u793a\u4f8b\uff1a\u67e5\u8be2\u7528\u6237\u7684 name<\/code> \u548c age<\/code><\/strong><\/h3>\n\n\n\n
    SELECT name, age FROM users;<\/code><\/pre>\n\n\n\n
    \u8fd9\u6761\u8bed\u53e5\u53ea\u4f1a\u8fd4\u56de users<\/code> \u8868\u4e2d\u7684 name<\/code> \u548c age<\/code> \u5217\u3002<\/p>\n\n\n\n
    \n\n\n\n
    4. \u4f7f\u7528 WHERE \u5b50\u53e5\u8fdb\u884c\u6761\u4ef6\u8fc7\u6ee4<\/strong><\/h2>\n\n\n\n
    WHERE<\/code> \u5b50\u53e5\u7528\u4e8e\u6307\u5b9a\u8fc7\u6ee4\u6761\u4ef6\uff0c\u53ef\u4ee5\u57fa\u4e8e\u5217\u503c\u8fdb\u884c\u7b5b\u9009\u3002<\/p>\n\n\n\n
    \u8bed\u6cd5<\/strong><\/h3>\n\n\n\n
    SELECT column1, column2, ...\nFROM table_name\nWHERE condition;<\/code><\/pre>\n\n\n\n
    \u793a\u4f8b\uff1a\u67e5\u8be2\u5e74\u9f84\u5927\u4e8e 30 \u7684\u7528\u6237<\/strong><\/h3>\n\n\n\n
    SELECT name, age FROM users WHERE age > 30;<\/code><\/pre>\n\n\n\n
    \u8fd9\u5c06\u8fd4\u56de age<\/code> \u5927\u4e8e 30 \u7684\u6240\u6709\u7528\u6237\u7684 name<\/code> \u548c age<\/code>\u3002<\/p>\n\n\n\n
    \u66f4\u591a\u6761\u4ef6\u64cd\u4f5c<\/strong><\/h3>\n\n\n\n
      \n
    • =<\/code>\uff1a\u7b49\u4e8e<\/li>\n\n\n\n
    • ><\/code>\uff1a\u5927\u4e8e<\/li>\n\n\n\n
    • <<\/code>\uff1a\u5c0f\u4e8e<\/li>\n\n\n\n
    • >=<\/code>\uff1a\u5927\u4e8e\u6216\u7b49\u4e8e<\/li>\n\n\n\n
    • <=<\/code>\uff1a\u5c0f\u4e8e\u6216\u7b49\u4e8e<\/li>\n\n\n\n
    • <><\/code> \u6216 !=<\/code>\uff1a\u4e0d\u7b49\u4e8e<\/li>\n\n\n\n
    • BETWEEN ... AND ...<\/code>\uff1a\u8303\u56f4\u67e5\u627e<\/li>\n\n\n\n
    • IN (...)<\/code>\uff1a\u5339\u914d\u591a\u4e2a\u503c<\/li>\n\n\n\n
    • LIKE<\/code>\uff1a\u6a21\u7cca\u5339\u914d<\/li>\n\n\n\n
    • IS NULL<\/code>\uff1a\u67e5\u627e\u7a7a\u503c<\/li>\n<\/ul>\n\n\n\n
      \n\n\n\n
      5. \u4f7f\u7528 ORDER BY \u6392\u5e8f<\/strong><\/h2>\n\n\n\n
      ORDER BY<\/code> \u5b50\u53e5\u7528\u4e8e\u5bf9\u67e5\u8be2\u7ed3\u679c\u8fdb\u884c\u6392\u5e8f\uff0c\u53ef\u4ee5\u6309\u5347\u5e8f\uff08ASC<\/code>\uff09\u6216\u964d\u5e8f\uff08DESC<\/code>\uff09\u6392\u5e8f\u3002<\/p>\n\n\n\n
      \u8bed\u6cd5<\/strong><\/h3>\n\n\n\n
      SELECT column1, column2, ...\nFROM table_name\nORDER BY column_name [ASC | DESC];<\/code><\/pre>\n\n\n\n
        \n
      • ASC<\/code>\uff1a\u5347\u5e8f\uff08\u9ed8\u8ba4\uff09\u3002<\/li>\n\n\n\n
      • DESC<\/code>\uff1a\u964d\u5e8f\u3002<\/li>\n<\/ul>\n\n\n\n
        \u793a\u4f8b\uff1a\u6309\u5e74\u9f84\u5347\u5e8f\u67e5\u8be2\u7528\u6237<\/strong><\/h3>\n\n\n\n
        SELECT name, age FROM users ORDER BY age ASC;<\/code><\/pre>\n\n\n\n
        \u8fd9\u4f1a\u6309\u7167 age<\/code> \u5217\u7684\u5347\u5e8f\u8fd4\u56de\u6240\u6709\u7528\u6237\u3002<\/p>\n\n\n\n
        \u793a\u4f8b\uff1a\u6309\u5e74\u9f84\u964d\u5e8f\u67e5\u8be2\u7528\u6237<\/strong><\/h3>\n\n\n\n
        SELECT name, age FROM users ORDER BY age DESC;<\/code><\/pre>\n\n\n\n
        \u8fd9\u4f1a\u6309\u7167 age<\/code> \u5217\u7684\u964d\u5e8f\u8fd4\u56de\u6240\u6709\u7528\u6237\u3002<\/p>\n\n\n\n
        \n\n\n\n
        6. \u4f7f\u7528 LIMIT \u9650\u5236\u67e5\u8be2\u7ed3\u679c<\/strong><\/h2>\n\n\n\n
        LIMIT<\/code> \u5b50\u53e5\u7528\u4e8e\u9650\u5236\u67e5\u8be2\u8fd4\u56de\u7684\u8bb0\u5f55\u6570\u3002<\/p>\n\n\n\n
        \u8bed\u6cd5<\/strong><\/h3>\n\n\n\n
        SELECT column1, column2, ...\nFROM table_name\nLIMIT number;<\/code><\/pre>\n\n\n\n
        \u793a\u4f8b\uff1a\u8fd4\u56de\u524d 5 \u6761\u7528\u6237\u6570\u636e<\/strong><\/h3>\n\n\n\n
        SELECT name, age FROM users LIMIT 5;<\/code><\/pre>\n\n\n\n
        \u8fd9\u4f1a\u8fd4\u56de users<\/code> \u8868\u4e2d\u7684\u524d 5 \u6761\u8bb0\u5f55\u3002<\/p>\n\n\n\n
        \n\n\n\n
        7. \u805a\u5408\u51fd\u6570<\/strong><\/h2>\n\n\n\n
        SQLite \u63d0\u4f9b\u4e86\u591a\u79cd\u805a\u5408\u51fd\u6570\uff0c\u5982 COUNT()<\/code>, SUM()<\/code>, AVG()<\/code>, MAX()<\/code>, MIN()<\/code> \u7b49\u3002<\/p>\n\n\n\n
        \u793a\u4f8b\uff1a\u67e5\u8be2\u7528\u6237\u603b\u6570<\/strong><\/h3>\n\n\n\n
        SELECT COUNT(*) FROM users;<\/code><\/pre>\n\n\n\n
        \u8fd9\u4f1a\u8fd4\u56de users<\/code> \u8868\u4e2d\u7684\u8bb0\u5f55\u6570\u3002<\/p>\n\n\n\n
        \u793a\u4f8b\uff1a\u67e5\u8be2\u7528\u6237\u7684\u5e73\u5747\u5e74\u9f84<\/strong><\/h3>\n\n\n\n
        SELECT AVG(age) FROM users;<\/code><\/pre>\n\n\n\n
        \u8fd9\u4f1a\u8fd4\u56de users<\/code> \u8868\u4e2d\u6240\u6709\u7528\u6237\u7684\u5e73\u5747\u5e74\u9f84\u3002<\/p>\n\n\n\n
        \n\n\n\n
        8. \u4f7f\u7528 GROUP BY \u5b50\u53e5\u5206\u7ec4<\/strong><\/h2>\n\n\n\n
        GROUP BY<\/code> \u7528\u4e8e\u5c06\u67e5\u8be2\u7ed3\u679c\u6309\u67d0\u4e00\u5217\u5206\u7ec4\uff0c\u5e76\u53ef\u4ee5\u4e0e\u805a\u5408\u51fd\u6570\u7ed3\u5408\u4f7f\u7528\u3002<\/p>\n\n\n\n
        \u8bed\u6cd5<\/strong><\/h3>\n\n\n\n
        SELECT column, AGGREGATE_FUNCTION(column)\nFROM table_name\nGROUP BY column;<\/code><\/pre>\n\n\n\n
        \u793a\u4f8b\uff1a\u6309\u5e74\u9f84\u5206\u7ec4\u5e76\u7edf\u8ba1\u6bcf\u4e2a\u5e74\u9f84\u6bb5\u7684\u7528\u6237\u6570<\/strong><\/h3>\n\n\n\n
        SELECT age, COUNT(*) FROM users GROUP BY age;<\/code><\/pre>\n\n\n\n
        \u8fd9\u4f1a\u6309 age<\/code> \u5217\u5c06\u7528\u6237\u5206\u7ec4\uff0c\u5e76\u7edf\u8ba1\u6bcf\u4e2a\u5e74\u9f84\u6bb5\u7684\u7528\u6237\u6570\u91cf\u3002<\/p>\n\n\n\n
        \n\n\n\n
        9. \u4f7f\u7528 JOIN \u8fde\u63a5\u591a\u4e2a\u8868<\/strong><\/h2>\n\n\n\n
        SQLite \u652f\u6301\u591a\u79cd\u8fde\u63a5\u64cd\u4f5c\uff0c\u5982 INNER JOIN<\/code>, LEFT JOIN<\/code>, RIGHT JOIN<\/code>\uff08RIGHT JOIN<\/code> \u4e0d\u88ab SQLite \u652f\u6301\uff09\uff0c\u53ef\u4ee5\u5c06\u591a\u4e2a\u8868\u7684\u6570\u636e\u7ed3\u5408\u8d77\u6765\u67e5\u8be2\u3002<\/p>\n\n\n\n
        \u793a\u4f8b\uff1a\u4f7f\u7528 INNER JOIN \u67e5\u8be2\u8ba2\u5355\u53ca\u7528\u6237\u4fe1\u606f<\/strong><\/h3>\n\n\n\n
        \u5047\u8bbe\u6709\u4e24\u4e2a\u8868 users<\/code> \u548c orders<\/code>\uff0corders<\/code> \u8868\u5305\u542b user_id<\/code> \u5217\uff0c\u7528\u4e8e\u5173\u8054 users<\/code> \u8868\u7684 id<\/code>\u3002<\/p>\n\n\n\n
        SELECT users.name, orders.order_id\nFROM users\nINNER JOIN orders ON users.id = orders.user_id;<\/code><\/pre>\n\n\n\n
        \u8fd9\u6761\u8bed\u53e5\u4f1a\u8fd4\u56de\u6240\u6709\u6709\u8ba2\u5355\u7684\u7528\u6237\u7684\u59d3\u540d\u548c\u8ba2\u5355 ID\u3002<\/p>\n\n\n\n
        \n\n\n\n
        10. \u5728 Python \u4e2d\u4f7f\u7528 SELECT<\/strong><\/h2>\n\n\n\n
        \u5728 Python \u4e2d\uff0c\u4f60\u53ef\u4ee5\u4f7f\u7528 sqlite3<\/code> \u5e93\u6267\u884c SELECT<\/code> \u8bed\u53e5\u3002<\/p>\n\n\n\n
        \u793a\u4f8b\uff1a\u67e5\u8be2\u6240\u6709\u7528\u6237\u6570\u636e<\/strong><\/h3>\n\n\n\n
        import sqlite3\n\n# \u8fde\u63a5\u5230\u6570\u636e\u5e93\nconn = sqlite3.connect('my_database.db')\ncursor = conn.cursor()\n\n# \u6267\u884c SELECT \u67e5\u8be2\ncursor.execute(\"SELECT name, age FROM users\")\n\n# \u83b7\u53d6\u6240\u6709\u7ed3\u679c\nrows = cursor.fetchall()\nfor row in rows:\n    print(row)\n\n# \u5173\u95ed\u8fde\u63a5\nconn.close()<\/code><\/pre>\n\n\n\n
        \n\n\n\n
        \u603b\u7ed3<\/strong><\/h2>\n\n\n\n
          \n
        • \u57fa\u672c\u67e5\u8be2<\/strong>\uff1a\u4f7f\u7528 SELECT<\/code> \u67e5\u8be2\u8868\u4e2d\u7684\u6570\u636e\u3002<\/li>\n\n\n\n
        • WHERE \u5b50\u53e5<\/strong>\uff1a\u7528\u4e8e\u6dfb\u52a0\u67e5\u8be2\u6761\u4ef6\u3002<\/li>\n\n\n\n
        • ORDER BY<\/strong>\uff1a\u7528\u4e8e\u6392\u5e8f\u67e5\u8be2\u7ed3\u679c\u3002<\/li>\n\n\n\n
        • LIMIT<\/strong>\uff1a\u7528\u4e8e\u9650\u5236\u67e5\u8be2\u7ed3\u679c\u7684\u6570\u91cf\u3002<\/li>\n\n\n\n
        • \u805a\u5408\u51fd\u6570<\/strong>\uff1a\u7528\u4e8e\u8ba1\u7b97\u5982\u603b\u6570\u3001\u5e73\u5747\u503c\u7b49\u3002<\/li>\n\n\n\n
        • JOIN \u64cd\u4f5c<\/strong>\uff1a\u7528\u4e8e\u8fde\u63a5\u591a\u4e2a\u8868\u67e5\u8be2\u6570\u636e\u3002<\/li>\n\n\n\n
        • GROUP BY<\/strong>\uff1a\u7528\u4e8e\u5206\u7ec4\u548c\u805a\u5408\u67e5\u8be2\u3002<\/li>\n<\/ul>\n\n\n\n
          \u66f4\u591a\u8be6\u7ec6\u5185\u5bb9\u8bf7\u5173\u6ce8\u5176\u4ed6\u76f8\u5173\u6587\u7ae0\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
          SELECT \u8bed\u53e5\u7528\u4e8e\u4ece SQLite \u6570\u636e\u5e93\u4e2d\u67e5\u8be2\u6570\u636e\u3002\u5b83\u662f\u6700\u5e38\u7528\u7684 SQL \u8bed\u53e5\u4e4b\u4e00\uff0c\u53ef\u4ee5\u6839\u636e\u6761\u4ef6\u9009\u62e9\u8868\u4e2d […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[76],"tags":[],"class_list":["post-2318","post","type-post","status-publish","format-standard","hentry","category-sqlite"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2318","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=2318"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2318\/revisions"}],"predecessor-version":[{"id":2319,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2318\/revisions\/2319"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=2318"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=2318"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=2318"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}