{"id":1743,"date":"2025-02-16T09:13:21","date_gmt":"2025-02-16T01:13:21","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=1743"},"modified":"2025-02-16T09:13:21","modified_gmt":"2025-02-16T01:13:21","slug":"sql-round-%e5%87%bd%e6%95%b0","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/02\/16\/sql-round-%e5%87%bd%e6%95%b0\/","title":{"rendered":"SQL ROUND() \u51fd\u6570"},"content":{"rendered":"\n

ROUND()<\/code> \u662f SQL \u4e2d\u7684\u4e00\u4e2a\u51fd\u6570\uff0c\u7528\u4e8e\u5c06\u6570\u503c\u56db\u820d\u4e94\u5165\u5230\u6307\u5b9a\u7684\u5c0f\u6570\u4f4d\u6570\u3002\u8fd9\u4e2a\u51fd\u6570\u5e38\u7528\u4e8e\u6570\u5b57\u8ba1\u7b97\u4e2d\uff0c\u4ee5\u4fbf\u5bf9\u6570\u636e\u8fdb\u884c\u7cbe\u786e\u63a7\u5236\u3002<\/p>\n\n\n\n

1. ROUND()<\/code> \u7684\u57fa\u672c\u8bed\u6cd5<\/strong><\/h3>\n\n\n\n
ROUND(number, decimal_places);<\/code><\/pre>\n\n\n\n
    \n
  • number<\/code>\uff1a\u8981\u8fdb\u884c\u56db\u820d\u4e94\u5165\u7684\u6570\u503c\u3002<\/li>\n\n\n\n
  • decimal_places<\/code>\uff1a\u8981\u4fdd\u7559\u7684\u5c0f\u6570\u4f4d\u6570\u3002\u5982\u679c\u7701\u7565\u8be5\u53c2\u6570\uff0c\u9ed8\u8ba4\u5c06\u56db\u820d\u4e94\u5165\u4e3a\u6574\u6570\u3002<\/li>\n<\/ul>\n\n\n\n
    2. ROUND()<\/code> \u7684\u793a\u4f8b<\/strong><\/h3>\n\n\n\n
    \u5047\u8bbe\u4f60\u6709\u4e00\u4e2a\u540d\u4e3a sales<\/code> \u7684\u8868\uff0c\u5305\u542b\u4ee5\u4e0b\u6570\u636e\uff1a<\/p>\n\n\n\n
    sale_id<\/th>sale_amount<\/th><\/tr><\/thead>
    1<\/td>123.456<\/td><\/tr>
    2<\/td>78.912<\/td><\/tr>
    3<\/td>54.789<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
    2.1 \u56db\u820d\u4e94\u5165\u5230\u4e24\u4f4d\u5c0f\u6570<\/strong><\/h4>\n\n\n\n
    \u5982\u679c\u4f60\u5e0c\u671b\u5c06 sale_amount<\/code> \u5217\u4e2d\u7684\u6570\u5b57\u56db\u820d\u4e94\u5165\u5230\u4e24\u4f4d\u5c0f\u6570\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b SQL \u67e5\u8be2\uff1a<\/p>\n\n\n\n
    SELECT sale_id, ROUND(sale_amount, 2) AS rounded_amount\nFROM sales;<\/code><\/pre>\n\n\n\n
    \u67e5\u8be2\u7ed3\u679c<\/strong>\uff1a<\/p>\n\n\n\n
    sale_id<\/th>rounded_amount<\/th><\/tr><\/thead>
    1<\/td>123.46<\/td><\/tr>
    2<\/td>78.91<\/td><\/tr>
    3<\/td>54.79<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
    \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0cROUND(sale_amount, 2)<\/code> \u5c06\u6bcf\u4e2a sale_amount<\/code> \u7684\u6570\u503c\u56db\u820d\u4e94\u5165\u5230\u4e24\u4f4d\u5c0f\u6570\u3002<\/p>\n\n\n\n
    2.2 \u56db\u820d\u4e94\u5165\u5230\u6574\u6570<\/strong><\/h4>\n\n\n\n
    \u5982\u679c\u4f60\u53ea\u60f3\u4fdd\u7559\u6574\u6570\u90e8\u5206\uff0c\u53ef\u4ee5\u7701\u7565 decimal_places<\/code> \u53c2\u6570\uff1a<\/p>\n\n\n\n
    SELECT sale_id, ROUND(sale_amount) AS rounded_amount\nFROM sales;<\/code><\/pre>\n\n\n\n
    \u67e5\u8be2\u7ed3\u679c<\/strong>\uff1a<\/p>\n\n\n\n
    sale_id<\/th>rounded_amount<\/th><\/tr><\/thead>
    1<\/td>123<\/td><\/tr>
    2<\/td>79<\/td><\/tr>
    3<\/td>55<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
    \u8fd9\u91cc\uff0cROUND(sale_amount)<\/code> \u5c06 sale_amount<\/code> \u7684\u6570\u503c\u56db\u820d\u4e94\u5165\u5230\u6574\u6570\u3002<\/p>\n\n\n\n
    2.3 \u56db\u820d\u4e94\u5165\u5230\u8d1f\u6570\u7684\u5c0f\u6570\u4f4d<\/strong><\/h4>\n\n\n\n
    \u4f60\u8fd8\u53ef\u4ee5\u5c06 decimal_places<\/code> \u8bbe\u7f6e\u4e3a\u8d1f\u6570\uff0c\u6765\u56db\u820d\u4e94\u5165\u5230\u6574\u6570\u7684\u67d0\u4e2a\u4f4d\u7f6e\u3002\u4f8b\u5982\uff0c\u56db\u820d\u4e94\u5165\u5230\u6700\u63a5\u8fd1\u7684 10\uff1a<\/p>\n\n\n\n
    SELECT sale_id, ROUND(sale_amount, -1) AS rounded_amount\nFROM sales;<\/code><\/pre>\n\n\n\n
    \u67e5\u8be2\u7ed3\u679c<\/strong>\uff1a<\/p>\n\n\n\n
    sale_id<\/th>rounded_amount<\/th><\/tr><\/thead>
    1<\/td>120<\/td><\/tr>
    2<\/td>80<\/td><\/tr>
    3<\/td>50<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
    \u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0cROUND(sale_amount, -1)<\/code> \u5c06\u6bcf\u4e2a sale_amount<\/code> \u56db\u820d\u4e94\u5165\u5230\u6700\u63a5\u8fd1\u7684 10\u3002<\/p>\n\n\n\n
    3. ROUND()<\/code> \u51fd\u6570\u7684\u5e38\u89c1\u95ee\u9898\u53ca\u89e3\u51b3\u65b9\u6848<\/strong><\/h3>\n\n\n\n
    3.1 \u56db\u820d\u4e94\u5165\u7684\u8fb9\u754c\u60c5\u51b5<\/strong><\/h4>\n\n\n\n
    ROUND()<\/code> \u51fd\u6570\u4f1a\u6309\u7167\u6807\u51c6\u7684\u56db\u820d\u4e94\u5165\u89c4\u5219\u5904\u7406\u6570\u5b57\uff1a<\/p>\n\n\n\n
      \n
    • \u5982\u679c\u5c0f\u6570\u70b9\u540e\u7b2c\u4e00\u4f4d\u6570\u5b57\u5c0f\u4e8e 5\uff0c\u5219\u820d\u53bb\u3002<\/li>\n\n\n\n
    • \u5982\u679c\u5c0f\u6570\u70b9\u540e\u7b2c\u4e00\u4f4d\u6570\u5b57\u5927\u4e8e\u6216\u7b49\u4e8e 5\uff0c\u5219\u8fdb\u4f4d\u3002<\/li>\n<\/ul>\n\n\n\n
      \u4f8b\u5982\uff1a<\/p>\n\n\n\n
      SELECT ROUND(123.445, 2);<\/code><\/pre>\n\n\n\n
      \u67e5\u8be2\u7ed3\u679c<\/strong>\uff1a<\/p>\n\n\n\n
      ROUND(123.445, 2)<\/th><\/tr><\/thead>
      123.45<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
      \u8fd9\u91cc\uff0c123.445<\/code> \u88ab\u56db\u820d\u4e94\u5165\u4e3a 123.45<\/code>\uff0c\u56e0\u4e3a\u7b2c\u4e8c\u4f4d\u5c0f\u6570\uff084\uff09\u540e\u9762\u7684\u7b2c\u4e09\u4f4d\uff085\uff09\u662f 5 \u6216\u66f4\u5927\uff0c\u6240\u4ee5\u4e0b\u820d\u3002<\/p>\n\n\n\n
      3.2 \u8d1f\u6570\u5904\u7406<\/strong><\/h4>\n\n\n\n
      \u5982\u679c\u4f60\u5bf9\u8d1f\u6570\u5e94\u7528 ROUND()<\/code>\uff0c\u5b83\u4ecd\u7136\u9075\u5faa\u56db\u820d\u4e94\u5165\u89c4\u5219\uff1a<\/p>\n\n\n\n
      SELECT ROUND(-123.456, 2);<\/code><\/pre>\n\n\n\n
      \u67e5\u8be2\u7ed3\u679c<\/strong>\uff1a<\/p>\n\n\n\n
      ROUND(-123.456, 2)<\/th><\/tr><\/thead>
      -123.46<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
      3.3 ROUND()<\/code> \u4e0e\u5176\u4ed6\u6570\u5b66\u51fd\u6570\u7684\u7ed3\u5408<\/strong><\/h4>\n\n\n\n
      \u4f60\u53ef\u4ee5\u5c06 ROUND()<\/code> \u51fd\u6570\u4e0e\u5176\u4ed6\u6570\u5b66\u51fd\u6570\uff08\u5982 AVG()<\/code>\u3001SUM()<\/code> \u7b49\uff09\u7ed3\u5408\u4f7f\u7528\u3002\u4f8b\u5982\uff0c\u8ba1\u7b97\u9500\u552e\u989d\u7684\u5e73\u5747\u503c\u5e76\u56db\u820d\u4e94\u5165\u5230\u4e24\u4f4d\u5c0f\u6570\uff1a<\/p>\n\n\n\n
      SELECT ROUND(AVG(sale_amount), 2) AS avg_sale\nFROM sales;<\/code><\/pre>\n\n\n\n
      \u67e5\u8be2\u7ed3\u679c<\/strong>\uff1a<\/p>\n\n\n\n
      avg_sale<\/th><\/tr><\/thead>
      85.39<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
      3.4 ROUND()<\/code> \u4e0e NULL<\/code> \u503c<\/strong><\/h4>\n\n\n\n
      \u5982\u679c\u4f20\u9012\u7ed9 ROUND()<\/code> \u7684\u53c2\u6570\u662f NULL<\/code>\uff0c\u5b83\u5c06\u8fd4\u56de NULL<\/code>\uff0c\u800c\u4e0d\u4f1a\u5f15\u53d1\u9519\u8bef\u3002\u4e3a\u9632\u6b62\u8fd9\u79cd\u60c5\u51b5\uff0c\u53ef\u4ee5\u4f7f\u7528 COALESCE()<\/code> \u6216 IFNULL()<\/code> \u7b49\u51fd\u6570\u6765\u5904\u7406 NULL<\/code> \u503c\uff1a<\/p>\n\n\n\n
      SELECT ROUND(COALESCE(sale_amount, 0), 2) AS rounded_amount\nFROM sales;<\/code><\/pre>\n\n\n\n
      4. \u603b\u7ed3<\/strong><\/h3>\n\n\n\n
        \n
      • ROUND()<\/code> \u51fd\u6570\u7528\u4e8e\u5c06\u6570\u503c\u56db\u820d\u4e94\u5165\u5230\u6307\u5b9a\u7684\u5c0f\u6570\u4f4d\u6570\u3002<\/li>\n\n\n\n
      • \u53ef\u4ee5\u6307\u5b9a\u5c0f\u6570\u4f4d\u6570\uff0c\u4e5f\u53ef\u4ee5\u7701\u7565\u8be5\u53c2\u6570\u6765\u56db\u820d\u4e94\u5165\u4e3a\u6574\u6570\u3002<\/li>\n\n\n\n
      • \u4e5f\u53ef\u4ee5\u4f7f\u7528\u8d1f\u6570\u4f5c\u4e3a decimal_places<\/code> \u6765\u56db\u820d\u4e94\u5165\u5230\u5341\u4f4d\u3001\u767e\u4f4d\u7b49\u3002<\/li>\n\n\n\n
      • ROUND()<\/code> \u9075\u5faa\u6807\u51c6\u56db\u820d\u4e94\u5165\u89c4\u5219\uff1a\u82e5\u5c0f\u6570\u70b9\u540e\u7b2c\u4e00\u4f4d\u5927\u4e8e\u7b49\u4e8e 5\uff0c\u5219\u8fdb\u4f4d\u3002<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"
        ROUND() \u662f SQL \u4e2d\u7684\u4e00\u4e2a\u51fd\u6570\uff0c\u7528\u4e8e\u5c06\u6570\u503c\u56db\u820d\u4e94\u5165\u5230\u6307\u5b9a\u7684\u5c0f\u6570\u4f4d\u6570\u3002\u8fd9\u4e2a\u51fd\u6570\u5e38\u7528\u4e8e\u6570\u5b57\u8ba1\u7b97\u4e2d\uff0c\u4ee5\u4fbf\u5bf9 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[36],"tags":[],"class_list":["post-1743","post","type-post","status-publish","format-standard","hentry","category-sql"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/1743","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=1743"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/1743\/revisions"}],"predecessor-version":[{"id":1744,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/1743\/revisions\/1744"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=1743"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=1743"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=1743"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}