{"id":2995,"date":"2021-01-07T10:21:05","date_gmt":"2021-01-07T02:21:05","guid":{"rendered":"https:\/\/www.gbase8.cn\/?p=2995"},"modified":"2021-01-07T10:21:06","modified_gmt":"2021-01-07T02:21:06","slug":"gbase-8a%e5%ad%97%e7%ac%a6%e4%b8%b2%e5%ad%97%e8%8a%82%e9%95%bf%e5%ba%a6%e5%87%bd%e6%95%b0length%e7%9a%84%e7%94%a8%e6%b3%95%e5%92%8c%e4%be%8b%e5%ad%90","status":"publish","type":"post","link":"https:\/\/www.gbase8.cn\/en\/2995","title":{"rendered":"\u5357\u5927\u901a\u7528GBase 8a\u5b57\u7b26\u4e32\u5b57\u8282\u957f\u5ea6\u51fd\u6570LENGTH\u7684\u7528\u6cd5\u548c\u4f8b\u5b50"},"content":{"rendered":"<p>\u672c\u6587\u4ecb\u7ecdGBase 8a\u6570\u636e\u5e93\u96c6\u7fa4\uff0c\u8ba1\u7b97\u5b57\u7b26\u4e32\u3010\u5b57\u8282\u3011\u957f\u5ea6\u7684\u51fd\u6570length\u7684\u8bed\u6cd5\u3001\u8bf4\u660e\u548c\u4f7f\u7528\u6837\u4f8b\u3002\u8bf7\u6ce8\u610f\u5176\u4e0e\u3010\u5b57\u7b26\u3011\u957f\u5ea6\u7684\u51fd\u6570char_length\u7684\u533a\u522b\u3002<\/p>\n\n\n\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_84 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Directory Navigation<\/p>\n<label for=\"ez-toc-cssicon-toggle-item-6a2ad3e7cc9b0\" class=\"ez-toc-cssicon-toggle-label\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewbox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewbox=\"0 0 24 24\" version=\"1.2\" baseprofile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/label><input type=\"checkbox\"  id=\"ez-toc-cssicon-toggle-item-6a2ad3e7cc9b0\"  aria-label=\"Toggle\" \/><nav><ul class='ez-toc-list ez-toc-list-level-1' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.gbase8.cn\/en\/2995\/#%E8%AF%AD%E6%B3%95\" >\u8bed\u6cd5<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.gbase8.cn\/en\/2995\/#%E8%AF%B4%E6%98%8E\" >\u8bf4\u660e<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.gbase8.cn\/en\/2995\/#%E6%A0%B7%E4%BE%8B\" >\u6837\u4f8b<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.gbase8.cn\/en\/2995\/#ASCII%E5%AD%97%E7%AC%A6%E5%8F%82%E6%95%B0\" >ASCII\u5b57\u7b26\u53c2\u6570<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.gbase8.cn\/en\/2995\/#%E6%B1%89%E5%AD%97%E5%8F%82%E6%95%B0\" >\u6c49\u5b57\u53c2\u6570<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.gbase8.cn\/en\/2995\/#NULL%E5%80%BC%E5%8F%82%E6%95%B0\" >NULL\u503c\u53c2\u6570<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.gbase8.cn\/en\/2995\/#%E6%99%AE%E9%80%9A%E6%95%B0%E5%AD%97\" >\u666e\u901a\u6570\u5b57<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.gbase8.cn\/en\/2995\/#%E7%A7%91%E5%AD%A6%E8%AE%A1%E6%95%B0%E6%B3%95%E7%9A%84%E6%95%B0%E5%AD%97\" >\u79d1\u5b66\u8ba1\u6570\u6cd5\u7684\u6570\u5b57<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.gbase8.cn\/en\/2995\/#%E5%8F%82%E8%80%83\" >\u53c2\u8003<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E8%AF%AD%E6%B3%95\"><\/span>\u8bed\u6cd5<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<pre class=\"wp-block-code\"><code>LENGTH(str)\n<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E8%AF%B4%E6%98%8E\"><\/span>\u8bf4\u660e<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>\u8fd4\u56de\u5b57\u7b26\u4e32 str \u7684\u957f\u5ea6\uff0c\u4ee5\u5b57\u8282\u8fdb\u884c\u8ba1\u7b97\u3002\u591a\u5b57\u8282\u7684\u5b57\u7b26\uff0c\u6bd4\u5982\u6c49\u5b57\uff0c\u957f\u5ea6\u4f1a\u6839\u636e\u5b9e\u9645\u5360\u7528\u5b57\u8282\u8ba1\u7b97\u3002<\/p>\n\n\n\n<p>\u5982\u679c\u53c2\u6570\u4e3anull,\u5219\u8fd4\u56denull\u3002<br>\u5982\u53c2\u6570\u4e3a\u6570\u5b57\uff0c\u4f1a\u5148\u8f6c\u6210\u5b57\u7b26\uff0c\u79d1\u5b66\u8ba1\u6570\u6cd5\u4f1a\u5148\u5c55\u5f00\uff0c\u5982\u6709\u5c0f\u6570\u70b9\u4f1a\u5360\u7528\u4e00\u4e2a\u5b57\u7b26\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E6%A0%B7%E4%BE%8B\"><\/span>\u6837\u4f8b<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"ASCII%E5%AD%97%E7%AC%A6%E5%8F%82%E6%95%B0\"><\/span>ASCII\u5b57\u7b26\u53c2\u6570<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase> select length('abcdef');\r\n+------------------+\r\n| length('abcdef') |\r\n+------------------+\r\n|                6 |\r\n+------------------+\r\n1 row in set (Elapsed: 00:00:00.00)\r\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E6%B1%89%E5%AD%97%E5%8F%82%E6%95%B0\"><\/span>\u6c49\u5b57\u53c2\u6570<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>utf8\u7f16\u7801\u7684\u6bcf\u4e2a\u6c49\u5b57\u5360\u75283\u4e2a\u5b57\u8282\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase> select length('\u5357\u5927\u901a\u7528');\r\n+------------------------+\r\n| length('\u5357\u5927\u901a\u7528')     |\r\n+------------------------+\r\n|                     12 |\r\n+------------------------+\r\n1 row in set (Elapsed: 00:00:00.00)\r\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"NULL%E5%80%BC%E5%8F%82%E6%95%B0\"><\/span>NULL\u503c\u53c2\u6570<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>\u8fd4\u56denull<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase> select length(null);\r\n+--------------+\r\n| length(null) |\r\n+--------------+\r\n|         NULL |\r\n+--------------+\r\n1 row in set (Elapsed: 00:00:00.00)\r\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E6%99%AE%E9%80%9A%E6%95%B0%E5%AD%97\"><\/span>\u666e\u901a\u6570\u5b57<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>\u5148\u8f6c\u6210\u5b57\u7b26\u7c7b\u578b\uff0c\u5982\u6709\u5c0f\u6570\u70b9\u4e5f\u5360\u7528\u4e00\u4e2a\u5b57\u8282\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase> select length(123456);\r\n+----------------+\r\n| length(123456) |\r\n+----------------+\r\n|              6 |\r\n+----------------+\r\n1 row in set (Elapsed: 00:00:00.00)\r\n\r\ngbase> select length(123.456);\r\n+-----------------+\r\n| length(123.456) |\r\n+-----------------+\r\n|               7 |\r\n+-----------------+\r\n1 row in set (Elapsed: 00:00:00.01)\r\n\r\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E7%A7%91%E5%AD%A6%E8%AE%A1%E6%95%B0%E6%B3%95%E7%9A%84%E6%95%B0%E5%AD%97\"><\/span>\u79d1\u5b66\u8ba1\u6570\u6cd5\u7684\u6570\u5b57<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>\u9009\u5c55\u5f00\u6210\u6b63\u5e38\u7684\u6570\u5b57\uff0c\u518d\u8f6c\u5316\u6210\u5b57\u7b26\u4e32\u3002\u540c\u6837\u5982\u679c\u6709\u5c0f\u6570\u70b9\uff0c\u4e5f\u5360\u7528\u4e00\u4e2a\u5b57\u8282\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase> select length(1.23456E4);\r\n+-------------------+\r\n| length(1.23456E4) |\r\n+-------------------+\r\n|                 7 |\r\n+-------------------+\r\n1 row in set (Elapsed: 00:00:00.00)\r\n\r\ngbase> select length(1.23456E5);\r\n+-------------------+\r\n| length(1.23456E5) |\r\n+-------------------+\r\n|                 6 |\r\n+-------------------+\r\n1 row in set (Elapsed: 00:00:00.00)\r\n\r\ngbase> select length(1.23456E6);\r\n+-------------------+\r\n| length(1.23456E6) |\r\n+-------------------+\r\n|                 7 |\r\n+-------------------+\r\n1 row in set (Elapsed: 00:00:00.00)\r\n<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E5%8F%82%E8%80%83\"><\/span>\u53c2\u8003<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<figure class=\"wp-block-embed is-type-wp-embed is-provider-\u8001\u7d2b\u7af9\u7684\u5bb6 wp-block-embed-\u8001\u7d2b\u7af9\u7684\u5bb6\"><div class=\"wp-block-embed__wrapper\">\n<blockquote class=\"wp-embedded-content\" data-secret=\"ZxXux8U0D5\"><a href=\"https:\/\/www.gbase8.cn\/en\/2993\/\">GBase 8a\u5b57\u7b26\u4e32\u5b57\u7b26\u957f\u5ea6\u51fd\u6570CHAR_LENGTH\u3001CHARACTER_LENGTH\u7684\u7528\u6cd5\u548c\u4f8b\u5b50<\/a><\/blockquote><iframe loading=\"lazy\" class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; clip: rect(1px, 1px, 1px, 1px);\" title=\"\u300aGBase 8a\u5b57\u7b26\u4e32\u5b57\u7b26\u957f\u5ea6\u51fd\u6570CHAR_LENGTH\u3001CHARACTER_LENGTH\u7684\u7528\u6cd5\u548c\u4f8b\u5b50\u300b\u2014\u8001\u7d2b\u7af9\u7684\u5bb6\" src=\"https:\/\/www.gbase8.cn\/2993\/embed#?secret=ZxXux8U0D5\" data-secret=\"ZxXux8U0D5\" width=\"600\" height=\"338\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe>\n<\/div><\/figure>","protected":false},"excerpt":{"rendered":"<p>\u672c\u6587\u4ecb\u7ecdGBase 8a\u6570\u636e\u5e93\u96c6\u7fa4\uff0c\u8ba1\u7b97\u5b57\u7b26\u4e32\u3010\u5b57\u8282\u3011\u957f\u5ea6\u7684\u51fd\u6570length\u7684\u8bed\u6cd5\u3001\u8bf4\u660e\u548c\u4f7f\u7528\u6837\u4f8b\u3002\u8bf7\u6ce8\u610f\u5176\u4e0e\u3010\u5b57\u7b26\u3011\u957f\u5ea6\u7684\u51fd\u6570char_length\u7684\u533a\u522b\u3002<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[36],"class_list":["post-2995","post","type-post","status-publish","format-standard","hentry","category-gbase8a","tag-36"],"_links":{"self":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/2995","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/comments?post=2995"}],"version-history":[{"count":5,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/2995\/revisions"}],"predecessor-version":[{"id":3016,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/2995\/revisions\/3016"}],"wp:attachment":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/media?parent=2995"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/categories?post=2995"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/tags?post=2995"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}