{"id":2993,"date":"2021-01-07T10:02:19","date_gmt":"2021-01-07T02:02:19","guid":{"rendered":"https:\/\/www.gbase8.cn\/?p=2993"},"modified":"2021-01-07T10:21:29","modified_gmt":"2021-01-07T02:21:29","slug":"gbase-8a%e5%ad%97%e7%ac%a6%e4%b8%b2%e5%ad%97%e7%ac%a6%e9%95%bf%e5%ba%a6%e5%87%bd%e6%95%b0char_length%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\/2993","title":{"rendered":"\u5357\u5927\u901a\u7528GBase 8a\u5b57\u7b26\u4e32\u5b57\u7b26\u957f\u5ea6\u51fd\u6570CHAR_LENGTH\u3001CHARACTER_LENGTH\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\u7b26\u3011\u957f\u5ea6\u7684\u51fd\u6570char_length\u7684\u7528\u6cd5\u548c\u4f8b\u5b50\u3002\u8bf7\u6ce8\u610f\u533a\u5206\u5176\u4e0elength\uff0c\u5b57\u7b26\u4e32\u3010\u5b57\u8282\u3011\u957f\u5ea6\u7684\u5dee\u5f02\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-6a2aae050ecf1\" 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-6a2aae050ecf1\"  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\/2993\/#%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\/2993\/#%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\/2993\/#%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\/2993\/#ASCII%E5%AD%97%E7%AC%A6\" >ASCII\u5b57\u7b26<\/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\/2993\/#%E6%B1%89%E5%AD%97\" >\u6c49\u5b57<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.gbase8.cn\/en\/2993\/#%E4%B8%8Elength%E7%9A%84%E5%B7%AE%E5%88%AB\" >\u4e0elength\u7684\u5dee\u522b<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.gbase8.cn\/en\/2993\/#character_length%E5%92%8Cchar_length%E5%AE%8C%E5%85%A8%E7%9B%B8%E5%90%8C\" >character_length\u548cchar_length\u5b8c\u5168\u76f8\u540c<\/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\/2993\/#NULL%E5%8F%82%E6%95%B0%E8%BF%94%E5%9B%9Enull\" >NULL\u53c2\u6570\u8fd4\u56denull<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.gbase8.cn\/en\/2993\/#%E6%95%B0%E5%AD%97%E5%8F%82%E6%95%B0\" >\u6570\u5b57\u53c2\u6570<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.gbase8.cn\/en\/2993\/#%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>CHAR_LENGTH(str)\nCHARACTER_LENGTH(str)<\/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\u5b57\u7b26\u957f\u5ea6\uff0c\u4ee5\u5b57\u7b26\u4e2a\u6570\u4e3a\u5355\u4f4d\u3002CHAR_LENGTH\u548cCHARACTER_LENGTH\u662f\u5b8c\u5168\u4e00\u6837\u7684\uff0c\u522b\u540d\u3002<\/p>\n\n\n\n<p>\u53c2\u6570\u4e3aNULL\u5219\u8fd4\u56denull\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\"><\/span>ASCII\u5b57\u7b26<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase&gt; select char_length('123456');\n+-----------------------+\n| char_length('123456') |\n+-----------------------+\n|                     6 |\n+-----------------------+\n1 row in set (Elapsed: 00:00:00.00)\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E6%B1%89%E5%AD%97\"><\/span>\u6c49\u5b57<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>\u5b57\u7b26\uff0c\u662f\u4e0d\u8003\u8651\u7f16\u7801\u7684\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase&gt; select char_length('\u5357\u5927\u901a\u7528');\n+-----------------------------+\n| char_length('\u5357\u5927\u901a\u7528')     |\n+-----------------------------+\n|                           4 |\n+-----------------------------+\n1 row in set (Elapsed: 00:00:00.00)\n<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E4%B8%8Elength%E7%9A%84%E5%B7%AE%E5%88%AB\"><\/span>\u4e0elength\u7684\u5dee\u522b<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>\u5bf9\u4e8e\u591a\u5b57\u8282\u7f16\u7801\u7684\u5b57\u7b26\uff0clength\u8fd4\u56de\u7684\u662f\u5b57\u8282\u957f\u5ea6\uff0c\u548c\u7f16\u7801\u957f\u5ea6\u6709\u5173\uff0cchar_length\u662f\u5b57\u7b26\u957f\u5ea6\uff0c\u4e0e\u7f16\u7801\u65e0\u5173\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase&gt; select length('\u5357\u5927\u901a\u7528');\n+------------------------+\n| length('\u5357\u5927\u901a\u7528')     |\n+------------------------+\ngbase&gt; select bit_length('\u5357\u5927\u901a\u7528'),length('\u5357\u5927\u901a\u7528'),char_length('\u5357\u5927\u901a\u7528');\n+----------------------------+------------------------+-----------------------------+\n| bit_length('\u5357\u5927\u901a\u7528')     | length('\u5357\u5927\u901a\u7528')     | char_length('\u5357\u5927\u901a\u7528')     |\n+----------------------------+------------------------+-----------------------------+\n|                         96 |                     12 |                           4 |\n+----------------------------+------------------------+-----------------------------+\n1 row in set (Elapsed: 00:00:00.00)\n<\/code><\/pre>\n\n\n\n<p>\u53ef\u4ee5\u770b\u5230\u6bcf\u4e2aUTF8\u7f16\u7801\u6c49\u5b57\uff0c\u5360\u75283\u4e2a\u5b57\u8282\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"character_length%E5%92%8Cchar_length%E5%AE%8C%E5%85%A8%E7%9B%B8%E5%90%8C\"><\/span>character_length\u548cchar_length\u5b8c\u5168\u76f8\u540c<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase&gt; select char_length('\u5357\u5927\u901a\u7528'),character_length('\u5357\u5927\u901a\u7528');\n+-----------------------------+----------------------------------+\n| char_length('\u5357\u5927\u901a\u7528')     | character_length('\u5357\u5927\u901a\u7528')     |\n+-----------------------------+----------------------------------+\n|                           4 |                                4 |\n+-----------------------------+----------------------------------+\n1 row in set (Elapsed: 00:00:00.00)\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"NULL%E5%8F%82%E6%95%B0%E8%BF%94%E5%9B%9Enull\"><\/span>NULL\u53c2\u6570\u8fd4\u56denull<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase&gt; select char_length(null);\n+-------------------+\n| char_length(null) |\n+-------------------+\n|              NULL |\n+-------------------+\n1 row in set (Elapsed: 00:00:00.00)\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E6%95%B0%E5%AD%97%E5%8F%82%E6%95%B0\"><\/span>\u6570\u5b57\u53c2\u6570<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>\u5148\u8f6c\u6210\u5b57\u7b26\u4e32\u518d\u8ba1\u7b97\u3002\u5305\u62ec\u79d1\u5b66\u8ba1\u6570\u6cd5\u4f1a\u5148\u5c55\u5f00\u3002\u5982\u6709\u5c0f\u6570\u70b9\u4e5f\u7b97\u4e00\u4e2a\u5b57\u7b26\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase&gt; select char_length(1234567890);\n+-------------------------+\n| char_length(1234567890) |\n+-------------------------+\n|                      10 |\n+-------------------------+\n1 row in set (Elapsed: 00:00:00.00)\ngbase&gt; select char_length(1.23E4);\n+---------------------+\n| char_length(1.23E4) |\n+---------------------+\n|                   5 |\n+---------------------+\n1 row in set (Elapsed: 00:00:00.01)\n\ngbase&gt; select char_length(1.2345E4);\n+-----------------------+\n| char_length(1.2345E4) |\n+-----------------------+\n|                     5 |\n+-----------------------+\n1 row in set (Elapsed: 00:00:00.00)\n\ngbase&gt; select char_length(1.23456E4);\n+------------------------+\n| char_length(1.23456E4) |\n+------------------------+\n|                      7 |\n+------------------------+\n1 row in set (Elapsed: 00:00:00.00)\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=\"IwYJ45ipl7\"><a href=\"https:\/\/www.gbase8.cn\/en\/2995\/\">GBase 8a\u5b57\u7b26\u4e32\u5b57\u8282\u957f\u5ea6\u51fd\u6570LENGTH\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\u8282\u957f\u5ea6\u51fd\u6570LENGTH\u7684\u7528\u6cd5\u548c\u4f8b\u5b50\u300b\u2014\u8001\u7d2b\u7af9\u7684\u5bb6\" src=\"https:\/\/www.gbase8.cn\/2995\/embed#?secret=IwYJ45ipl7\" data-secret=\"IwYJ45ipl7\" 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\u7b26\u3011\u957f\u5ea6\u7684\u51fd\u6570char_length\u7684\u7528\u6cd5\u548c\u4f8b\u5b50\u3002\u8bf7\u6ce8\u610f\u533a\u5206\u5176\u4e0elength\uff0c\u5b57\u7b26\u4e32\u3010\u5b57\u8282\u3011\u957f\u5ea6\u7684\u5dee\u5f02\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-2993","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\/2993","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=2993"}],"version-history":[{"count":7,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/2993\/revisions"}],"predecessor-version":[{"id":3017,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/2993\/revisions\/3017"}],"wp:attachment":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/media?parent=2993"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/categories?post=2993"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/tags?post=2993"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}