{"id":2869,"date":"2021-01-06T12:59:49","date_gmt":"2021-01-06T04:59:49","guid":{"rendered":"https:\/\/www.gbase8.cn\/?p=2869"},"modified":"2021-01-10T15:33:25","modified_gmt":"2021-01-10T07:33:25","slug":"gbase-8a%e5%a4%9a%e4%b8%aa%e5%ad%97%e7%ac%a6%e4%b8%b2%e6%8b%bc%e6%8e%a5%e4%b8%80%e8%b5%b7%e7%9a%84%e5%87%bd%e6%95%b0concat%e8%af%ad%e6%b3%95%e5%92%8c%e7%94%a8%e4%be%8b","status":"publish","type":"post","link":"https:\/\/www.gbase8.cn\/en\/2869","title":{"rendered":"\u5357\u5927\u901a\u7528GBase 8a\u591a\u4e2a\u5b57\u7b26\u4e32\u62fc\u63a5\u4e00\u8d77\u7684\u51fd\u6570concat,concat_ws\u8bed\u6cd5\u548c\u7528\u4f8b"},"content":{"rendered":"\n<p>GBase 8a\u6570\u636e\u5e93\u96c6\u7fa4\u63d0\u4f9b\u4e862\u79cd\u5b57\u7b26\u4e32\u62fc\u63a5\u7684\u65b9\u6cd5\uff0c\u4e00\u4e2a\u662f\u53cc\u7ad6\u7ebf\u7684\u7b26\u53f7\uff0c\u53e6\u4e00\u4e2a\u662fconcat\u51fd\u6570\u548cconcat_ws\u6307\u5b9a\u5206\u9694\u7b26\u7684\u51fd\u6570\uff0c\u672c\u6587\u4ecb\u7ecd2\u79cd\u65b9\u6cd5\u7684\u4f7f\u7528\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\">\u76ee\u5f55\u5bfc\u822a<\/p>\n<label for=\"ez-toc-cssicon-toggle-item-6a2b24dc8098c\" 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-6a2b24dc8098c\"  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\/2869\/#Concat\" >Concat<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.gbase8.cn\/en\/2869\/#%E8%AF%AD%E6%B3%95\" >\u8bed\u6cd5<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.gbase8.cn\/en\/2869\/#%E8%AF%B4%E6%98%8E\" >\u8bf4\u660e<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.gbase8.cn\/en\/2869\/#%E7%94%A8%E4%BE%8B\" >\u7528\u4f8b<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.gbase8.cn\/en\/2869\/#%E5%85%A8%E9%83%A8%E6%98%AF%E5%AD%97%E7%AC%A6%E4%B8%B2\" >\u5168\u90e8\u662f\u5b57\u7b26\u4e32<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.gbase8.cn\/en\/2869\/#%E5%B8%A6null%E5%8F%82%E6%95%B0%EF%BC%8C%E7%BB%93%E6%9E%9C%E4%B8%BAnull\" >\u5e26null\u53c2\u6570\uff0c\u7ed3\u679c\u4e3anull.<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.gbase8.cn\/en\/2869\/#Concat_WS\" >Concat_WS<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.gbase8.cn\/en\/2869\/#%E8%AF%AD%E6%B3%95-2\" >\u8bed\u6cd5<\/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\/2869\/#%E8%AF%B4%E6%98%8E-2\" >\u8bf4\u660e<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.gbase8.cn\/en\/2869\/#%E6%A0%B7%E4%BE%8B\" >\u6837\u4f8b<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.gbase8.cn\/en\/2869\/#%E6%AD%A3%E5%B8%B8%E8%BF%9E%E6%8E%A5\" >\u6b63\u5e38\u8fde\u63a5<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/www.gbase8.cn\/en\/2869\/#%E6%9C%89NULL%E5%80%BC\" >\u6709NULL\u503c<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/www.gbase8.cn\/en\/2869\/#%E7%A9%BA%E8%BF%9E%E6%8E%A5%E7%AC%A6%E4%BB%A3%E6%9B%BFconcat\" >\u7a7a\u8fde\u63a5\u7b26\u4ee3\u66ffconcat<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/www.gbase8.cn\/en\/2869\/#%E8%BF%9E%E6%8E%A5%E7%AC%A6%E4%B8%BAnull\" >\u8fde\u63a5\u7b26\u4e3anull<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/www.gbase8.cn\/en\/2869\/#%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=\"Concat\"><\/span>Concat<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 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><\/h3>\n\n\n\n<p>CONCAT(str1,str2,\u2026)<br>str1|str2[|str3...]<\/p>\n\n\n\n<h3 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><\/h3>\n\n\n\n<p>\u8fd4\u56de\u7ed3\u679c\u4e3a\u8fde\u63a5\u53c2\u6570\u4ea7\u751f\u7684\u5b57\u7b26\u4e32\u3002\u5982\u6709\u4efb\u4f55\u4e00\u4e2a\u53c2\u6570\u4e3a NULL\uff0c\u5219\u8fd4\u56de\u503c\u4e3aNULL\u3002<\/p>\n\n\n\n<p>\u6ce8\u610f\uff1a\u63a8\u8350\u7528concat\u65b9\u5f0f\uff0c\u4ee3\u7801\u66f4\u6e05\u6670\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E7%94%A8%E4%BE%8B\"><\/span>\u7528\u4f8b<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E5%85%A8%E9%83%A8%E6%98%AF%E5%AD%97%E7%AC%A6%E4%B8%B2\"><\/span>\u5168\u90e8\u662f\u5b57\u7b26\u4e32<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase&gt; select 'a'||'b'||'c';\n+---------------+\n| 'a'||'b'||'c' |\n+---------------+\n| abc           |\n+---------------+\n1 row in set (Elapsed: 00:00:00.00)\n\ngbase&gt; select concat('a','b','c');\n+---------------------+\n| concat('a','b','c') |\n+---------------------+\n| abc                 |\n+---------------------+\n1 row in set (Elapsed: 00:00:00.00)\n<\/code><\/pre>\n\n\n\n<p>\u7b2c\u4e00\u4e2a\u53c2\u6570\u4e3a\u6570\u5b57\u6216\u8005\u65e5\u671f\uff0c\u7ed3\u679c\u662f\u53c2\u6570\u5148\u8f6c\u6210\u5b57\u7b26\u4e32\uff0c\u518d\u62fc\u63a5\u3002\u7ed3\u679c\u7b26\u5408\u9884\u671f\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase&gt; select 1||'a'||'b'||'c';\n+------------------+\n| 1||'a'||'b'||'c' |\n+------------------+\n| 1abc             |\n+------------------+\n1 row in set (Elapsed: 00:00:00.00)\n\ngbase&gt; select concat(1,'a','b','c');\n+-----------------------+\n| concat(1,'a','b','c') |\n+-----------------------+\n| 1abc                  |\n+-----------------------+\n1 row in set (Elapsed: 00:00:00.00)\n\n<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E5%B8%A6null%E5%8F%82%E6%95%B0%EF%BC%8C%E7%BB%93%E6%9E%9C%E4%B8%BAnull\"><\/span>\u5e26null\u53c2\u6570\uff0c\u7ed3\u679c\u4e3anull.<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>\u6240\u4ee5\u5728\u62fc\u63a5\u524d\uff0c\u8981\u786e\u8ba4\u53c2\u6570\u662f\u5426\u4e3anull,\u5fc5\u8981\u65f6\u7528ifnull, nvl\u7b49\u51fd\u6570\u5904\u7406\u3002\u8be6\u60c5\u770b\u53c2\u8003\u8d44\u6599\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase&gt; select 1||'a'||'b'||null||'c';\n+------------------------+\n| 1||'a'||'b'||null||'c' |\n+------------------------+\n| NULL                   |\n+------------------------+\n1 row in set (Elapsed: 00:00:00.00)\n\ngbase&gt; select concat(1,'a','b',null,'c');\n+----------------------------+\n| concat(1,'a','b',null,'c') |\n+----------------------------+\n| NULL                       |\n+----------------------------+\n1 row in set (Elapsed: 00:00:00.00)\n\n<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Concat_WS\"><\/span>Concat_WS<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E8%AF%AD%E6%B3%95-2\"><\/span>\u8bed\u6cd5<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>CONCAT_WS(separator,str1,str2,...)<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E8%AF%B4%E6%98%8E-2\"><\/span>\u8bf4\u660e<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>CONCAT_WS()\u4ee3\u8868 CONCAT With Separator\uff0c\u662f CONCAT()\u7684\u7279\u6b8a\u5f62\u5f0f\u3002\u7b2c\u4e00\u4e2a\u53c2\u6570\u662f\u5176\u5b83\u53c2\u6570\u7684\u5206\u9694\u7b26\u3002<br>\u5206\u9694\u7b26\u7684\u4f4d\u7f6e\u653e\u5728\u8981\u8fde\u63a5\u7684\u4e24\u4e2a\u5b57\u7b26\u4e32\u4e4b\u95f4\u3002\u5206\u9694\u7b26\u53ef\u4ee5\u662f\u4e00\u4e2a\u5b57\u7b26\u4e32\uff0c\u4e5f\u53ef\u4ee5\u662f\u5176\u5b83\u53c2\u6570\u3002<br>\u5982\u679c\u5206\u9694\u7b26\u4e3a NULL\uff0c\u5219\u7ed3\u679c\u4e3a NULL\u3002<br>\u51fd\u6570\u4f1a\u5ffd\u7565\u5206\u9694\u7b26\u540e\u9762\u53c2\u6570\u4e2d\u7684 NULL \u503c\u3002<\/p>\n\n\n\n<h3 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><\/h3>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E6%AD%A3%E5%B8%B8%E8%BF%9E%E6%8E%A5\"><\/span>\u6b63\u5e38\u8fde\u63a5<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase> select concat_ws('_','A','B','C');\r\n+----------------------------+\r\n| concat_ws('_','A','B','C') |\r\n+----------------------------+\r\n| A_B_C                      |\r\n+----------------------------+\r\n1 row in set (Elapsed: 00:00:00.00)\r\n<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E6%9C%89NULL%E5%80%BC\"><\/span>\u6709NULL\u503c<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>null\u503c\u88ab\u5ffd\u7565\u4e86\uff0c\u4e0d\u50cfconcat\u90a3\u6837\u6709\u4efb\u4f55\u4e00\u4e2a\u503c\u4e3anull\u5219\u7ed3\u679c\u503c\u4e3anull\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase> select concat_ws('_','A',null,'C');\r\n+-----------------------------+\r\n| concat_ws('_','A',null,'C') |\r\n+-----------------------------+\r\n| A_C                         |\r\n+-----------------------------+\r\n1 row in set (Elapsed: 00:00:00.00)\r\n<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E7%A9%BA%E8%BF%9E%E6%8E%A5%E7%AC%A6%E4%BB%A3%E6%9B%BFconcat\"><\/span>\u7a7a\u8fde\u63a5\u7b26\u4ee3\u66ffconcat<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>\u5f53\u5206\u9694\u7b26\u4e3a\u7a7a\u5b57\u7b26\u4e32\u65f6\uff0c\u7b49\u540c\u4e8econcat\u51fd\u6570\uff0c\u4f46\u4e0d\u62c5\u5fc3null\u95ee\u9898\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase> select concat_ws('','A',null,'C');\r\n+----------------------------+\r\n| concat_ws('','A',null,'C') |\r\n+----------------------------+\r\n| AC                         |\r\n+----------------------------+\r\n1 row in set (Elapsed: 00:00:00.00)\r\n<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"%E8%BF%9E%E6%8E%A5%E7%AC%A6%E4%B8%BAnull\"><\/span>\u8fde\u63a5\u7b26\u4e3anull<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<p>\u7ed3\u679c\u4e3aNull<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>gbase> select concat_ws(null,'A','B','C');\r\n+-----------------------------+\r\n| concat_ws(null,'A','B','C') |\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<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<p><a href=\"https:\/\/www.gbase8.cn\/2529\">GBase 8a\u5bf9null\u76f8\u5173\u51fd\u6570nvl\uff0cifnull,nullif\u7b49<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5357\u5927\u901a\u7528GBase 8a\u6570\u636e\u5e93\u96c6\u7fa4\u63d0\u4f9b\u4e862\u79cd\u5b57\u7b26\u4e32\u62fc\u63a5\u7684\u65b9\u6cd5\uff0c\u4e00\u4e2a\u662f\u53cc\u7ad6\u7ebf\u7684\u7b26\u53f7\uff0c\u53e6\u4e00\u4e2a\u662fconcat\u51fd\u6570\u548cconcat_ws\u6307\u5b9a\u5206\u9694\u7b26\u7684\u51fd\u6570\uff0c\u672c\u6587\u4ecb\u7ecd2\u79cd\u65b9\u6cd5\u7684\u4f7f\u7528\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-2869","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\/2869","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=2869"}],"version-history":[{"count":5,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/2869\/revisions"}],"predecessor-version":[{"id":3257,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/posts\/2869\/revisions\/3257"}],"wp:attachment":[{"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/media?parent=2869"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/categories?post=2869"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gbase8.cn\/en\/wp-json\/wp\/v2\/tags?post=2869"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}