{"id":735,"date":"2019-12-20T19:17:53","date_gmt":"2019-12-20T11:17:53","guid":{"rendered":"http:\/\/prayerlaputa.com\/?p=735"},"modified":"2019-12-20T19:19:11","modified_gmt":"2019-12-20T11:19:11","slug":"mysql-%e5%b8%b8%e7%94%a8%e5%87%bd%e6%95%b0%e6%95%b4%e7%90%86","status":"publish","type":"post","link":"http:\/\/prayerlaputa.com\/?p=735","title":{"rendered":"mysql \u5e38\u7528\u51fd\u6570\u6574\u7406"},"content":{"rendered":"<h1 id=\"mysql-%E5%B8%B8%E7%94%A8%E5%87%BD%E6%95%B0%E6%95%B4%E7%90%86\" class=\"mume-header\">mysql \u5e38\u7528\u51fd\u6570\u6574\u7406<\/h1>\n<ul>\n<li><a href=\"file:\/\/\/D:\/GitRepository\/JavaKnowledgeTree\/SQL\/mysql%E4%B8%AD%E7%9A%84%E5%B8%B8%E7%94%A8%E5%87%BD%E6%95%B0.md#mysql-%E5%B8%B8%E7%94%A8%E5%87%BD%E6%95%B0%E6%95%B4%E7%90%86\">mysql \u5e38\u7528\u51fd\u6570\u6574\u7406<\/a>\n<ul>\n<li><a href=\"file:\/\/\/D:\/GitRepository\/JavaKnowledgeTree\/SQL\/mysql%E4%B8%AD%E7%9A%84%E5%B8%B8%E7%94%A8%E5%87%BD%E6%95%B0.md#%E5%AD%97%E7%AC%A6%E4%B8%B2%E6%93%8D%E4%BD%9C\">\u5b57\u7b26\u4e32\u64cd\u4f5c<\/a>\n<ul>\n<li><a href=\"file:\/\/\/D:\/GitRepository\/JavaKnowledgeTree\/SQL\/mysql%E4%B8%AD%E7%9A%84%E5%B8%B8%E7%94%A8%E5%87%BD%E6%95%B0.md#%E5%AD%97%E7%AC%A6%E4%B8%B2%E6%8B%BC%E6%8E%A5-concat\">\u5b57\u7b26\u4e32\u62fc\u63a5 concat<\/a><\/li>\n<li><a href=\"file:\/\/\/D:\/GitRepository\/JavaKnowledgeTree\/SQL\/mysql%E4%B8%AD%E7%9A%84%E5%B8%B8%E7%94%A8%E5%87%BD%E6%95%B0.md#%E5%8E%BB%E6%8E%89%E6%97%A0%E7%94%A8%E7%A9%BA%E6%A0%BC-trim\">\u53bb\u6389\u65e0\u7528\u7a7a\u683c trim<\/a><\/li>\n<li><a href=\"file:\/\/\/D:\/GitRepository\/JavaKnowledgeTree\/SQL\/mysql%E4%B8%AD%E7%9A%84%E5%B8%B8%E7%94%A8%E5%87%BD%E6%95%B0.md#%E6%88%AA%E5%8F%96%E5%AD%97%E7%AC%A6%E4%B8%B2\">\u622a\u53d6\u5b57\u7b26\u4e32<\/a>\n<ul>\n<li><a href=\"file:\/\/\/D:\/GitRepository\/JavaKnowledgeTree\/SQL\/mysql%E4%B8%AD%E7%9A%84%E5%B8%B8%E7%94%A8%E5%87%BD%E6%95%B0.md#%E8%8E%B7%E5%8F%96%E5%89%8D%E7%BC%80-left\">\u83b7\u53d6\u524d\u7f00 left<\/a><\/li>\n<li><a href=\"file:\/\/\/D:\/GitRepository\/JavaKnowledgeTree\/SQL\/mysql%E4%B8%AD%E7%9A%84%E5%B8%B8%E7%94%A8%E5%87%BD%E6%95%B0.md#%E8%8E%B7%E5%8F%96%E5%90%8E%E7%BC%80-right\">\u83b7\u53d6\u540e\u7f00 right<\/a><\/li>\n<li><a href=\"file:\/\/\/D:\/GitRepository\/JavaKnowledgeTree\/SQL\/mysql%E4%B8%AD%E7%9A%84%E5%B8%B8%E7%94%A8%E5%87%BD%E6%95%B0.md#%E6%88%AA%E5%8F%96%E5%AD%97%E7%AC%A6%E4%B8%B2-substring_index\">\u622a\u53d6\u5b57\u7b26\u4e32 substring_index<\/a><\/li>\n<li><a href=\"file:\/\/\/D:\/GitRepository\/JavaKnowledgeTree\/SQL\/mysql%E4%B8%AD%E7%9A%84%E5%B8%B8%E7%94%A8%E5%87%BD%E6%95%B0.md#%E6%88%AA%E5%8F%96%E5%AD%97%E7%AC%A6%E4%B8%B2-substring\">\u622a\u53d6\u5b57\u7b26\u4e32 substring<\/a><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<li><a href=\"file:\/\/\/D:\/GitRepository\/JavaKnowledgeTree\/SQL\/mysql%E4%B8%AD%E7%9A%84%E5%B8%B8%E7%94%A8%E5%87%BD%E6%95%B0.md#%E5%8F%82%E8%80%83%E8%B5%84%E6%96%99\">\u53c2\u8003\u8d44\u6599<\/a><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2 id=\"%E5%AD%97%E7%AC%A6%E4%B8%B2%E6%93%8D%E4%BD%9C\" class=\"mume-header\">\u5b57\u7b26\u4e32\u64cd\u4f5c<\/h2>\n<p><!--more--><\/p>\n<h3 id=\"%E5%AD%97%E7%AC%A6%E4%B8%B2%E6%8B%BC%E6%8E%A5-concat\" class=\"mume-header\">\u5b57\u7b26\u4e32\u62fc\u63a5 concat<\/h3>\n<pre class=\"language-\" data-role=\"codeBlock\" data-info=\"\"><code>select id, name, concat('-', name, '-') from t_student;\r\n<\/code><\/pre>\n<h3 id=\"%E5%8E%BB%E6%8E%89%E6%97%A0%E7%94%A8%E7%A9%BA%E6%A0%BC-trim\" class=\"mume-header\">\u53bb\u6389\u65e0\u7528\u7a7a\u683c trim<\/h3>\n<pre class=\"language-\" data-role=\"codeBlock\" data-info=\"\"><code>select id, name, trim(name) from t_student\r\n<\/code><\/pre>\n<h3 id=\"%E6%88%AA%E5%8F%96%E5%AD%97%E7%AC%A6%E4%B8%B2\" class=\"mume-header\">\u622a\u53d6\u5b57\u7b26\u4e32<\/h3>\n<h4 id=\"%E8%8E%B7%E5%8F%96%E5%89%8D%E7%BC%80-left\" class=\"mume-header\">\u83b7\u53d6\u524d\u7f00 left<\/h4>\n<h4 id=\"%E8%8E%B7%E5%8F%96%E5%90%8E%E7%BC%80-right\" class=\"mume-header\">\u83b7\u53d6\u540e\u7f00 right<\/h4>\n<h4 id=\"%E6%88%AA%E5%8F%96%E5%AD%97%E7%AC%A6%E4%B8%B2-substring_index\" class=\"mume-header\">\u622a\u53d6\u5b57\u7b26\u4e32 substring_index<\/h4>\n<p>substring_index(str,delim,count)<br \/>\n\u53c2\u6570\u4f9d\u6b21\u662f\uff1a\u8981\u5206\u9694\u622a\u53d6\u7684\u5b57\u7b26\u4e32\uff08\u5982\uff1a\u201daaa_bbb_ccc\u201d\uff09\u3001\u5206\u9694\u7b26\uff08\u5982\uff1a\u201c_\u201d\uff09\u3001\u4f4d\u7f6e\uff08\u8868\u793a\u7b2c\u51e0\u4e2a\u5206\u9694\u7b26\u5904\uff0c\u5982\uff1a\u201c1\u201d\uff09\u3002<br \/>\ncount\u4e3a\u6b63\u6570\uff0c\u90a3\u4e48\u5c31\u662f\u4ece\u5de6\u8fb9\u5f00\u59cb\u6570\uff0c\u51fd\u6570\u8fd4\u56de\u7b2ccount\u4e2a\u5206\u9694\u7b26\u7684\u5de6\u4fa7\u7684\u5b57\u7b26\u4e32;<br \/>\ncount\u4e3a\u8d1f\u6570\uff0c\u90a3\u4e48\u5c31\u662f\u4ece\u53f3\u8fb9\u5f00\u59cb\u6570\uff0c\u51fd\u6570\u8fd4\u56de\u7b2ccount\u4e2a\u5206\u9694\u7b26\u53f3\u8fb9\u7684\u6240\u6709\u5185\u5bb9;<br \/>\ncount\u53ef\u4ee5\u4e3a0\uff0c\u8fd4\u56de\u4e3a\u7a7a\u3002<\/p>\n<p>\u4f8b\u5b50\uff1a<\/p>\n<pre class=\"language-\" data-role=\"codeBlock\" data-info=\"\"><code>substring_index(\"aaa_bbb_ccc\",\"_\",1) #\u8fd4\u56de\u4e3a aaa\uff1b\r\nsubstring_index(\"aaa_bbb_ccc\",\"_\",2) #\u8fd4\u56de\u4e3a aaa_bbb\uff1b\r\nsubstring_index(substring_index(\"aaa_bbb_ccc\",\"_\",-2),\"_\",1) \u8fd4\u56de\u4e3a bbb\uff1b\r\n<\/code><\/pre>\n<h4 id=\"%E6%88%AA%E5%8F%96%E5%AD%97%E7%AC%A6%E4%B8%B2-substring\" class=\"mume-header\">\u622a\u53d6\u5b57\u7b26\u4e32 substring<\/h4>\n<p>substring(string,position);<br \/>\nsubstring(string FROM position);<\/p>\n<p>\u53c2\u6570\u4f9d\u6b21\u662f\uff1a<\/p>\n<ul>\n<li>string\u53c2\u6570\u662f\u8981\u63d0\u53d6\u5b50\u5b57\u7b26\u4e32\u7684\u5b57\u7b26\u4e32\u3002<\/li>\n<li>position\u53c2\u6570\u662f\u4e00\u4e2a\u6574\u6570\uff0c\u7528\u4e8e\u6307\u5b9a\u5b50\u4e32\u7684\u8d77\u59cb\u5b57\u7b26\uff0cposition\u53ef\u4ee5\u662f\u6b63\u6216\u8d1f\u6574\u6570\u3002<\/li>\n<\/ul>\n<p>\u6ce8\u610f\uff0cSQL\u4e2d\uff0c\u5b57\u7b26\u4e32\u7684\u8d77\u59cb\u5e8f\u53f7\u4ece<strong>1<\/strong>\u5f00\u59cb\u3002<\/p>\n<h2 id=\"%E5%8F%82%E8%80%83%E8%B5%84%E6%96%99\" class=\"mume-header\">\u53c2\u8003\u8d44\u6599<\/h2>\n<ul>\n<li><a href=\"https:\/\/blog.csdn.net\/qq_34579060\/article\/details\/80283575\">MySQL substring()\u51fd\u6570<\/a><\/li>\n<li><a href=\"https:\/\/baijiahao.baidu.com\/s?id=1616911854187546637&amp;wfr=spider&amp;for=pc\">MySQL\u5b57\u7b26\u4e32\u622a\u53d6\u548c\u622a\u53d6\u5b57\u7b26\u8fdb\u884c\u67e5\u8be2<\/a><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>mysql \u5e38\u7528\u51fd\u6570\u6574\u7406 mysql \u5e38\u7528\u51fd\u6570\u6574\u7406 \u5b57\u7b26\u4e32\u64cd\u4f5c \u5b57\u7b26\u4e32\u62fc\u63a5 concat \u53bb\u6389\u65e0\u7528\u7a7a\u683c tri <a href='http:\/\/prayerlaputa.com\/?p=735' class='excerpt-more'>[&#8230;]<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0},"categories":[63],"tags":[64],"_links":{"self":[{"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=\/wp\/v2\/posts\/735"}],"collection":[{"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=735"}],"version-history":[{"count":2,"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=\/wp\/v2\/posts\/735\/revisions"}],"predecessor-version":[{"id":737,"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=\/wp\/v2\/posts\/735\/revisions\/737"}],"wp:attachment":[{"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=735"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=735"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/prayerlaputa.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=735"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}