{"id":131827,"date":"2020-07-05T02:34:30","date_gmt":"2020-07-04T18:34:30","guid":{"rendered":"http:\/\/4563.org\/?p=131827"},"modified":"2020-07-05T02:34:30","modified_gmt":"2020-07-04T18:34:30","slug":"mysql-%e5%b8%b8%e8%a7%81%e7%bb%9f%e8%ae%a1%e6%96%b9%e6%a1%88%e6%95%b4%e7%90%86%e6%b1%87%e6%80%bb","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=131827","title":{"rendered":"mysql \u5e38\u89c1\u7edf\u8ba1\u65b9\u6848\u6574\u7406\u6c47\u603b"},"content":{"rendered":"<p>\u6700\u8fd1\u7528MySQL\u505a\u7edf\u8ba1\u7684\u9700\u6c42\u6bd4\u8f83\u591a\uff0c\u8fd9\u91cc\u6574\u7406\u4e00\u4e9b\u5e38\u7528\u7684\u573a\u666f\u65b9\u4fbf\u540e\u671f\u67e5\u9605\uff0c\u540c\u65f6\u4e5f\u662f\u629b\u7816\u5f15\u7389\u7684\u8fc7\u7a0b\u3002\u5176\u4e2d\u5305\u62ec\u666e\u901a\u7684\u5206\u7ec4\u7edf\u8ba1\uff0c\u8fde\u7eed\u7684\u6bcf\u65e5\u7edf\u8ba1\uff0c\u533a\u95f4\u8303\u56f4\u7edf\u8ba1\u3002<\/p>\n<h3><a href=\"https:\/\/www.studytime.xin\/article\/#\u666e\u901a\u5206\u7ec4\u7edf\u8ba1\" title=\"\u666e\u901a\u5206\u7ec4\u7edf\u8ba1\"><\/a>\u666e\u901a\u5206\u7ec4\u7edf\u8ba1<\/h3>\n<ul>\n<li>\u573a\u666f\u4e00\uff1a\u6839\u636e\u8ba2\u5355\u72b6\u6001\u7edf\u8ba1\u8ba2\u5355\u6570\u91cf\u3002<br \/>\u4e00\u4e2a\u5f88\u5e38\u89c1\uff0c\u4e5f\u5f88\u7b80\u5355\u7684\u7edf\u8ba1\u9700\u6c42\u3002\u5176\u4e2d\u72b6\u6001\u5b57\u6bb5\u662f\u8ba2\u5355\u5b9e\u4f53\u7684\u4e00\u4e2a\u5c5e\u6027\u3002<\/li>\n<\/ul>\n<figure>\n<table>\n<tr>\n<td>\n<pre><span>1<\/span><br><span>2<\/span><br><\/pre>\n<\/td>\n<td>\n<pre><span>@Query(&quot;SELECT status, COUNT(id) FROM Order GROUP BY status&quot;)<\/span><br><span>fun summaryOrderByStatus(): Array&lt;Array&lt;String&gt;&gt;?<\/span><br><\/pre>\n<\/td>\n<\/tr>\n<\/table>\n<\/figure>\n<ul>\n<li>\u573a\u666f\u4e8c\uff1a\u6839\u636e\u8ba2\u5355\u4e2d\u5546\u54c1\u7c7b\u76ee\u7edf\u8ba1\u8ba2\u5355\u6570\u91cf\u548c\u91d1\u989d\u3002<br \/>\u6bd4\u573a\u666f\u4e00\u7a0d\u5fae\u9ebb\u70e6\u4e86\u4e00\u70b9\uff0c\u5546\u54c1\u5b57\u6bb5\u662f\u8ba2\u5355\u5b9e\u4f53\u7684\u4e00\u4e2a\u5c5e\u6027\uff0c\u800c\u7c7b\u76ee\u5b57\u6bb5\u624d\u662f\u5546\u54c1\u5b9e\u4f53\u7684\u4e00\u4e2a\u5c5e\u6027\u3002\u53c2\u8003\u4ee3\u7801\uff1a\uff08Kotlin\u8bed\u6cd5\uff09<\/li>\n<\/ul>\n<figure>\n<table>\n<tr>\n<td>\n<pre><span>1<\/span><br><span>2<\/span><br><\/pre>\n<\/td>\n<td>\n<pre><span>@Query(&quot;SELECT commodity.category, COUNT(id), SUM(finalPrice) FROM Order GROUP BY commodity.category&quot;)<\/span><br><span>fun summaryOrderByCommodityCategory(): Array&lt;Array&lt;String&gt;&gt;?<\/span><br><\/pre>\n<\/td>\n<\/tr>\n<\/table>\n<\/figure>\n<p>\u5c0f\u7ed3\uff1a<\/p>\n<ol>\n<li>\u5206\u7ec4\u7edf\u8ba1\u5c11\u4e0d\u4e86GROUP BY\u8bed\u53e5\uff0c\u5982\u679c\u9700\u8981\u52a0\u67e5\u8be2\u6761\u4ef6\uff0c\u8bf7\u5728\u5176\u524d\u9762\u6dfb\u52a0 WHERE \u8bed\u53e5\u3002<\/li>\n<li>\u7edf\u8ba1\u6570\u91cf\u7528COUNT\uff0c\u7edf\u8ba1\u603b\u548c\u7528SUM\u51fd\u6570\uff0c\u6709GROUP BY\u7684\u5730\u65b9\uff0c\u5c11\u4e0d\u4e86\u8fd9\u4e9b\u805a\u5408\u51fd\u6570\u3002<\/li>\n<li>\u7edf\u8ba1\u8fd4\u56de\u7684\u7ed3\u679c\u662f\u5b57\u7b26\u4e32\u7c7b\u578b\u7684\u4e8c\u7ef4\u6570\u7ec4\u3002<\/li>\n<li>\u4ee5\u5185\u5d4c\u5c5e\u6027\u5206\u7ec4\uff0c\u5982\u679c\u662fSpringDataJpa\u6846\u67b6\uff0c\u5219\u53ef\u4ee5\u76f4\u63a5\u901a\u8fc7\u201d\u5b9e\u4f53\u7c7b.\u5c5e\u6027\u540d\u201d\u7684\u65b9\u5f0f\u3002<\/li>\n<\/ol>\n<h3><a href=\"https:\/\/www.studytime.xin\/article\/#\u6bcf\u65e5\u7edf\u8ba1\" title=\"\u6bcf\u65e5\u7edf\u8ba1\"><\/a>\u6bcf\u65e5\u7edf\u8ba1<\/h3>\n<p>\u5728\u505a\u6bcf\u65e5\uff0c\u6bcf\u5468\uff0c\u6bcf\u6708\u7edf\u8ba1\u65f6\uff0c\u9047\u5230\u8fd4\u56de\u65e5\u671f\u4e0d\u662f\u8fde\u7eed\u7684\u60c5\u51b5\u3002<br \/>\u539f\u56e0\u662f\u6570\u636e\u5e93\u4e2d\u6ca1\u6709\u503c\uff0c\u800c\u6211\u4eec\u7406\u60f3\u72b6\u6001\u5e94\u8be5\u662f\uff1a\u5982\u679c\u6ca1\u6709\u503c\u5219\u9ed8\u8ba4\u4e3a\u96f6\uff0c\u4f7f\u5176\u6570\u636e\u662f\u8fde\u7eed\u7684\u65e5\u671f\u3002<\/p>\n<ul>\n<li>\u573a\u666f\u4e09\uff1a\u7edf\u8ba1\u7ed3\u679c\u65e5\u671f\u53ef\u80fd\u4e0d\u8fde\u7eed<br \/>\u5982\u679c\u6570\u636e\u5e93\u4e2d\u67d0\u4e2a\u65f6\u95f4\u6bb5\u6ca1\u6709\u503c\uff0c\u90a3\u7edf\u8ba1\u51fa\u6765\u7684\u7ed3\u679c\u4f1a\u7f3a\u8fd9\u6bb5\u65f6\u95f4\u3002\u53c2\u8003\u4ee3\u7801\uff1a\uff08sql\u8bed\u53e5\uff09<\/li>\n<\/ul>\n<figure>\n<table>\n<tr>\n<td>\n<pre><span>1<\/span><br><span>2<\/span><br><span>3<\/span><br><span>4<\/span><br><span>5<\/span><br><span>6<\/span><br><\/pre>\n<\/td>\n<td>\n<pre><span>-- \u7edf\u8ba1\u6bcf\u65e5<\/span><br><span>SELECT DATE_FORMAT(create_date,&#39;%Y-%m-%d&#39;) as days, COUNT(id) count FROM order GROUP BY days;<\/span><br><span>-- \u7edf\u8ba1\u6bcf\u5468<\/span><br><span>SELECT DATE_FORMAT(create_date,&#39;%Y-%u&#39;) as weeks, COUNT(id) count FROM order GROUP BY weeks;<\/span><br><span>-- \u7edf\u8ba1\u6bcf\u6708<\/span><br><span>SELECT DATE_FORMAT(create_date,&#39;%Y-%m&#39;) as months, COUNT(id) count FROM order GROUP BY months;<\/span><br><\/pre>\n<\/td>\n<\/tr>\n<\/table>\n<\/figure>\n<ul>\n<li>\u573a\u666f\u56db\uff1a\u7edf\u8ba1\u7ed3\u679c\u65e5\u671f\u8fde\u7eed<br \/>\u8981\u8ba9\u65e5\u671f\u8fde\u7eed\uff0c\u53c8\u8981\u4ee3\u7801\u4f18\u96c5\u3002\u8bf4\u5b9e\u8bdd\uff0c\u56f0\u6270\u4e86\u6211\u5f88\u4e45\uff0c\u4e00\u76f4\u6ca1\u6709\u627e\u5230\u5f88\u597d\u7684\u89e3\u51b3\u65b9\u6cd5\uff0c\u867d\u7136\u76ee\u524d\u8fd9\u4e2a\u65b9\u6cd5\u5f88\u632b\u3002\u4f46\u53ef\u4ee5\u89e3\u51b3\u95ee\u9898\u3002\u6bd5\u7adf\u6293\u5230\u8001\u9f20\u7684\u90fd\u662f\u597d\u732b\u3002\u5982\u679c\u5404\u4f4d\u6709\u597d\u7684\u5efa\u8bae\uff0c\u671b\u8d50\u6559\uff01<\/li>\n<\/ul>\n<p>\u89e3\u51b3\u601d\u8def\uff1a<\/p>\n<ol>\n<li>\u7b2c\u4e00\u6b65\uff1a\u521b\u5efa\u4e00\u5f20date_summary\u8f85\u52a9\u8868\uff0c\u5b57\u6bb5\u53ea\u9700\u8981\u6709date\u548ccount\uff08\u9ed8\u8ba4\u503c\u4e3a\u96f6\uff09\u3002<\/li>\n<li>\u7b2c\u4e8c\u6b65\uff1a\u5148\u5411date_summary\u8868\u63d2\u516510\u5e74\u5185\u7684\u6570\u636e\u3002<\/li>\n<li>\u7b2c\u4e09\u6b65\uff1a\u901a\u8fc7UNION ALL \u8054\u5408\u67e5\u8be2\uff0c\u5c06\u7a7a\u7f3a\u7684\u65e5\u671f\u8865\u4e0a\u3002<\/li>\n<li>\u7b2c\u4e8c\u6b65\u53c2\u8003\u4ee3\u7801\uff08Kotlin\u8bed\u6cd5\uff09<\/li>\n<\/ol>\n<p>\u7b2c\u4e8c\u6b65\u53c2\u8003\u4ee3\u7801\uff08Kotlin\u8bed\u6cd5\uff09<\/p>\n<figure>\n<table>\n<tr>\n<td>\n<pre><span>1<\/span><br><span>2<\/span><br><span>3<\/span><br><span>4<\/span><br><span>5<\/span><br><span>6<\/span><br><span>7<\/span><br><span>8<\/span><br><span>9<\/span><br><span>10<\/span><br><span>11<\/span><br><span>12<\/span><br><span>13<\/span><br><span>14<\/span><br><span>15<\/span><br><span>16<\/span><br><span>17<\/span><br><\/pre>\n<\/td>\n<td>\n<pre><span>val startDate &#x3D; Calendar.getInstance()<\/span><br><span>startDate.set(2018, 6, 1)<\/span><br><span>val startTIme &#x3D; startDate.timeInMillis<\/span><br><span>val endDate &#x3D; Calendar.getInstance()<\/span><br><span>endDate.set(2028, 11, 30)<\/span><br><span>val endTime &#x3D; endDate.timeInMillis<\/span><br><span>val oneDay &#x3D; 1000 * 60 * 60 * 24L<\/span><br><span>var time &#x3D; startTIme<\/span><br><span>val dates: MutableList&lt;DateSummary&gt; &#x3D; arrayListOf()<\/span><br><span>while (time&lt;&#x3D;endTime) &#123;<\/span><br><span>   val dateSummary &#x3D; DateSummary()<\/span><br><span>   dateSummary.date &#x3D; SimpleDateFormat(&quot;yyyy-MM-dd&quot;).format(Date(time))<\/span><br><span>   dateSummary.count &#x3D; 0<\/span><br><span>   dates.add(dateSummary)<\/span><br><span>   time +&#x3D; oneDay<\/span><br><span>&#125;<\/span><br><span>dateSummaryRepository.saveAll(dates)<\/span><br><\/pre>\n<\/td>\n<\/tr>\n<\/table>\n<\/figure>\n<p>\u7b2c\u4e09\u6b65\u7edf\u8ba1\u6bcf\u65e5\u7684SQL\u8bed\u53e5<\/p>\n<figure>\n<table>\n<tr>\n<td>\n<pre><span>1<\/span><br><span>2<\/span><br><span>3<\/span><br><span>4<\/span><br><span>5<\/span><br><span>6<\/span><br><span>7<\/span><br><span>8<\/span><br><span>9<\/span><br><span>10<\/span><br><span>11<\/span><br><span>12<\/span><br><span>13<\/span><br><span>14<\/span><br><span>15<\/span><br><span>16<\/span><br><span>17<\/span><br><span>18<\/span><br><span>19<\/span><br><span>20<\/span><br><span>21<\/span><br><span>22<\/span><br><span>23<\/span><br><span>24<\/span><br><span>25<\/span><br><span>26<\/span><br><span>27<\/span><br><span>28<\/span><br><\/pre>\n<\/td>\n<td>\n<pre><span>SELECT<\/span><br><span>   summary.oneDay,<\/span><br><span>   summary.count <\/span><br><span>FROM<\/span><br><span>   (<\/span><br><span>   SELECT<\/span><br><span>       DATE_FORMAT( created_date, &#39;%Y-%m-%d&#39; ) oneDay,<\/span><br><span>       COUNT(id) count <\/span><br><span>   FROM<\/span><br><span>       service_order <\/span><br><span>   WHERE created_date BETWEEN &quot;2018-06-01&quot; and &quot;2018-08-01&quot;<\/span><br><span>   GROUP BY oneDay <\/span><br><span>   UNION ALL<\/span><br><span>       (<\/span><br><span>       SELECT<\/span><br><span>           DATE_FORMAT( date, &#39;%Y-%m-%d&#39; ) templateDay,<\/span><br><span>           count<\/span><br><span>       FROM<\/span><br><span>           date_summary<\/span><br><span>       WHERE date BETWEEN &quot;2018-06-01&quot; and &quot;2018-08-01&quot;<\/span><br><span>       GROUP BY<\/span><br><span>           templateDay<\/span><br><span>       ) <\/span><br><span>   ) summary <\/span><br><span>GROUP BY<\/span><br><span>   summary.oneDay <\/span><br><span>ORDER BY<\/span><br><span>   summary.oneDay ASC<\/span><br><\/pre>\n<\/td>\n<\/tr>\n<\/table>\n<\/figure>\n<p>\u5c0f\u7ed3\uff1a<\/p>\n<ol>\n<li>MySQL\u7684DATE_FORMAT(date,format) \u51fd\u6570\u7528\u4e8e\u4ee5\u4e0d\u540c\u7684\u683c\u5f0f\u663e\u793a\u65e5\u671f\/\u65f6\u95f4\u6570\u636e\uff0c\u6587\u7ae0\u540e\u9762\u4f1a\u8be6\u7ec6\u4ecb\u7ecd<\/li>\n<li>MySQL\u7684UNION \u64cd\u4f5c\u7b26\u7528\u4e8e\u5408\u5e76\u4e24\u4e2a\u6216\u591a\u4e2aSELECT\u8bed\u53e5\u7684\u7ed3\u679c\u96c6\uff0c\u6587\u7ae0\u540e\u9762\u4f1a\u8be6\u7ec6\u4ecb\u7ecd<\/li>\n<\/ol>\n<h3><a href=\"https:\/\/www.studytime.xin\/article\/#\u533a\u95f4\u8303\u56f4\u7edf\u8ba1\" title=\"\u533a\u95f4\u8303\u56f4\u7edf\u8ba1\"><\/a>\u533a\u95f4\u8303\u56f4\u7edf\u8ba1<\/h3>\n<p>\u8fd9\u662f\u4e00\u4e2a\u8f83\u4e3a\u5e38\u89c1\u7684\u9700\u6c42\uff0c\u6bd4\u5982\u6309\u7167\u5e74\u9f84\u6bb5\u7edf\u8ba1\u4eba\u5458\u5206\u5e03\u60c5\u51b5\uff0c\u751a\u81f3\u8981\u6c42\u5206\u522b\u7edf\u8ba1\u7537\u5973\u4eba\u6570\u5206\u5e03\u60c5\u51b5\u3002<\/p>\n<ul>\n<li>\u573a\u666f\u4e94\uff1a\u6839\u636e\u5c0f\u533a\u5e74\u9f84\u6bb5\u7edf\u8ba1\u4eba\u6570<br \/>\u53ea\u6839\u636e\u5e74\u9f84\u8303\u56f4\u7edf\u8ba1\uff0c\u6ca1\u6709\u5176\u4ed6\u9650\u5236\u6761\u4ef6\uff0c\u4f7f\u7528SUM\u53ea\u9700\u8981\u52a0\u4e00\u3002<\/li>\n<\/ul>\n<figure>\n<table>\n<tr>\n<td>\n<pre><span>1<\/span><br><span>2<\/span><br><\/pre>\n<\/td>\n<td>\n<pre><span>SELECT INTERVAL(age,10,20,30,40,50,60,70,80,90) AS ageRatio, <\/span><br><span>SUM(1) AS count FROM user GROUP BY ageRatio<\/span><br><\/pre>\n<\/td>\n<\/tr>\n<\/table>\n<\/figure>\n<ul>\n<li>\u573a\u666f\u516d\uff1a\u6839\u636e\u5c0f\u533a\u5e74\u9f84\u6bb5\u7edf\u8ba1\u7537\u5973\u4eba\u6570<br \/>\u5728\u573a\u666f\u4e94\u7684\u57fa\u7840\u4e0a\u591a\u4e86\u4e00\u4e2a\u533a\u5206\u6027\u522b\uff0c\u7528\u6d41\u7a0b\u63a7\u5236\u51fd\u6570\u6765\u8bbe\u7f6eSUM\u52a0\u4e00\u7684\u60c5\u51b5\u3002<\/li>\n<\/ul>\n<figure>\n<table>\n<tr>\n<td>\n<pre><span>1<\/span><br><span>2<\/span><br><span>3<\/span><br><\/pre>\n<\/td>\n<td>\n<pre><span>SELECT INTERVAL(age,10,20,30,40,50,60,70,80,90) AS ageRatio, <\/span><br><span>SUM(CASE WHEN sex&#x3D;1 THEN 1 ELSE 0 END) AS male,<\/span><br><span>SUM(CASE WHEN sex&#x3D;0 THEN 1 ELSE 0 END) AS female FROM user GROUP BY ageRatio<\/span><br><\/pre>\n<\/td>\n<\/tr>\n<\/table>\n<\/figure>\n<p>\u5c0f\u7ed3\uff1a<\/p>\n<ol>\n<li>\u901a\u8fc7\u533a\u95f4\u7edf\u8ba1\u9700\u8981\u4f7f\u7528MySQL\u7684INTERVAL\u51fd\u6570\uff0c\u7b2c\u4e00\u4e2a\u53c2\u6570\u662f\u9700\u8981\u6bd4\u8f83\u7684\u5b57\u6bb5\uff0c\u540e\u9762\u662f\u6bd4\u8f83\u7684\u533a\u95f4\uff0c\u503c\u5fc5\u987b\u4ece\u5c0f\u5230\u5927<\/li>\n<li>\u533a\u95f4\u7edf\u8ba1\u7684\u7ed3\u679c\u4e5f\u662f\u4e8c\u7ef4\u6570\u7ec4\uff0c\u6ce8\u610f\u8fd4\u56de\u7684\u7ed3\u679c\u53ef\u80fd\u4e0d\u662f\u8fde\u7eed\u7684\uff08\u8fd9\u91cc\u7684\u4e0d\u8fde\u7eed\u53ef\u4ee5\u7528\u4ee3\u7801\u89e3\u51b3\uff0c\u6bd5\u7adf\u533a\u95f4\u6570\u91cf\u8f83\u5c11\uff09\u3002\u7b2c\u4e00\u4e2a\u53c2\u6570\u8fd4\u56de\u7684\u662f\u533a\u95f4\u7684\u4e0b\u6807\uff0c\u4ece0\u5f00\u59cb\u3002<\/li>\n<li>\u5f53age\u7684\u503c\u5728\u533a\u95f4\u8303\u56f4\u5185\u5c31SUM\u52a0\u4e00\uff0c\u4e5f\u53ef\u4ee5\u901a\u8fc7\u6d41\u7a0b\u63a7\u5236\u51fd\u6570\uff08CASE WHEN THEN ELSE END\uff09\u6765\u5224\u65ad\u662f\u52a0\u4e00\u8fd8\u662f\u52a0\u96f6<\/li>\n<\/ol>\n<hr>\n<h3><a href=\"https:\/\/www.studytime.xin\/article\/#MySQL\u77e5\u8bc6\u70b9\" title=\"MySQL\u77e5\u8bc6\u70b9\"><\/a>MySQL\u77e5\u8bc6\u70b9<\/h3>\n<p>\u77e5\u9053\u73b0\u5728\u90fd\u662f\u5feb\u9910\u6587\u5316\uff0c\u5927\u5bb6\u90fd\u5f88\u5fd9\uff0c\u5f88\u5c11\u6709\u65f6\u95f4\u53bb\u63e3\u6469\u5404\u8bed\u6cd5\u7684\u7279\u70b9\u3002\u6240\u4ee5\u5148\u628a\u5e38\u7528\u7684\u573a\u666f\u5199\u5728\u524d\u9762\uff0c\u8bed\u6cd5\u77e5\u8bc6\u5199\u5728\u540e\u9762\u3002<\/p>\n<ul>\n<li>GROUP BY \u5206\u7ec4<\/li>\n<\/ul>\n<ol>\n<li>\u5206\u7ec4\u4e00\u822c\u4e0e\u805a\u5408\u51fd\u6570\u4e00\u8d77\u4f7f\u7528\u5982SUM\uff0cCOUNT\u7b49<\/li>\n<li>GROUP BY \u5728WHERE \u8bed\u53e5\u4e4b\u540e<\/li>\n<\/ol>\n<ul>\n<li>DATE_FORMAT \u65f6\u95f4\u683c\u5f0f\u5316<\/li>\n<\/ul>\n<ol>\n<li>\u7528\u6765\u4fee\u6539\u65f6\u95f4\u7684\u683c\u5f0f<\/li>\n<li>\u8bed\u6cd5\u683c\u5f0f: DATE_FORMAT(date,format) date\u5fc5\u987b\u662f\u5408\u683c\u7684\u65f6\u95f4\u53c2\u6570\uff0cformat\u662f\u8f93\u51fa\u65f6\u95f4\u683c\u5f0f<\/li>\n<li>\u5e38\u89c1\u7684format\u683c\u5f0f\u6709\uff1a<\/li>\n<\/ol>\n<ul>\n<li>%Y: 4\u4f4d\u6570\u7684\u5e74\uff0c<\/li>\n<li>%y: 2\u4f4d\u6570\u7684\u5e74\uff0c<\/li>\n<li>%m: 2\u4f4d\u6570\u7684\u6708\uff0800~12\uff09\uff0c<\/li>\n<li>%M: \u82f1\u6587\u5355\u8bcd\u7684\u6708\uff0c<\/li>\n<li>%d: 2\u4f4d\u6570\u7684\u65e5\uff0800~31\uff09\uff0c<\/li>\n<li>%u: \u5468\uff0c\u661f\u671f\u4e00\u662f\u4e00\u5468\u7684\u7b2c\u4e00\u6761\uff0c<\/li>\n<li>\u66f4\u591a\u53ef\u4ee5\u8bbf\u95eew3school<\/li>\n<\/ul>\n<ul>\n<li>UNION \u8054\u5408\u7ed3\u679c<\/li>\n<\/ul>\n<ol>\n<li>UNION\u53ef\u4ee5\u5408\u5e76\u3001\u8054\u5408\uff0c\u5c06\u591a\u6b21\u67e5\u8be2\u7ed3\u679c\u5408\u5e76\u6210\u4e00\u4e2a\u7ed3\u679c\uff0c\u901a\u8fc7\u67e5\u8be2\u7ed3\u679c\u5408\u5e76\u89e3\u51b3\u4e86\u7edf\u8ba1\u4e0d\u8fde\u7eed\u7684\u60c5\u51b5\u3002<\/li>\n<li>\u591a\u6761\u67e5\u8be2\u8bed\u53e5\u7684\u5217\u6570\u5fc5\u987b\u4e00\u81f4\uff0c\u5404\u5217\u7684\u987a\u5e8f\u6700\u597d\u4e00\u81f4\u3002\u573a\u666f\u56db\u4e2d\uff0c\u4e24\u6761sql\u90fd\u53ea\u67e5\u8be2\u4e86date\u548ccount\uff0c\u4e14\u987a\u5e8f\u4fdd\u6301\u4e00\u81f4\u3002<\/li>\n<li>union \u53bb\u91cd\uff0cunion all\u5305\u542b\u91cd\u590d\u9879<\/li>\n<\/ol>\n<ul>\n<li>INTERVAL \u6bd4\u8f83\u95f4\u8ddd<\/li>\n<\/ul>\n<ol>\n<li>INTERVAL()\u51fd\u6570\u662f\u6bd4\u8f83\u5217\u8868(N, arg1, arg2, arg3\u2026argN)\u4e2d\u7684N\u503c\u3002<\/li>\n<li>INTERVAL()\u51fd\u6570\u5982\u679cN&lt;arg1\u5219\u8fd4\u56de0\uff0c\u5982\u679cN&lt;arg2\u5219\u8fd4\u56de1\uff0c\u5982\u679cN&lt;arg3\u5219\u8fd4\u56de2\uff0c\u5982\u679cN\u4e3aNULL\uff0c\u5b83\u5c06\u8fd4\u56de-1\u3002<\/li>\n<li>\u5217\u8868\u503c\u5fc5\u987b\u662farg1 &lt; arg2 &lt; arg3 \u7684\u5f62\u5f0f\u624d\u80fd\u6b63\u5e38\u5de5\u4f5c\u3002<\/li>\n<\/ol>\n<ul>\n<li>\u6d41\u7a0b\u63a7\u5236\u51fd\u6570<\/li>\n<\/ul>\n<ol>\n<li>case when then else end \u662f\u6d41\u7a0b\u63a7\u5236\u51fd\u6570\u4e2d\u7684\u4e00\u79cd\uff0c\u8fd8\u6709\u4e00\u79cd\u662fif\u51fd\u6570<\/li>\n<li>\u4f7f\u7528\u8bed\u6cd5\uff1a<\/li>\n<\/ol>\n<figure>\n<table>\n<tr>\n<td>\n<pre><span>1<\/span><br><span>2<\/span><br><span>3<\/span><br><span>4<\/span><br><span>5<\/span><br><span>6<\/span><br><\/pre>\n<\/td>\n<td>\n<pre><span>case <\/span><br><span>when \u6761\u4ef61 then \u503c1<\/span><br><span>when \u6761\u4ef62 then \u503c2<\/span><br><span>...<\/span><br><span>else \u503cn<\/span><br><span>end<\/span><br><\/pre>\n<\/td>\n<\/tr>\n<\/table>\n<\/figure>\n","protected":false},"excerpt":{"rendered":"<p>\u6700\u8fd1\u7528MySQL\u505a\u7edf\u8ba1\u7684\u9700\u6c42\u6bd4\u8f83\u591a&hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[],"tags":[],"_links":{"self":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/131827"}],"collection":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=131827"}],"version-history":[{"count":0,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/131827\/revisions"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=131827"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=131827"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=131827"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}