{"id":594,"date":"2021-02-05T10:29:18","date_gmt":"2021-02-05T02:29:18","guid":{"rendered":"https:\/\/qtvz.com\/?p=594"},"modified":"2021-02-05T10:29:31","modified_gmt":"2021-02-05T02:29:31","slug":"mysql%e4%b8%8d%e6%8e%a8%e8%8d%90%e4%bd%bf%e7%94%a8-%ef%bc%88is-not-null%ef%bc%89-%e5%92%8c-%ef%bc%88not-in-%e8%bf%9b%e8%a1%8c-%e5%ad%90%e6%9f%a5%e8%af%a2%ef%bc%89%e4%bb%a5%e5%8f%8a%e5%ae%83%e4%bb%ac","status":"publish","type":"post","link":"https:\/\/qtvz.com\/594.html","title":{"rendered":"MySQL\u4e0d\u63a8\u8350\u4f7f\u7528 \uff08is not null\uff09 \u548c \uff08not in \u8fdb\u884c \u5b50\u67e5\u8be2\uff09,\u4ee5\u53ca\u5b83\u4eec\u7684\u66ff\u4ee3\u67e5\u8be2\u65b9\u6cd5"},"content":{"rendered":"<!--wp-compress-html--><!--wp-compress-html no compression--><h4>MySQL\u4f18\u5316<\/h4>\n<h5>MySQL\u7684\u67e5\u8be2\u4e2d\uff0c\u5982\u679c\u4f7f\u7528\uff08not in\u8fdb\u884c\u5b50\u67e5\u8be2\uff09\u6216\u8005\uff08is not null\uff09\u540e\uff0c\u4f1a\u8ba9\u67e5\u8be2\u901f\u5ea6\u53d8\u5f97\u5f88\u6162\uff0c\u7b14\u8005\u5341\u5206\u4e0d\u5efa\u8bae\u4f7f\u7528\u3002\u4e0b\u9762\u6709\u7b14\u8005\u603b\u7ed3\u7684\u4ee3\u66ff\u65b9\u6cd5\u3002<\/h5>\n<pre><code>\u4ee3\u66ff  \uff08not in \u8fdb\u884c \u5b50\u67e5\u8be2 \uff09\uff1a\u5c06\u5b50\u67e5\u8be2 \u8f6c\u53d8\u4e3a \u8868\u8fde\u63a5\uff0c\u76f8\u5173\u7684\u903b\u8f91\u5199\u5728 \u8868\u8fde\u63a5 \u7684\u5173\u7cfb\u4e0a\n\n\u4ee3\u66ff  \uff08is not null\uff09\uff1a\u5c06 is not null  \u7684\u5b57\u6bb5\uff0c\u4f7f\u7528 ifnull\uff08\uff09\u66ff\u6362\u4e3a\u5176\u4ed6\u503c\uff0c\u7136\u540e ifnull\uff08\uff09\uff01=\u5176\u4ed6\u503c\uff0c\u5c31\u80fd\u8fdb\u884c\u7b5b\u9009\u4e86<\/code><\/pre>\n<h4>\u4f8b\u5b50<\/h4>\n<pre><code>select USER_NAME from test where USER_NAME is not null\nselect USER_NAME from test where (IFNULL(USER_NAME, &#039;kong&#039;) != &#039;kong&#039;) = 1<\/code><\/pre>\n<!--wp-compress-html no compression--><!--wp-compress-html-->","protected":false},"excerpt":{"rendered":"MySQL\u4f18\u5316 MySQL\u7684\u67e5\u8be2\u4e2d\uff0c\u5982\u679c\u4f7f\u7528\uff08not in\u8fdb\u884c\u5b50\u67e5\u8be2\uff09\u6216\u8005\uff08is not null\uff09\u540e\uff0c\u4f1a\u8ba9\u67e5\u8be2\u901f\u5ea6\u53d8\u5f97\u5f88\u6162\uff0c\u7b14\u8005\u5341\u5206\u4e0d\u5efa\u8bae\u4f7f\u7528\u3002\u4e0b\u9762\u6709\u7b14\u8005\u603b\u7ed3\u7684\u4ee3\u66ff\u65b9\u6cd5\u3002 \u4ee3\u66ff \uff08not in \u8fdb\u884c \u00b7\u00b7\u00b7","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[30],"tags":[],"views":3509,"_links":{"self":[{"href":"https:\/\/qtvz.com\/api\/wp\/v2\/posts\/594"}],"collection":[{"href":"https:\/\/qtvz.com\/api\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/qtvz.com\/api\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/qtvz.com\/api\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/qtvz.com\/api\/wp\/v2\/comments?post=594"}],"version-history":[{"count":2,"href":"https:\/\/qtvz.com\/api\/wp\/v2\/posts\/594\/revisions"}],"predecessor-version":[{"id":596,"href":"https:\/\/qtvz.com\/api\/wp\/v2\/posts\/594\/revisions\/596"}],"wp:attachment":[{"href":"https:\/\/qtvz.com\/api\/wp\/v2\/media?parent=594"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qtvz.com\/api\/wp\/v2\/categories?post=594"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qtvz.com\/api\/wp\/v2\/tags?post=594"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}