{"id":962,"date":"2021-01-20T00:25:51","date_gmt":"2021-01-19T15:25:51","guid":{"rendered":"https:\/\/skyit.biz\/?p=962"},"modified":"2021-01-20T00:25:52","modified_gmt":"2021-01-19T15:25:52","slug":"%e7%ac%ac2%e7%ab%a0select%e6%96%87%e3%82%92%e4%bd%bf%e7%94%a8%e3%81%97%e3%81%9f%e3%83%87%e3%83%bc%e3%82%bf%e3%81%ae%e5%8f%96%e5%be%97","status":"publish","type":"post","link":"https:\/\/skyit.biz\/?p=962","title":{"rendered":"\u7b2c2\u7ae0\tSELECT\u6587\u3092\u4f7f\u7528\u3057\u305f\u30c7\u30fc\u30bf\u306e\u53d6\u5f97"},"content":{"rendered":"\n<p>\u25bcKEY WORD<br>\u5c04\u5f71\u3001\u9078\u629e\u3001\u7d50\u5408<br>SELECT\u6587<br>SELECT\u53e5\u3068FROM\u53e5<br>\u7b97\u51fa\u6f14\u7b97\u5b50<br>\u6f14\u7b97\u5b50\u306e\u512a\u5148\u9806\u4f4d<br>NULL\u5024<br>\u5217\u5225\u540d<br>\u4ee3\u66ff\u5f15\u7528\u7b26\uff08q\uff09\u6f14\u7b97\u5b50<br>DISTINCT<\/p>\n\n\n\n<p>\u25bc\u5c04\u5f71<br>\u7279\u5b9a\u306e\u5217\u3092\u9078\u629e\u3059\u308b\u3002SELECT\u53e5\u3067\u5217\u540d\u3092\u6307\u5b9a\u3057\u3001\u7279\u5b9a\u306e\u5217\u30c7\u30fc\u30bf\u3060\u3051\u3092\u691c\u7d22\u3059\u308b\u3002<br>WHERE\u53e5\u3092\u4f7f\u7528\u3057\u3066\u3001\u6761\u4ef6\u3092\u7d5e\u308a\u8fbc\u3080\u3068\u3044\u3046\u306e\u306f\u3001\u542b\u307e\u308c\u306a\u3044\u3002<br>\u25bc\u9078\u629e<br>\u8868\u5185\u306e\u884c\u3092\u9078\u629e\u3059\u308b\u3002<br>WHERE\u53e5\u3067\u884c\u306e\u9078\u629e\u6761\u4ef6\u3092\u6307\u5b9a\u3057\u3001\u7279\u5b9a\u306e\u884c\u3060\u3051\u3092\u691c\u7d22\u3059\u308b\u3002<\/p>\n\n\n\n<p>\u25bc\u7d50\u5408<br>\u8868\u3092\u7d50\u5408\u3059\u308b\u3002<br>\u8907\u6570\u306e\u8868\u304b\u3089\u95a2\u9023\u3059\u308b\u60c5\u5831\u3092\u30011\u3064\u306eSELECT\u6587\u3067\u691c\u7d22\u3067\u304d\u308b\u3002<br>Oracle\u7d50\u5408\u69cb\u6587\u306e\u7d50\u5408\u3067\u306f\u3001FROM\u53e5\u3067\u8907\u6570\u306e\u8868\u3092\u3001WHERE\u53e5\u3067\u7d50\u5408\u6761\u4ef6\u3092\u6307\u5b9a\u3059\u308b\u3002<br>\u4f8b\uff09<br>SELECT ENAME, DNAME FROM EMP, DEPT<br>WHERE EMP.DEPTNO = DEPT.DEPTNO;<\/p>\n\n\n\n<p>\u25a0NULL\u5024<br>NULL\u306f\u3001\u5024\u304c\u8a2d\u5b9a\u3055\u308c\u3066\u3044\u306a\u3044\u72b6\u614b\u3067\u3059\u3002<br>NULL\u5024\u3092\u5165\u529b\u3059\u308b\u3068\u306f\u3001\u5024\u3092\u5165\u529b\u3057\u306a\u3044\u3053\u3068\u3067\u3059\u3002<br>\u5024\u304c\u5b58\u5728\u3057\u306a\u3044\u306e\u3067\u3001\u6587\u5b57\u3068\u3057\u3066\u6271\u3046\u3053\u3068\u306f\u51fa\u6765\u306a\u3044\u3002<br>0\u3068\u7a7a\u767d\u306f\u305d\u308c\u305e\u308c\uff11\u3064\u306e\u5024\u3067\u3042\u308a\u3001NULL\u3068\u306f\u7570\u306a\u308b\u3002<br>\uff10\u306f\u8a08\u7b97\u304c\u3067\u304d\u308b\u304c\u3001NULL\u3092\u542b\u3080\u8a08\u7b97\u5f0f\u306e\u7d50\u679c\u306f\u3001NULL\u3068\u306a\u308b\u3002<br>0\u3092\u542b\u3080\u8a08\u7b97\u5f0f 0+10=10<br>NULL\u3092\u542b\u3080\u8a08\u7b97\u5f0f NULL+10=NULL<\/p>\n\n\n\n<p>DISTINCT\u3068UNIQUE\u306f\u3001\u540c\u7fa9\u3067\u3042\u308b\u3002<br>DISTINCT\u3068UNIQUE\u306f\u3001SELECT\u53e5\u306e\u4e2d\u3067\u5148\u982d\u306b1\u5ea6\u3060\u3051\u6307\u5b9a\u3059\u308b\u3002<\/p>\n\n\n\n<p>SQL\u306e\u7279\u5fb4\u306e\u4e00\u3064\u3068\u3057\u3066\u3001\u975e\u624b\u7d9a\u304d\u578b\u8a00\u8a9e\u3067\u3042\u308b\u3002<br>\u624b\u7d9a\u304d\u578b\u8a00\u8a9e\u306f\u3001IF\uff5eTHEN\uff5eELSE\u3001LOOP\u306a\u3069\u306e\u5236\u5fa1\u51e6\u7406\u69cb\u9020\u3092\u6301\u3061\u3001\u51e6\u7406\uff08\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\uff09\u3092\u8a18\u8ff0\u3067\u304d\u308b\u3002<br>SQL\u3060\u3051\u3067\u306f\u3001\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u3092\u8a18\u8ff0\u3059\u308b\u3053\u3068\u306f\u3067\u304d\u306a\u3044\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u25bcKEY WORD\u5c04\u5f71\u3001\u9078\u629e\u3001\u7d50\u5408SELECT\u6587SELECT\u53e5\u3068FROM\u53e5\u7b97\u51fa\u6f14\u7b97\u5b50\u6f14\u7b97\u5b50\u306e\u512a\u5148\u9806\u4f4dNULL\u5024\u5217\u5225\u540d\u4ee3\u66ff\u5f15\u7528\u7b26\uff08q\uff09\u6f14\u7b97\u5b50DISTINCT \u25bc\u5c04\u5f71\u7279\u5b9a\u306e\u5217\u3092\u9078\u629e\u3059\u308b\u3002SELECT\u53e5\u3067\u5217\u540d\u3092\u6307\u5b9a\u3057\u3001\u7279\u5b9a\u306e\u5217 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[52,12],"tags":[],"class_list":{"0":"post-962","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-bronze-sql-12c","7":"category-oracle"},"_links":{"self":[{"href":"https:\/\/skyit.biz\/index.php?rest_route=\/wp\/v2\/posts\/962","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/skyit.biz\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/skyit.biz\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/skyit.biz\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/skyit.biz\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=962"}],"version-history":[{"count":1,"href":"https:\/\/skyit.biz\/index.php?rest_route=\/wp\/v2\/posts\/962\/revisions"}],"predecessor-version":[{"id":963,"href":"https:\/\/skyit.biz\/index.php?rest_route=\/wp\/v2\/posts\/962\/revisions\/963"}],"wp:attachment":[{"href":"https:\/\/skyit.biz\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=962"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/skyit.biz\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=962"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/skyit.biz\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=962"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}