{"id":10133,"date":"2024-04-13T22:08:29","date_gmt":"2024-04-13T19:08:29","guid":{"rendered":"https:\/\/sunucun.com.tr\/bilgi\/?post_type=dt_articles&#038;p=10133"},"modified":"2026-02-06T21:49:43","modified_gmt":"2026-02-06T18:49:43","slug":"mysqlde-case-when-kullanimi-kosullara-bagli-olarak-farkli-degerler-dondurme","status":"publish","type":"post","link":"https:\/\/sunucun.com.tr\/blog\/mysqlde-case-when-kullanimi-kosullara-bagli-olarak-farkli-degerler-dondurme\/","title":{"rendered":"MySQL&#8217;de CASE WHEN Kullan\u0131m\u0131: Ko\u015fullara Ba\u011fl\u0131 Olarak Farkl\u0131 De\u011ferler D\u00f6nd\u00fcrme"},"content":{"rendered":"<!-- SEO Meta Description -->\r\n<p>MySQL&#8217;de CASE WHEN yap\u0131s\u0131n\u0131 kullanarak ko\u015fullara ba\u011fl\u0131 olarak farkl\u0131 de\u011ferler d\u00f6nd\u00fcrmeyi \u00f6\u011frenin. Bu makalede, CASE WHEN yap\u0131s\u0131n\u0131n nas\u0131l kullan\u0131laca\u011f\u0131n\u0131 ke\u015ffedin.<\/p>\r\n\r\n\r\n<p class=\"wp-block-paragraph\"><strong>Giri\u015f<\/strong><\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">MySQL, ili\u015fkisel veritaban\u0131 y\u00f6netim sistemlerinin en pop\u00fclerlerinden biridir ve geni\u015f bir kullan\u0131c\u0131 kitlesi taraf\u0131ndan tercih edilmektedir. Veritaban\u0131 sorgular\u0131 s\u0131ras\u0131nda, bazen belirli ko\u015fullara ba\u011fl\u0131 olarak farkl\u0131 de\u011ferler d\u00f6nd\u00fcrmek gerekebilir. Bu t\u00fcr durumlarda, MySQL&#8217;in CASE WHEN yap\u0131s\u0131 olduk\u00e7a kullan\u0131\u015fl\u0131d\u0131r. Bu makalede, MySQL&#8217;de &#8220;<a href=\"https:\/\/www.sunucun.com.tr\/blog\/dt-articles\/mysqlde-case-when-kullanimi-kosullara-bagli-olarak-farkli-degerler-dondurme\/\">CASE WHEN Kullan\u0131m\u0131: Ko\u015fullara Ba\u011fl\u0131 Olarak Farkl\u0131 De\u011ferler D\u00f6nd\u00fcrme<\/a>&#8221; ba\u015fl\u0131\u011f\u0131 alt\u0131nda ko\u015fullara ba\u011fl\u0131 olarak farkl\u0131 de\u011ferlerin nas\u0131l d\u00f6nd\u00fcr\u00fclece\u011fini inceleyece\u011fiz.<\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\"><strong>CASE WHEN Yap\u0131s\u0131 Nedir?<\/strong><\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">MySQL&#8217;de CASE WHEN yap\u0131s\u0131, belirli ko\u015fullara g\u00f6re farkl\u0131 de\u011ferler d\u00f6nd\u00fcrmek i\u00e7in kullan\u0131lan bir yap\u0131d\u0131r. Bu yap\u0131, genellikle SELECT sorgular\u0131nda veya UPDATE i\u015flemlerinde kullan\u0131l\u0131r. CASE WHEN yap\u0131s\u0131, if-else ifadesine benzer bir \u015fekilde \u00e7al\u0131\u015f\u0131r ve bir veya daha fazla ko\u015fulun sa\u011flan\u0131p sa\u011flanmad\u0131\u011f\u0131n\u0131 kontrol ederek sonu\u00e7lar\u0131 d\u00f6nd\u00fcr\u00fcr.<\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">CASE WHEN yap\u0131s\u0131n\u0131n temel kullan\u0131m\u0131 \u015fu \u015fekildedir:<\/p>\r\n\r\n\r\n\r\n<pre class=\"wp-block-code\"><code>SELECT \r\n    CASE \r\n        WHEN condition1 THEN result1\r\n        WHEN condition2 THEN result2\r\n        ...\r\n        ELSE default_result\r\n    END \r\n    AS column_alias\r\nFROM \r\n    your_table;\r\n<\/code><\/pre>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">Yukar\u0131daki \u00f6rnekte, &#8220;condition1&#8221; ve &#8220;condition2&#8221; gibi ko\u015fullar\u0131n sa\u011flan\u0131p sa\u011flanmad\u0131\u011f\u0131 kontrol edilir. \u0130lk sa\u011flanan ko\u015fulun sonucu olan &#8220;result1&#8221; veya &#8220;result2&#8221; gibi de\u011ferler d\u00f6nd\u00fcr\u00fcl\u00fcr. Hi\u00e7bir ko\u015ful sa\u011flanmazsa, &#8220;default_result&#8221; olarak belirtilen varsay\u0131lan de\u011fer d\u00f6nd\u00fcr\u00fcl\u00fcr.<\/p>\r\n\r\n\r\n\r\n<figure class=\"wp-block-image size-large is-resized\"><img fetchpriority=\"high\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/www.sunucun.com.tr\/blog\/\/wp-content\/uploads\/2024\/04\/Uninstall-MySQL-Ubuntu-1024x576.jpg\" alt=\"CASE WHEN Kullan\u0131m\u0131 \u00d6rne\u011fi\" class=\"wp-image-10129\" style=\"width:763px;height:auto\" srcset=\"https:\/\/sunucun.com.tr\/blog\/wp-content\/uploads\/2024\/04\/Uninstall-MySQL-Ubuntu-1024x576.jpg 1024w, https:\/\/sunucun.com.tr\/blog\/wp-content\/uploads\/2024\/04\/Uninstall-MySQL-Ubuntu-300x169.jpg 300w, https:\/\/sunucun.com.tr\/blog\/wp-content\/uploads\/2024\/04\/Uninstall-MySQL-Ubuntu-768x432.jpg 768w, https:\/\/sunucun.com.tr\/blog\/wp-content\/uploads\/2024\/04\/Uninstall-MySQL-Ubuntu.jpg 1200w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\"><strong>CASE WHEN Kullan\u0131m\u0131<\/strong><\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">CASE WHEN yap\u0131s\u0131n\u0131 kullanarak ko\u015fullara ba\u011fl\u0131 olarak farkl\u0131 de\u011ferler d\u00f6nd\u00fcrmek olduk\u00e7a basittir. Bu yap\u0131, \u00f6zellikle b\u00fcy\u00fck ve karma\u015f\u0131k sorgularda b\u00fcy\u00fck avantaj sa\u011flar. CASE WHEN, sadece SELECT sorgular\u0131nda de\u011fil, ayn\u0131 zamanda UPDATE, DELETE ve di\u011fer SQL i\u015flemlerinde de kullan\u0131labilir. Bu yap\u0131n\u0131n en yayg\u0131n kullan\u0131ld\u0131\u011f\u0131 yerler aras\u0131nda raporlama, veri d\u00f6n\u00fc\u015f\u00fcm\u00fc ve \u00f6zel i\u015f kurallar\u0131n\u0131 uygulama i\u015flemleri yer al\u0131r.<\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">Bir veritaban\u0131 y\u00f6neticisi olarak, CASE WHEN yap\u0131s\u0131n\u0131 veritaban\u0131 sorgular\u0131n\u0131zda kullanmak, verileri daha dinamik bir \u015fekilde i\u015flemenize olanak tan\u0131r. \u00d6zellikle, b\u00fcy\u00fck veri setlerinde, belirli ko\u015fullar alt\u0131nda farkl\u0131 sonu\u00e7lar d\u00f6nd\u00fcrmek gerekti\u011finde bu yap\u0131 olduk\u00e7a kullan\u0131\u015fl\u0131 hale gelir. \u00d6rne\u011fin, bir m\u00fc\u015fteri tablosunda belirli harcama miktarlar\u0131na g\u00f6re farkl\u0131 indirim oranlar\u0131 uygulamak i\u00e7in CASE WHEN yap\u0131s\u0131n\u0131 kullanabilirsiniz.<\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\"><strong>\u00d6rnekler<\/strong><\/p>\r\n\r\n\r\n\r\n<ul class=\"wp-block-list\">\r\n<li>\u00d6rnek olarak, bir \u00f6\u011frencinin notunu alal\u0131m ve bu nota g\u00f6re performans\u0131n\u0131 de\u011ferlendirelim:<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n<pre class=\"wp-block-code\"><code>SELECT \r\n    student_name,\r\n    CASE \r\n        WHEN grade >= 90 THEN 'AA'\r\n        WHEN grade >= 80 THEN 'BA'\r\n        WHEN grade >= 70 THEN 'BB'\r\n        WHEN grade >= 60 THEN 'CB'\r\n        WHEN grade >= 50 THEN 'CC'\r\n        ELSE 'FF'\r\n    END \r\n    AS performance\r\nFROM \r\n    students;\r\n<\/code><\/pre>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">Bu \u00f6rnekte, \u00f6\u011frencinin notuna g\u00f6re performans\u0131 de\u011ferlendirilir ve ilgili harf notu d\u00f6nd\u00fcr\u00fcl\u00fcr. CASE WHEN yap\u0131s\u0131, farkl\u0131 not aral\u0131klar\u0131na g\u00f6re uygun harf notunu d\u00f6nd\u00fcrmek i\u00e7in kullan\u0131l\u0131r.<\/p>\r\n\r\n\r\n\r\n<ul class=\"wp-block-list\" start=\"2\">\r\n<li>Bir m\u00fc\u015fterinin al\u0131\u015fveri\u015f tutar\u0131na g\u00f6re indirim uygulayal\u0131m:<\/li>\r\n<\/ul>\r\n\r\n\r\n\r\n<pre class=\"wp-block-code\"><code>SELECT \r\n    customer_name,\r\n    total_amount,\r\n    CASE \r\n        WHEN total_amount >= 1000 THEN total_amount * 0.1\r\n        WHEN total_amount >= 500 THEN total_amount * 0.05\r\n        ELSE total_amount\r\n    END \r\n    AS discounted_amount\r\nFROM \r\n    orders;\r\n<\/code><\/pre>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">Bu sorgu, m\u00fc\u015fterinin al\u0131\u015fveri\u015f tutar\u0131na g\u00f6re farkl\u0131 indirim oranlar\u0131n\u0131 uygular. CASE WHEN yap\u0131s\u0131, m\u00fc\u015fterinin harcama miktar\u0131na g\u00f6re uygun indirim oran\u0131n\u0131 belirler ve toplam tutar\u0131 g\u00fcnceller.<\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\"><strong>CASE WHEN ile \u00c7oklu Ko\u015fullar<\/strong><\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">CASE WHEN yap\u0131s\u0131n\u0131n esnekli\u011fi, birden fazla ko\u015fulun kontrol edilmesine olanak tan\u0131r. \u00d6rne\u011fin, birden fazla ko\u015fulun ayn\u0131 anda sa\u011flanmas\u0131 gerekti\u011finde, AND operat\u00f6r\u00fc ile bu ko\u015fullar birle\u015ftirilebilir. Bu, daha karma\u015f\u0131k sorgular\u0131n ger\u00e7ekle\u015ftirilmesine olanak tan\u0131r. Ayr\u0131ca, OR operat\u00f6r\u00fc ile farkl\u0131 ko\u015fullar aras\u0131nda se\u00e7im yap\u0131labilir.<\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">\u00d6rne\u011fin, bir \u00e7al\u0131\u015fan tablosunda hem maa\u015f hem de pozisyona g\u00f6re bonus hesaplamak isteyebilirsiniz. Bu durumda, CASE WHEN yap\u0131s\u0131n\u0131 kullanarak, maa\u015f aral\u0131\u011f\u0131na ve pozisyona ba\u011fl\u0131 olarak farkl\u0131 bonus oranlar\u0131 uygulayabilirsiniz.<\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\"><strong>Sonu\u00e7<\/strong><\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">Bu makalede, MySQL&#8217;de CASE WHEN yap\u0131s\u0131n\u0131 kullanarak ko\u015fullara ba\u011fl\u0131 olarak farkl\u0131 de\u011ferlerin nas\u0131l d\u00f6nd\u00fcr\u00fclece\u011fini \u00f6\u011frendik. &#8220;<a href=\"https:\/\/www.sunucun.com.tr\/blog\/dt-articles\/mysqlde-case-when-kullanimi-kosullara-bagli-olarak-farkli-degerler-dondurme\/\">MySQL&#8217;de CASE WHEN Kullan\u0131m\u0131: Ko\u015fullara Ba\u011fl\u0131 Olarak Farkl\u0131 De\u011ferler D\u00f6nd\u00fcrme<\/a>&#8221; ba\u015fl\u0131\u011f\u0131 alt\u0131nda ele ald\u0131\u011f\u0131m\u0131z bu yap\u0131, veritaban\u0131 sorgular\u0131n\u0131z\u0131 daha esnek hale getirir ve \u00e7e\u015fitli ko\u015fullara g\u00f6re farkl\u0131 sonu\u00e7lar elde etmenizi sa\u011flar. CASE WHEN yap\u0131s\u0131n\u0131 kullanarak, veritaban\u0131 i\u015flemlerinizde daha fazla kontrol sa\u011flayabilir ve istedi\u011finiz sonu\u00e7lar\u0131 elde edebilirsiniz.<\/p>\r\n\r\n","protected":false},"excerpt":{"rendered":"<p>MySQL&#8217;de CASE WHEN yap\u0131s\u0131n\u0131 kullanarak ko\u015fullara ba\u011fl\u0131 olarak farkl\u0131 de\u011ferler d\u00f6nd\u00fcrmeyi \u00f6\u011frenin. Bu makalede, CASE WHEN yap\u0131s\u0131n\u0131n nas\u0131l kullan\u0131laca\u011f\u0131n\u0131 ke\u015ffedin. Giri\u015f MySQL, ili\u015fkisel veritaban\u0131 y\u00f6netim sistemlerinin en pop\u00fclerlerinden biridir ve geni\u015f bir kullan\u0131c\u0131 kitlesi taraf\u0131ndan tercih edilmektedir. Veritaban\u0131 sorgular\u0131 s\u0131ras\u0131nda, bazen belirli ko\u015fullara ba\u011fl\u0131 olarak farkl\u0131 de\u011ferler d\u00f6nd\u00fcrmek gerekebilir. Bu t\u00fcr durumlarda, MySQL&#8217;in CASE WHEN&hellip;<\/p>\n","protected":false},"author":1,"featured_media":10135,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"footnotes":""},"categories":[1525,1521],"tags":[],"class_list":["post-10133","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-siber-guvenlik","category-teknoloji"],"_links":{"self":[{"href":"https:\/\/sunucun.com.tr\/blog\/wp-json\/wp\/v2\/posts\/10133","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sunucun.com.tr\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sunucun.com.tr\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sunucun.com.tr\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sunucun.com.tr\/blog\/wp-json\/wp\/v2\/comments?post=10133"}],"version-history":[{"count":1,"href":"https:\/\/sunucun.com.tr\/blog\/wp-json\/wp\/v2\/posts\/10133\/revisions"}],"predecessor-version":[{"id":16481,"href":"https:\/\/sunucun.com.tr\/blog\/wp-json\/wp\/v2\/posts\/10133\/revisions\/16481"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/sunucun.com.tr\/blog\/wp-json\/wp\/v2\/media\/10135"}],"wp:attachment":[{"href":"https:\/\/sunucun.com.tr\/blog\/wp-json\/wp\/v2\/media?parent=10133"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sunucun.com.tr\/blog\/wp-json\/wp\/v2\/categories?post=10133"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sunucun.com.tr\/blog\/wp-json\/wp\/v2\/tags?post=10133"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}