{"id":992,"date":"2010-07-06T13:29:34","date_gmt":"2010-07-06T04:29:34","guid":{"rendered":"http:\/\/www.moonmile.net\/blog\/archives\/992"},"modified":"2010-07-06T13:30:13","modified_gmt":"2010-07-06T04:30:13","slug":"linq%e3%81%a7%e5%a4%96%e9%83%a8%e7%b5%90%e5%90%88%e3%82%92%e5%ae%9f%e8%a3%85%e3%81%99%e3%82%8b","status":"publish","type":"post","link":"http:\/\/www.moonmile.net\/blog\/archives\/992","title":{"rendered":"LINQ\u3067\u5916\u90e8\u7d50\u5408\u3092\u5b9f\u88c5\u3059\u308b"},"content":{"rendered":"<p>\n    SQL \u3067\u5916\u90e8\u7d50\u5408\u3092\u3059\u308b\u5834\u5408\u306f\u3001\u3055\u304f\u3063\u3068 left join \u3084 *= \u306a\u3069\u3092\u4f7f\u3048\u3070\u826f\u3044\u306e\u3067\u3059\u304c\u3001LINQ \u3060\u3068\u3044\u307e\u3044\u3061\u4e0d\u660e\u3002\n<\/p>\n<p>\n    \u3060\u3063\u305f\u306e\u3067\u3001\u63a2\u3057\u3066\u307f\u307e\u3057\u305f\u3002\n<\/p>\n<p>\n    Visual Studio 2010 &#8211; Visual C#<br \/>\n    \u65b9\u6cd5 : \u5de6\u5916\u90e8\u7d50\u5408\u3092\u5b9f\u884c\u3059\u308b (C# \u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0 \u30ac\u30a4\u30c9)<br \/>\n    <a href=\"http:\/\/msdn.microsoft.com\/ja-jp\/library\/bb397895.aspx\">http:\/\/msdn.microsoft.com\/ja-jp\/library\/bb397895.aspx<\/a>\n<\/p>\n<p>\n    \u3068\u3044\u3046\u611f\u3058\u3067\u3001\u30e2\u30ed\u3001\u305d\u306e\u307e\u307e\u306e\u8a18\u4e8b\u304c\u3042\u308a\u307e\u3057\u305f\u3002\u4ee5\u524d\u306f\u3001LINQ\u95a2\u4fc2\u306f\u8abf\u3079\u308b\u306e\u304c\u5927\u5909\u3060\u3063\u305f\u306e\u3067\u3059\u304c\u3001\u3053\u308c\u306f\u826f\u3055\u305d\u3046\u3067\u3059\u306d\u3002\n<\/p>\n<p>\n    \u5099\u5fd8\u9332\u3082\u8fbc\u307f\u3067\u3001\u89e3\u8aac\u3092\u52a0\u3048\u3066\u304a\u304f\u3068\u3001\n<\/p>\n<ul>\n<li>Person\u3001Pet \u3068\u3044\u3046\u30c6\u30fc\u30d6\u30eb\u304c\u3042\u308a\u307e\u3059\u3002\n    <\/li>\n<li>Person\uff08\u4eba\uff09\u306f\u3001Pet\uff08\u30da\u30c3\u30c8\uff09\u3092\u98fc\u3063\u3066\u3044\u308b\u3001\u3068\u3044\u3046\u30a4\u30e1\u30fc\u30b8\u3067\u3059\u306d\u3002\n    <\/li>\n<li>Person\u306b\u306f\u3001\u30da\u30c3\u30c8\u3092\u98fc\u3063\u3066\u3044\u306a\u3044\u4eba\u3082\u3044\u307e\u3059\u3002\n    <\/li>\n<\/ul>\n<blockquote style=\"MARGIN-RIGHT: 0px\" dir=\"ltr\">\n<p>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; public class Person<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; {<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; public string FirstName { get; set; }<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; public int? PetID { get; set; }<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; public class Pet<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; {<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; public int ID { get; set; }<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; public string PetName { get; set; }<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; List&lt;Person&gt; persons;<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; List&lt;Pet&gt; pets;\n    <\/p>\n<\/blockquote>\n<p>\n    \u3053\u3093\u306a\u98a8\u306b\u30c7\u30fc\u30bf\u3092\u521d\u671f\u5316\u3057\u3066\u304a\u304d\u307e\u3059\u3002\n<\/p>\n<blockquote style=\"MARGIN-RIGHT: 0px\" dir=\"ltr\">\n<p>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; \/\/ \u521d\u671f\u5316<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; private void button1_Click(object sender, EventArgs e)<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; {<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; persons = new List&lt;Person&gt;();<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; persons.Add(new Person() { FirstName = &#8220;masuda&#8221;, PetID = 1 });<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; persons.Add(new Person() { FirstName = &#8220;tomoaki&#8221;, PetID = null });<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; persons.Add(new Person() { FirstName = &#8220;kyonpu&#8221;, PetID = 2 });\n    <\/p>\n<p>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; pets = new List&lt;Pet&gt;();<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; pets.Add( new Pet() { ID=1, PetName=&#8221;taro&#8221; });<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; pets.Add( new Pet() { ID=2, PetName=&#8221;risumo&#8221; });<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }\n    <\/p>\n<\/blockquote>\n<p>\n    \u25a0\u30da\u30c3\u30c8\u3092\u98fc\u3063\u3066\u3044\u308b\u4eba\uff08\u5185\u90e8\u7d50\u5408\uff09\n<\/p>\n<blockquote style=\"MARGIN-RIGHT: 0px\" dir=\"ltr\">\n<p>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; \/\/ \u5185\u90e8\u7d50\u5408<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; private void button2_Click(object sender, EventArgs e)<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; {<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; \/\/ \u30da\u30c3\u30c8\u304c\u3044\u308b\u4eba\u3092\u8868\u793a<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; var ret = from pe in persons<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; join pet in pets on pe.PetID equals pet.ID<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; select new { pe.FirstName, pet.PetName };\n    <\/p>\n<p>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; foreach (var it in ret)<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; {<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Debug.Print(it.ToString());<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }\n    <\/p>\n<\/blockquote>\n<p>\n    \u25a0\u30da\u30c3\u30c8\u3092\u98fc\u3063\u3066\u3044\u308b\u4eba\u3082\u305d\u3046\u3067\u306a\u3044\u4eba\u3082\u8868\u793a\uff08\u5916\u90e8\u7d50\u5408\uff09\n<\/p>\n<blockquote style=\"MARGIN-RIGHT: 0px\" dir=\"ltr\">\n<p>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; \/\/ \u5916\u90e8\u7d50\u5408<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; private void button3_Click(object sender, EventArgs e)<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; {<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; \/\/ \u30da\u30c3\u30c8\u304c\u3044\u308b\/\u3044\u306a\u3044\u306b\u95a2\u308f\u3089\u305a\u8868\u793a<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; var ret = from pe in persons<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; join pet in pets on pe.PetID equals pet.ID into sub<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; from t in sub.DefaultIfEmpty()<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; select new {&nbsp; pe.FirstName, PetName = ( t == null ? &#8220;&#8221;: t.PetName )};\n    <\/p>\n<p>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; foreach (var it in ret)<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; {<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Debug.Print(it.ToString());<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }\n    <\/p>\n<\/blockquote>\n<p>\n    \u25a0\u30da\u30c3\u30c8\u3092\u98fc\u3063\u3066\u3044\u306a\u3044\u4eba\u3060\u3051\u3092\u8868\u793a\uff08null\u6bd4\u8f03\uff09\n<\/p>\n<blockquote style=\"MARGIN-RIGHT: 0px\" dir=\"ltr\">\n<p>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; \/\/ \u5916\u90e8\u7d50\u5408(null\u306e\u307f\u62bd\u51fa)<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; private void button4_Click(object sender, EventArgs e)<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; {<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; \/\/ \u30da\u30c3\u30c8\u304c\u3044\u306a\u3044\u4eba\u3092\u8868\u793a<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; var ret = from pe in persons<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; join pet in pets on pe.PetID equals pet.ID into sub<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; from t in sub.DefaultIfEmpty()<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; where t == null<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; select new { pe.FirstName };\n    <\/p>\n<p>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; foreach (var it in ret)<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; {<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Debug.Print(it.ToString());<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }<br \/>\n        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; }\n    <\/p>\n<\/blockquote>\n<p>\n    \u3053\u3093\u306a\u98a8\u306b\u3001\u4e00\u5ea6 into \u3092\u4f7f\u3063\u3066\u30b5\u30d6\u30c6\u30fc\u30d6\u30eb\uff08sub\uff09\u3092\u7528\u610f\u3057\u3066\u304b\u3089\u3001DefaultIfEmpty \u30e1\u30bd\u30c3\u30c9\u3067\u5916\u90e8\u7d50\u5408\u3092\u5b9f\u73fe\u3059\u308b\u3001\u3068\u3044\u3046\u65b9\u6cd5\u306b\u306a\u308a\u307e\u3059\u3002\n<\/p>\n<p>\n    &nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>SQL \u3067\u5916\u90e8\u7d50\u5408\u3092\u3059\u308b\u5834\u5408\u306f\u3001\u3055\u304f\u3063\u3068 left join \u3084 *= \u306a\u3069\u3092\u4f7f\u3048\u3070\u826f\u3044\u306e\u3067\u3059\u304c\u3001LINQ \u3060\u3068\u3044\u307e\u3044\u3061\u4e0d\u660e\u3002 \u3060\u3063\u305f\u306e\u3067\u3001\u63a2\u3057\u3066\u307f\u307e\u3057\u305f\u3002 Visual Studio 2010 &#8211; Visu &hellip; <a href=\"http:\/\/www.moonmile.net\/blog\/archives\/992\">\u7d9a\u304d\u3092\u8aad\u3080 <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[3],"tags":[],"class_list":["post-992","post","type-post","status-publish","format-standard","hentry","category-dev"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"http:\/\/www.moonmile.net\/blog\/wp-json\/wp\/v2\/posts\/992","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.moonmile.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.moonmile.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.moonmile.net\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/www.moonmile.net\/blog\/wp-json\/wp\/v2\/comments?post=992"}],"version-history":[{"count":3,"href":"http:\/\/www.moonmile.net\/blog\/wp-json\/wp\/v2\/posts\/992\/revisions"}],"predecessor-version":[{"id":995,"href":"http:\/\/www.moonmile.net\/blog\/wp-json\/wp\/v2\/posts\/992\/revisions\/995"}],"wp:attachment":[{"href":"http:\/\/www.moonmile.net\/blog\/wp-json\/wp\/v2\/media?parent=992"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.moonmile.net\/blog\/wp-json\/wp\/v2\/categories?post=992"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.moonmile.net\/blog\/wp-json\/wp\/v2\/tags?post=992"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}