{"id":387,"date":"2025-01-26T15:54:24","date_gmt":"2025-01-26T06:54:24","guid":{"rendered":"https:\/\/se-pg-toolbox.com\/?p=387"},"modified":"2025-01-26T15:55:56","modified_gmt":"2025-01-26T06:55:56","slug":"sql%e3%81%a7null%e3%82%920%e3%82%84%e7%a9%ba%e6%96%87%e5%ad%97%e3%81%ab%e5%a4%89%e6%8f%9b%e3%81%99%e3%82%8b%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/se-pg-toolbox.com\/?p=387","title":{"rendered":"SQL\u3067NULL\u30920\u3084\u7a7a\u6587\u5b57\u306b\u5909\u63db\u3059\u308b\u65b9\u6cd5"},"content":{"rendered":"\n

\u4eca\u56de\u306fSQL\u3067NULL\u30920\u3084\u7a7a\u6587\u5b57\u306b\u5909\u63db\u3059\u308b\u65b9\u6cd5\u3092\u8aac\u660e\u3057\u307e\u3059\u3002

\u30d7\u30ed\u30b0\u30e9\u30e0\u3067\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u4e0a\u3067\u30c7\u30fc\u30bf\u53d6\u5f97\u306e\u30af\u30a8\u30ea\u3092\u5b9f\u884c\u3055\u305b\u3001\u5b9f\u884c\u7d50\u679c\u3092\u53d7\u3051\u53d6\u308b\u51e6\u7406\u3092\u66f8\u304f\u5834\u5408\u3001\u30af\u30a8\u30ea\u304c\u8fd4\u3059NULL\u3092\u305d\u306e\u307e\u307e\u4f7f\u3044\u305f\u304f\u306a\u3044\u3068\u3044\u3046\u306e\u306f\u3001\u307e\u3042\u307e\u3042\u826f\u304f\u3042\u308b\u3053\u3068\u3067\u3059\u3002

\u306a\u306e\u3067\u3001\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3092\u4f7f\u7528\u3059\u308b\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u958b\u767a\u3059\u308b\u57fa\u672c\u7684\u306a\u77e5\u8b58\u3068\u3057\u3066SQL\u3067NULL\u3092\u7a7a\u6587\u5b57\u30840\u306b\u5909\u63db\u3059\u308b\u65b9\u6cd5\u306f\u304d\u3061\u3093\u3068\u77e5\u3063\u3066\u304a\u304f\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002

\u4eca\u56de\u306fNULL\u304c\u767a\u751f\u3059\u308b\u30af\u30a8\u30ea\u3092\u4f8b\u306b\u6319\u3052\u3001\u305d\u3053\u304b\u3089\u30af\u30a8\u30ea\u3092\u6539\u4fee\u3059\u308b\u5f62\u3067\u8aac\u660e\u3057\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n\n\n\n

\u30c7\u30fc\u30bf\u53d6\u5f97\u6642\u306bNULL\u304c\u767a\u751f\u3059\u308b\u30af\u30a8\u30ea<\/h2>\n\n\n\n

\u30c7\u30fc\u30bf\u53d6\u5f97\u6642\u306bNULL\u3092\u53d6\u5f97\u3059\u308b\u30af\u30a8\u30ea\u306f2\u7a2e\u985e\u5b58\u5728\u3057\u307e\u3059\u3002

1\u3064\u76ee\u306f\u3001\u30c7\u30fc\u30bf\u306bNULL\u304c\u5165\u3063\u3066\u3044\u308b\u30c6\u30fc\u30d6\u30eb\u304b\u3089\u30c7\u30fc\u30bf\u3092\u53d6\u5f97\u3059\u308b\u5834\u5408<\/span>\u30012\u3064\u76ee\u306fJOIN\u306b\u3088\u308b\u5916\u90e8\u7d50\u5408\u306e\u7d50\u679c\u3001NULL\u306e\u5217\u304c\u767a\u751f\u3057\u3066\u3057\u307e\u3046\u5834\u5408<\/span>\u3067\u3059\u3002

\u30c6\u30fc\u30d6\u30eb\u306e\u30c7\u30fc\u30bf\u306bNULL\u304c\u5165\u3063\u3066\u3044\u308b\u306e\u306f\u3088\u304f\u3042\u308b\u3053\u3068\u3067\u3001\u30c6\u30fc\u30d6\u30eb\u306e\u5217\u306bNULL\u3092\u8a31\u5bb9\u3059\u308b\u304b\u3069\u3046\u304b\u3092\u6307\u5b9a\u3057\u3066\u3001NULL\u3092\u8a31\u5bb9\u3057\u305f\u5834\u5408\u306f\u3001\u30c6\u30fc\u30d6\u30eb\u306e\u5217\u306e\u30c7\u30fc\u30bf\u306bNULL\u304c\u521d\u671f\u5024\u3067\u5165\u308a\u307e\u3059\u3002

\u57fa\u672c\u7684\u306b\u3059\u3079\u3066\u306e\u5217\u306bNULL\u3092\u8a31\u5bb9\u3057\u306a\u3044\u3068\u3044\u3046\u30b1\u30fc\u30b9\u306f\u5c11\u306a\u3044\u306e\u3067\u3001\u30c6\u30fc\u30d6\u30eb\u306b\u5165\u3063\u3066\u3044\u308b\u30c7\u30fc\u30bf\u306b\u306fNULL\u306e\u30c7\u30fc\u30bf\u304c\u5165\u3063\u3066\u3044\u308b\u3053\u3068\u306e\u65b9\u304c\u591a\u3044<\/span>\u3068\u601d\u3063\u3066\u304a\u3044\u305f\u65b9\u304c\u3044\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n\n\n\n

NULL\u3092\u53d6\u5f97\u3059\u308b\u30af\u30a8\u30ea\u306b\u3064\u3044\u3066<\/h2>\n\n\n\n

\u4eca\u56de\u306fJOIN\u3067\u30c6\u30fc\u30d6\u30eb\u3092\u7d50\u5408\u3057\u305f\u7d50\u679c\u3001NULL\u304c\u767a\u751f\u3057\u305f\u5834\u5408\u306bNULL\u30920\u3084\u7a7a\u6587\u5b57\u306b\u5909\u63db\u3059\u308b\u3053\u3068\u3092\u8003\u3048\u3066\u307f\u307e\u3059\u3002

\u4f8b\u3048\u3070\u3001\u524d\u56de\u306e\u8aac\u660e\u3067\u7528\u3044\u305f\u4ee5\u4e0b\u306e\u30af\u30a8\u30ea\u3092\u8003\u3048\u3066\u307f\u307e\u3059\u3002<\/p>\n\n\n\n

SELECT sales.date, item.item_code, sales.seq_no, item.price * sales.amount as sales_price\nFROM sales\nLEFT JOIN item \nON item.item_code = sales.item_code<\/code><\/pre><\/div>\n\n\n\n
\u3053\u308c\u3092\u5b9f\u884c\u3059\u308b\u3068\u3001\u4ee5\u4e0b\u306e\u7d50\u679c\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
NULL\u30920\u3084\u7a7a\u6587\u5b57\u306b\u5909\u63db\u3059\u308b\u5834\u5408\u306fCOALESCE\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002

COALESCE\uff08\uff1cNULL\u3092\u5909\u63db\u3057\u305f\u3044\u5217\u540d\uff1e,<NULL\u3092\u5909\u63db\u3059\u308b\u5024>\uff09<\/span><\/span>

\u3068\u3044\u3046\u66f8\u304d\u65b9\u3067\u3001NULL\u3092\u5909\u63db\u3059\u308b\u3053\u3068\u304c\u51fa\u6765\u307e\u3059\u3002

\u4f8b\u3048\u3070\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u30af\u30a8\u30ea\u3092\u66f8\u304d\u63db\u3048\u3066\u307f\u307e\u3059\u3002<\/p>\n\n\n\n
SELECT sales.date, COALESCE(item.item_code, '') AS item_code, sales.seq_no, \nCOALESCE(item.price, 0) * sales.amount as sales_price\nFROM sales\nLEFT JOIN item \nON item.item_code = sales.item_code<\/code><\/pre><\/div>\n\n\n\n
\u3053\u306e\u30af\u30a8\u30ea\u3067\u306f\u3001item\u30c6\u30fc\u30d6\u30eb\u3092\u5916\u90e8\u7d50\u5408\u3057\u305f\u969b\u306bitem_code\u304cNULL\u306e\u5834\u5408\u306f\u7a7a\u6587\u5b57\u306b\u3001price\u304cNULL\u306e\u5834\u5408\u306f0\u306b\u5909\u63db\u3059\u308b\u3068\u3044\u3046\u51e6\u7406\u3092\u884c\u3063\u3066\u3044\u307e\u3059\u3002

\u3053\u306e\u30af\u30a8\u30ea\u306e\u5b9f\u884c\u7d50\u679c\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
item_code\u6b04\u306eNULL\u304c\u6d88\u3048\u3066\u7a7a\u6587\u5b57\u306b\u306a\u3063\u305f\u3053\u3068\u3001sales_price\u6b04\u306eNULL\u304c\u6d88\u3048\u30660\u306b\u306a\u3063\u305f\u3053\u3068\u304c\u78ba\u8a8d\u3067\u304d\u307e\u3059\u3002

\u3053\u306e\u3088\u3046\u306b\u3001\u30af\u30a8\u30ea\u306e\u7d50\u679c\u306eNULL\u3092\u5909\u63db\u3057\u305f\u3044\u5834\u5408\u306f\u3001COALESCE\u3092\u4f7f\u3046\u3068NULL\u3092\u7a7a\u6587\u5b57\u30840\u306b\u5909\u63db\u3057\u3066\u3001\u30af\u30a8\u30ea\u306e\u53d6\u5f97\u7d50\u679c\u306bNULL\u3092\u6df7\u5165\u3055\u305b\u305a\u306b\u6e08\u307f\u307e\u3059\u3002<\/p>\n\n\n\n
NULL\u3092\u5909\u63db\u3059\u308bCOALESCE\u4ee5\u5916\u306e\u66f8\u304d\u65b9<\/h2>\n\n\n\n
NULL\u3092\u5909\u63db\u3059\u308b\u95a2\u6570\u306fSQL\u306e\u7a2e\u985e\u306b\u3088\u3063\u3066COALESCE\u4ee5\u5916\u306b\u3082\u7528\u610f\u3055\u308c\u3066\u3044\u308b\u3082\u306e\u304c\u3042\u308a\u307e\u3059\u3002

SQLServer\u3001MySQL\u3001Oracle\u3067\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306bNULL\u3092\u5909\u63db\u3059\u308b\u95a2\u6570\u304c\u7528\u610f\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n\n
SQLServer<\/td>ISNULL<\/td><\/tr>
MySQL<\/td>IFNULL<\/td><\/tr>
Oracle<\/td>NVL<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u69cb\u6587\u306fCOALESCE\u3068\u540c\u3058\u3067\u3001\u7b2c\u4e00\u5f15\u6570\u306bNULL\u3092\u5909\u63db\u3057\u305f\u3044\u5217\u540d\u3001\u7b2c\u4e8c\u5f15\u6570\u306bNULL\u3092\u5909\u63db\u3059\u308b\u5024\u3092\u8a2d\u5b9a\u3057\u307e\u3059\u3002

\u57fa\u672c\u7684\u306bCOALESCE\u3092\u4f7f\u3046\u3068\u3069\u306eSQL\u3067\u3082\u30a8\u30e9\u30fc\u306b\u306a\u3089\u305a\u306b\u5909\u63db\u3057\u3066\u304f\u308c\u307e\u3059\u304c\u3001\u958b\u767a\u306e\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u306b\u3088\u3063\u3066\u306fISNULL\u3084IFNULL\u306a\u3069\u3092\u4f7f\u3046\u65b9\u304c\u4e3b\u6d41\u306b\u306a\u3063\u3066\u3044\u308b\u30d7\u30ed\u30b0\u30e9\u30e0\u3082\u898b\u304b\u3051\u307e\u3059\u3002

\u306a\u306e\u3067\u3001\u305f\u3060COALESCE\u3092\u77e5\u3063\u3066\u304a\u3051\u3070\u3044\u3044\u3068\u3044\u3046\u308f\u3051\u3067\u306f\u306a\u304f\u3001\u30e1\u30f3\u30c6\u30ca\u30f3\u30b9\u3059\u308b\u30d7\u30ed\u30b0\u30e9\u30e0\u3084\u65b0\u898f\u3067\u958b\u767a\u3059\u308b\u30d7\u30ed\u30b0\u30e9\u30e0\u306eSQL\u306e\u66f8\u304d\u65b9\u306e\u30eb\u30fc\u30eb\u306b\u5f93\u3063\u3066\u3001\u67d4\u8edf\u306b\u4f7f\u3044\u5206\u3051\u308b\u3053\u3068\u304c\u91cd\u8981\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n
\u307e\u3068\u3081<\/h2>\n\n\n\n
\u4eca\u56de\u306f\u4ee5\u4e0b\u306e\u70b9\u306b\u3064\u3044\u3066\u8aac\u660e\u3057\u307e\u3057\u305f\u3002<\/p>\n\n\n\n
    \n
  1. NULL\u3092\u7a7a\u6587\u5b57\u30840\u306b\u5909\u63db\u3057\u305f\u3044\u5834\u5408\u306fCOALESCE\u3092\u4f7f\u3046<\/li>\n\n\n\n
  2. NULL\u3092\u7a7a\u6587\u5b57\u30840\u306b\u5909\u63db\u3059\u308b\u95a2\u6570\u306fCOALESCE\u4ee5\u5916\u306b\u3082\u3042\u308a\u3001\u958b\u767a\u3059\u308b\u30d7\u30ed\u30b0\u30e9\u30e0\u306b\u3088\u3063\u3066\u4f7f\u3044\u5206\u3051\u308b\u3053\u3068\u304c\u91cd\u8981<\/li>\n<\/ol>\n\n\n\n
    NULL\u3092\u7a7a\u6587\u5b57\u30840\u306b\u5909\u63db\u3059\u308b\u6a5f\u4f1a\u306f\u5b9f\u969b\u306e\u958b\u767a\u306e\u5834\u3067\u306f\u7d50\u69cb\u3042\u308b\u304b\u3068\u601d\u3044\u307e\u3059\u3002

    \u30d7\u30ed\u30b0\u30e9\u30e0\u5074\u3067NULL\u3092\u5236\u5fa1\u3059\u308b\u65b9\u6cd5\u3082\u3042\u308b\u306e\u3067\u3059\u304c\u3001SQL\u306b\u3088\u308a\u30c7\u30fc\u30bf\u3092\u53d6\u5f97\u3057\u305f\u6642\u306bNULL\u306e\u6df7\u5165\u3092\u9632\u304e\u305f\u3044\u5834\u5408\u306f\u3001\u4eca\u56de\u306e\u5185\u5bb9\u3092\u7406\u89e3\u3057\u3001\u304d\u3061\u3093\u3068\u5bfe\u51e6\u304c\u51fa\u6765\u308b\u3088\u3046\u306b\u3057\u3066\u304a\u304d\u305f\u3044\u3082\u306e\u3067\u3059\u3002<\/p>\n\n\n\n
    \u4eca\u56de\u306e\u8a18\u4e8b\u306f\u3053\u3053\u307e\u3067\u3068\u306a\u308a\u307e\u3059\u3002
    \u307e\u305f\u6b21\u306e\u8a18\u4e8b\u3067\u304a\u4f1a\u3044\u3057\u307e\u3057\u3087\u3046\u3002<\/span><\/p>\n\n\n\n
    <\/p>\n","protected":false},"excerpt":{"rendered":"
    \u4eca\u56de\u306fSQL\u3067NULL\u30920\u3084\u7a7a\u6587\u5b57\u306b\u5909\u63db\u3059\u308b\u65b9\u6cd5\u3092\u8aac\u660e\u3057\u307e\u3059\u3002 \u30d7\u30ed\u30b0\u30e9\u30e0\u3067\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u4e0a\u3067\u30c7\u30fc\u30bf\u53d6\u5f97\u306e\u30af\u30a8\u30ea\u3092\u5b9f\u884c\u3055\u305b\u3001\u5b9f\u884c\u7d50\u679c\u3092\u53d7\u3051\u53d6\u308b\u51e6\u7406\u3092\u66f8\u304f\u5834\u5408\u3001\u30af\u30a8\u30ea\u304c\u8fd4\u3059NULL\u3092\u305d\u306e\u307e\u307e\u4f7f\u3044\u305f\u304f\u306a\u3044\u3068\u3044\u3046\u306e\u306f\u3001\u307e\u3042\u307e\u3042\u826f<\/p>\n","protected":false},"author":2,"featured_media":359,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jin_ogp_image_url":"","_jin_last_featured_id":0,"footnotes":""},"categories":[23],"tags":[24,16],"class_list":["post-387","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-database","tag-24","tag-16"],"_links":{"self":[{"href":"https:\/\/se-pg-toolbox.com\/index.php?rest_route=\/wp\/v2\/posts\/387","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/se-pg-toolbox.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/se-pg-toolbox.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/se-pg-toolbox.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/se-pg-toolbox.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=387"}],"version-history":[{"count":4,"href":"https:\/\/se-pg-toolbox.com\/index.php?rest_route=\/wp\/v2\/posts\/387\/revisions"}],"predecessor-version":[{"id":395,"href":"https:\/\/se-pg-toolbox.com\/index.php?rest_route=\/wp\/v2\/posts\/387\/revisions\/395"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/se-pg-toolbox.com\/index.php?rest_route=\/wp\/v2\/media\/359"}],"wp:attachment":[{"href":"https:\/\/se-pg-toolbox.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=387"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/se-pg-toolbox.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=387"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/se-pg-toolbox.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=387"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}