{"id":178678,"date":"2024-11-08T19:58:17","date_gmt":"2024-11-08T11:58:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/178678\/"},"modified":"2024-11-08T19:58:18","modified_gmt":"2024-11-08T11:58:18","slug":"%e5%a6%82%e4%bd%95%e4%bf%ae%e5%be%a9postgresql%e9%8c%af%e8%aa%a4%e4%bb%a3%e7%a2%bc%ef%bc%9a22002-null_value_no_indicator_parameter%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/178678\/","title":{"rendered":"\u5982\u4f55\u4fee\u5fa9PostgreSQL\u932f\u8aa4\u4ee3\u78bc\uff1a22002 &#8211; null_value_no_indicator_parameter\uff1f"},"content":{"rendered":"<h1 id=\"%e5%a6%82%e4%bd%95%e4%bf%ae%e5%be%a9postgresql%e9%8c%af%e8%aa%a4%e4%bb%a3%e7%a2%bc%ef%bc%9a22002-null_value_no_indicator_parameter-dQTYbLhFsA\">\u5982\u4f55\u4fee\u5fa9PostgreSQL\u932f\u8aa4\u4ee3\u78bc\uff1a22002 &#8211; null_value_no_indicator_parameter<\/h1>\n<p>\u5728\u4f7f\u7528PostgreSQL\u6578\u64da\u5eab\u6642\uff0c\u958b\u767c\u8005\u53ef\u80fd\u6703\u9047\u5230\u5404\u7a2e\u932f\u8aa4\u4ee3\u78bc\uff0c\u5176\u4e2d\u4e4b\u4e00\u662f22002 &#8211; null_value_no_indicator_parameter\u3002\u9019\u500b\u932f\u8aa4\u901a\u5e38\u51fa\u73fe\u5728\u5617\u8a66\u5f9e\u6578\u64da\u5eab\u4e2d\u6aa2\u7d22\u6578\u64da\u6642\uff0c\u7279\u5225\u662f\u7576\u6d89\u53ca\u5230NULL\u503c\u7684\u60c5\u6cc1\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e\u9019\u500b\u932f\u8aa4\u7684\u539f\u56e0\u53ca\u5176\u89e3\u6c7a\u65b9\u6848\u3002<\/p>\n<h2 id=\"%e9%8c%af%e8%aa%a4%e4%bb%a3%e7%a2%bc22002%e7%9a%84%e8%83%8c%e6%99%af-dQTYbLhFsA\">\u932f\u8aa4\u4ee3\u78bc22002\u7684\u80cc\u666f<\/h2>\n<p>PostgreSQL\u7684\u932f\u8aa4\u4ee3\u78bc22002\u8868\u793a\u5728\u8655\u7406NULL\u503c\u6642\u51fa\u73fe\u4e86\u554f\u984c\u3002\u9019\u901a\u5e38\u767c\u751f\u5728\u4f7f\u7528\u67d0\u4e9b\u51fd\u6578\u6216\u67e5\u8a62\u6642\uff0c\u9019\u4e9b\u51fd\u6578\u6216\u67e5\u8a62\u671f\u671b\u63a5\u6536\u4e00\u500b\u6307\u793aNULL\u503c\u7684\u53c3\u6578\uff0c\u4f46\u537b\u6c92\u6709\u63d0\u4f9b\u3002\u9019\u53ef\u80fd\u5c0e\u81f4\u6578\u64da\u5eab\u7121\u6cd5\u6b63\u78ba\u57f7\u884c\u67e5\u8a62\uff0c\u5f9e\u800c\u8fd4\u56de\u932f\u8aa4\u3002<\/p>\n<h2 id=\"%e5%b8%b8%e8%a6%8b%e5%8e%9f%e5%9b%a0-dQTYbLhFsA\">\u5e38\u898b\u539f\u56e0<\/h2>\n<ul>\n<li><strong>\u7f3a\u5c11NULL\u6307\u793a\u5668\uff1a<\/strong>\u7576\u4f7f\u7528C\u8a9e\u8a00\u6216\u5176\u4ed6\u8a9e\u8a00\u7684API\u8207PostgreSQL\u4ea4\u4e92\u6642\uff0c\u958b\u767c\u8005\u9700\u8981\u63d0\u4f9bNULL\u6307\u793a\u5668\u3002\u5982\u679c\u672a\u6b63\u78ba\u8a2d\u7f6e\uff0c\u5247\u6703\u5c0e\u81f4\u6b64\u932f\u8aa4\u3002<\/li>\n<li><strong>\u4e0d\u6b63\u78ba\u7684SQL\u67e5\u8a62\uff1a<\/strong>\u67d0\u4e9bSQL\u67e5\u8a62\u5728\u8655\u7406NULL\u503c\u6642\u53ef\u80fd\u6703\u51fa\u73fe\u554f\u984c\uff0c\u7279\u5225\u662f\u7576\u4f7f\u7528\u805a\u5408\u51fd\u6578\u6216\u5b50\u67e5\u8a62\u6642\u3002<\/li>\n<li><strong>\u6578\u64da\u985e\u578b\u4e0d\u5339\u914d\uff1a<\/strong>\u5982\u679c\u67e5\u8a62\u4e2d\u7684\u6578\u64da\u985e\u578b\u8207\u6578\u64da\u5eab\u4e2d\u5b9a\u7fa9\u7684\u985e\u578b\u4e0d\u5339\u914d\uff0c\u5247\u53ef\u80fd\u6703\u5c0e\u81f4\u6b64\u932f\u8aa4\u3002<\/li>\n<\/ul>\n<h2 id=\"%e5%a6%82%e4%bd%95%e4%bf%ae%e5%be%a9%e9%8c%af%e8%aa%a4-dQTYbLhFsA\">\u5982\u4f55\u4fee\u5fa9\u932f\u8aa4<\/h2>\n<p>\u4fee\u5fa9PostgreSQL\u932f\u8aa4\u4ee3\u78bc22002\u7684\u904e\u7a0b\u901a\u5e38\u6d89\u53ca\u4ee5\u4e0b\u5e7e\u500b\u6b65\u9a5f\uff1a<\/p>\n<h3 id=\"1-%e6%aa%a2%e6%9f%a5sql%e6%9f%a5%e8%a9%a2-dQTYbLhFsA\">1. \u6aa2\u67e5SQL\u67e5\u8a62<\/h3>\n<p>\u9996\u5148\uff0c\u6aa2\u67e5\u5f15\u767c\u932f\u8aa4\u7684SQL\u67e5\u8a62\u3002\u78ba\u4fdd\u6240\u6709\u7684NULL\u503c\u90fd\u6b63\u78ba\u8655\u7406\u3002\u4f8b\u5982\uff0c\u4f7f\u7528COALESCE\u51fd\u6578\u4f86\u8655\u7406\u53ef\u80fd\u7684NULL\u503c\uff1a<\/p>\n<pre><code>SELECT COALESCE(column_name, 'default_value') FROM table_name;<\/code><\/pre>\n<h3 id=\"2-%e8%a8%ad%e7%bd%aenull%e6%8c%87%e7%a4%ba%e5%99%a8-dQTYbLhFsA\">2. \u8a2d\u7f6eNULL\u6307\u793a\u5668<\/h3>\n<p>\u5982\u679c\u60a8\u4f7f\u7528\u7684\u662fC\u8a9e\u8a00\u6216\u5176\u4ed6\u8a9e\u8a00\u7684API\uff0c\u8acb\u78ba\u4fdd\u5728\u50b3\u905e\u53c3\u6578\u6642\u8a2d\u7f6eNULL\u6307\u793a\u5668\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>int param_is_null = 0; \/\/ 0\u8868\u793a\u4e0d\u662fNULL\nPQexecParams(conn, \"SELECT * FROM table_name WHERE column_name = $1\", 1, &amp;param_value, &amp;param_is_null);<\/code><\/pre>\n<h3 id=\"3-%e6%aa%a2%e6%9f%a5%e6%95%b8%e6%93%9a%e9%a1%9e%e5%9e%8b-dQTYbLhFsA\">3. \u6aa2\u67e5\u6578\u64da\u985e\u578b<\/h3>\n<p>\u78ba\u4fdd\u67e5\u8a62\u4e2d\u4f7f\u7528\u7684\u6578\u64da\u985e\u578b\u8207\u6578\u64da\u5eab\u4e2d\u5b9a\u7fa9\u7684\u985e\u578b\u76f8\u5339\u914d\u3002\u5982\u679c\u6709\u4e0d\u5339\u914d\u7684\u60c5\u6cc1\uff0c\u8acb\u9032\u884c\u76f8\u61c9\u7684\u8abf\u6574\u3002<\/p>\n<h3 id=\"4-%e4%bd%bf%e7%94%a8explain%e5%88%86%e6%9e%90%e6%9f%a5%e8%a9%a2-dQTYbLhFsA\">4. \u4f7f\u7528EXPLAIN\u5206\u6790\u67e5\u8a62<\/h3>\n<p>\u4f7f\u7528EXPLAIN\u547d\u4ee4\u4f86\u5206\u6790\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\uff0c\u9019\u53ef\u4ee5\u5e6b\u52a9\u60a8\u627e\u51fa\u554f\u984c\u6240\u5728\uff1a<\/p>\n<pre><code>EXPLAIN SELECT * FROM table_name WHERE column_name = $1;<\/code><\/pre>\n<h2 id=\"%e7%b5%90%e8%ab%96-dQTYbLhFsA\">\u7d50\u8ad6<\/h2>\n<p>PostgreSQL\u932f\u8aa4\u4ee3\u78bc22002 &#8211; null_value_no_indicator_parameter\u662f\u4e00\u500b\u5e38\u898b\u7684\u554f\u984c\uff0c\u901a\u5e38\u8207NULL\u503c\u7684\u8655\u7406\u6709\u95dc\u3002\u901a\u904e\u6aa2\u67e5SQL\u67e5\u8a62\u3001\u8a2d\u7f6eNULL\u6307\u793a\u5668\u3001\u78ba\u4fdd\u6578\u64da\u985e\u578b\u5339\u914d\u4ee5\u53ca\u4f7f\u7528EXPLAIN\u5206\u6790\u67e5\u8a62\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u6709\u6548\u5730\u89e3\u6c7a\u9019\u500b\u554f\u984c\u3002<\/p>\n<p>\u5982\u679c\u60a8\u5728\u5c0b\u627e\u9ad8\u6548\u7684\u89e3\u6c7a\u65b9\u6848\u4f86\u904b\u884cPostgreSQL\u6578\u64da\u5eab\uff0c\u8003\u616e\u4f7f\u7528<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u670d\u52d9\uff0c\u9019\u5c07\u70ba\u60a8\u7684\u61c9\u7528\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3\u5982\u4f55\u4fee\u5fa9PostgreSQL\u932f\u8aa4\u4ee3\u78bc22002\uff0c\u89e3\u6c7anull_value_no_indicator_parameter\u554f\u984c\uff0c\u63d0\u5347\u6578\u64da\u5eab\u6027\u80fd\u3002<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-178678","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/178678","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=178678"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/178678\/revisions"}],"predecessor-version":[{"id":178679,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/178678\/revisions\/178679"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=178678"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=178678"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=178678"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}