{"id":3152,"date":"2019-04-17T16:24:46","date_gmt":"2019-04-17T08:24:46","guid":{"rendered":"https:\/\/damogame.cn\/wordpress\/?p=3152"},"modified":"2019-04-17T16:24:46","modified_gmt":"2019-04-17T08:24:46","slug":"go-database-sql-%e6%95%99%e7%a8%8b","status":"publish","type":"post","link":"https:\/\/i007.cc\/wordpress\/archives\/3152","title":{"rendered":"Go database\/sql \u6559\u7a0b"},"content":{"rendered":"<p class=\"blog-summary\"><em>\u6458\u8981\uff1a<\/em>\u00a0Go\u4f7f\u7528SQL\u4e0e\u7c7bSQL\u6570\u636e\u5e93\u7684\u60ef\u4f8b\u662f\u901a\u8fc7\u6807\u51c6\u5e93[database\/sql](http:\/\/golang.org\/pkg\/database\/sql\/)\u3002\u8fd9\u662f\u4e00\u4e2a\u5bf9\u5173\u7cfb\u578b\u6570\u636e\u5e93\u7684\u901a\u7528\u62bd\u8c61\uff0c\u5b83\u63d0\u4f9b\u4e86\u6807\u51c6\u7684\u3001\u8f7b\u91cf\u7684\u3001\u9762\u5411\u884c\u7684\u63a5\u53e3\u3002\u4e0d\u8fc7`database\/sql`\u7684\u5305\u6587\u6863\u53ea\u8bb2\u5b83\u505a\u4e86\u4ec0\u4e48\uff0c\u5374\u5bf9\u5982\u4f55\u4f7f\u7528\u53ea\u5b57\u672a\u63d0\u3002\u5feb\u901f\u6307\u5357\u8fdc\u6bd4\u5806\u780c\u4e8b\u5b9e\u6709\u7528\uff0c\u672c\u6587\u8bb2\u8ff0\u4e86`database\/sql`\u7684\u4f7f\u7528\u65b9\u6cd5\u53ca\u5176\u6ce8\u610f\u4e8b\u9879\u3002<\/p>\n<div class=\"content-detail markdown-body\">\n<p>Go\u4f7f\u7528SQL\u4e0e\u7c7bSQL\u6570\u636e\u5e93\u7684\u60ef\u4f8b\u662f\u901a\u8fc7\u6807\u51c6\u5e93<a href=\"http:\/\/golang.org\/pkg\/database\/sql\/\">database\/sql<\/a>\u3002\u8fd9\u662f\u4e00\u4e2a\u5bf9\u5173\u7cfb\u578b\u6570\u636e\u5e93\u7684\u901a\u7528\u62bd\u8c61\uff0c\u5b83\u63d0\u4f9b\u4e86\u6807\u51c6\u7684\u3001\u8f7b\u91cf\u7684\u3001\u9762\u5411\u884c\u7684\u63a5\u53e3\u3002\u4e0d\u8fc7<code>database\/sql<\/code>\u7684\u5305\u6587\u6863\u53ea\u8bb2\u5b83\u505a\u4e86\u4ec0\u4e48\uff0c\u5374\u5bf9\u5982\u4f55\u4f7f\u7528\u53ea\u5b57\u672a\u63d0\u3002\u5feb\u901f\u6307\u5357\u8fdc\u6bd4\u5806\u780c\u4e8b\u5b9e\u6709\u7528\uff0c\u672c\u6587\u8bb2\u8ff0\u4e86<code>database\/sql<\/code>\u7684\u4f7f\u7528\u65b9\u6cd5\u53ca\u5176\u6ce8\u610f\u4e8b\u9879\u3002<\/p>\n<h2 id=\"1\">1. \u9876\u5c42\u62bd\u8c61<\/h2>\n<p>\u5728Go\u4e2d\u8bbf\u95ee\u6570\u636e\u5e93\u9700\u8981\u7528\u5230<code>sql.DB<\/code>\u63a5\u53e3\uff1a\u5b83\u53ef\u4ee5\u521b\u5efa\u8bed\u53e5(statement)\u548c\u4e8b\u52a1(transaction)\uff0c\u6267\u884c\u67e5\u8be2\uff0c\u83b7\u53d6\u7ed3\u679c\u3002<\/p>\n<p><code>sql.DB<\/code>\u5e76\u4e0d\u662f\u6570\u636e\u5e93\u8fde\u63a5\uff0c\u4e5f\u5e76\u672a\u5728\u6982\u5ff5\u4e0a\u6620\u5c04\u5230\u7279\u5b9a\u7684\u6570\u636e\u5e93(Database)\u6216\u6a21\u5f0f(schema)\u3002\u5b83\u53ea\u662f\u4e00\u4e2a\u62bd\u8c61\u7684\u63a5\u53e3\uff0c\u4e0d\u540c\u7684\u5177\u4f53\u9a71\u52a8\u6709\u7740\u4e0d\u540c\u7684\u5b9e\u73b0\u65b9\u5f0f\u3002\u901a\u5e38\u800c\u8a00\uff0c<code>sql.DB<\/code>\u4f1a\u5904\u7406\u4e00\u4e9b\u91cd\u8981\u800c\u9ebb\u70e6\u7684\u4e8b\u60c5\uff0c\u4f8b\u5982\u64cd\u4f5c\u5177\u4f53\u7684\u9a71\u52a8\u6253\u5f00\/\u5173\u95ed\u5b9e\u9645\u5e95\u5c42\u6570\u636e\u5e93\u7684\u8fde\u63a5\uff0c\u6309\u9700\u7ba1\u7406\u8fde\u63a5\u6c60\u3002<\/p>\n<p><code>sql.DB<\/code>\u8fd9\u4e00\u62bd\u8c61\u8ba9\u7528\u6237\u4e0d\u5fc5\u8003\u8651\u5982\u4f55\u7ba1\u7406\u5e76\u53d1\u8bbf\u95ee\u5e95\u5c42\u6570\u636e\u5e93\u7684\u95ee\u9898\u3002\u5f53\u4e00\u4e2a\u8fde\u63a5\u5728\u6267\u884c\u4efb\u52a1\u65f6\u4f1a\u88ab\u6807\u8bb0\u4e3a\u6b63\u5728\u4f7f\u7528\u3002\u7528\u5b8c\u4e4b\u540e\u4f1a\u653e\u56de\u8fde\u63a5\u6c60\u4e2d\u3002\u4e0d\u8fc7\u7528\u6237\u5982\u679c\u7528\u5b8c\u8fde\u63a5\u540e\u5fd8\u8bb0\u91ca\u653e\uff0c\u5c31\u4f1a\u4ea7\u751f\u5927\u91cf\u7684\u8fde\u63a5\uff0c\u6781\u53ef\u80fd\u5bfc\u81f4\u8d44\u6e90\u8017\u5c3d\uff08\u5efa\u7acb\u592a\u591a\u8fde\u63a5\uff0c\u6253\u5f00\u592a\u591a\u6587\u4ef6\uff0c\u7f3a\u5c11\u53ef\u7528\u7f51\u7edc\u7aef\u53e3\uff09\u3002<\/p>\n<h2 id=\"2\">2. \u5bfc\u5165\u9a71\u52a8<\/h2>\n<p>\u4f7f\u7528\u6570\u636e\u5e93\u65f6\uff0c\u9664\u4e86<code>database\/sql<\/code>\u5305\u672c\u8eab\uff0c\u8fd8\u9700\u8981\u5f15\u5165\u60f3\u4f7f\u7528\u7684\u7279\u5b9a\u6570\u636e\u5e93\u9a71\u52a8\u3002<\/p>\n<p>\u5c3d\u7ba1\u6709\u65f6\u5019\u4e00\u4e9b\u6570\u636e\u5e93\u7279\u6709\u7684\u529f\u80fd\u5fc5\u9700\u901a\u8fc7\u9a71\u52a8\u7684Ad Hoc\u63a5\u53e3\u6765\u5b9e\u73b0\uff0c\u4f46\u901a\u5e38\u53ea\u8981\u6709\u53ef\u80fd\uff0c\u8fd8\u662f\u5e94\u5f53\u5c3d\u91cf\u53ea\u7528<code>database\/sql<\/code>\u4e2d\u5b9a\u4e49\u7684\u7c7b\u578b\u3002\u8fd9\u53ef\u4ee5\u51cf\u5c0f\u7528\u6237\u4ee3\u7801\u4e0e\u9a71\u52a8\u7684\u8026\u5408\uff0c\u4f7f\u5207\u6362\u9a71\u52a8\u65f6\u4ee3\u7801\u6539\u52a8\u6700\u5c0f\u5316\uff0c\u4e5f\u5c3d\u53ef\u80fd\u5730\u4f7f\u7528\u6237\u9075\u5faaGo\u7684\u60ef\u7528\u6cd5\u3002\u672c\u6587\u4f7f\u7528PostgreSQL\u4e3a\u4f8b\uff0cPostgreSQL\u7684\u8457\u540d\u7684\u9a71\u52a8\u6709\uff1a<\/p>\n<ul>\n<li><a href=\"https:\/\/github.com\/lib\/pq\"><code>github.com\/lib\/pq<\/code><\/a><\/li>\n<li><a href=\"https:\/\/github.com\/go-pg\/pg\"><code>github.com\/go-pg\/pg<\/code><\/a><\/li>\n<li><a href=\"https:\/\/yq.aliyun.com\/articles\/%5B\"><code>github.com\/jackc\/pgx<\/code><\/a>\u3002<\/li>\n<\/ul>\n<p>\u8fd9\u91cc\u4ee5<code>pgx<\/code>\u4e3a\u4f8b\uff0c\u5b83\u6027\u80fd\u8868\u73b0\u4e0d\u4fd7\uff0c\u5e76\u5bf9PostgreSQL\u8bf8\u591a\u7279\u6027\u4e0e\u7c7b\u578b\u6709\u7740\u826f\u597d\u7684\u652f\u6301\u3002\u65e2\u53ef\u4f7f\u7528Ad-Hoc API\uff0c\u4e5f\u63d0\u4f9b\u4e86\u6807\u51c6\u6570\u636e\u5e93\u63a5\u53e3\u7684\u5b9e\u73b0\uff1a<code>github.com\/jackc\/pgx\/stdlib<\/code>\u3002<\/p>\n<pre><code class=\"hljs java\"><span class=\"hljs-keyword\">import<\/span> (\r\n    <span class=\"hljs-string\">\"database\/sql\"<\/span>\r\n    _ <span class=\"hljs-string\">\"github.com\/jackx\/pgx\/stdlib\"<\/span>\r\n)\r\n<\/code><\/pre>\n<p>\u4f7f\u7528<code>_<\/code>\u522b\u540d\u6765\u533f\u540d\u5bfc\u5165\u9a71\u52a8\uff0c\u9a71\u52a8\u7684\u5bfc\u51fa\u540d\u5b57\u4e0d\u4f1a\u51fa\u73b0\u5728\u5f53\u524d\u4f5c\u7528\u57df\u4e2d\u3002\u5bfc\u5165\u65f6\uff0c\u9a71\u52a8\u7684\u521d\u59cb\u5316\u51fd\u6570\u4f1a\u8c03\u7528<code>sql.Register<\/code>\u5c06\u81ea\u5df1\u6ce8\u518c\u5728<code>database\/sql<\/code>\u5305\u7684\u5168\u5c40\u53d8\u91cf<code>sql.drivers<\/code>\u4e2d\uff0c\u4ee5\u4fbf\u4ee5\u540e\u901a\u8fc7<code>sql.Open<\/code>\u8bbf\u95ee\u3002<\/p>\n<h2 id=\"3\">3. \u8bbf\u95ee\u6570\u636e<\/h2>\n<p>\u52a0\u8f7d\u9a71\u52a8\u5305\u540e\uff0c\u9700\u8981\u4f7f\u7528<code>sql.Open()<\/code>\u6765\u521b\u5efa<code>sql.DB<\/code>\uff1a<\/p>\n<pre><code class=\"hljs cpp\"><span class=\"hljs-function\">func <span class=\"hljs-title\">main<\/span><span class=\"hljs-params\">()<\/span> <\/span>{\r\n    db, err := sql.Open(<span class=\"hljs-string\">\"pgx\"<\/span>,<span class=\"hljs-string\">\"postgres:\/\/localhost:5432\/postgres\"<\/span>)\r\n    <span class=\"hljs-keyword\">if<\/span> err != nil {\r\n        <span class=\"hljs-built_in\">log<\/span>.Fatal(err)\r\n    }\r\n    defer db.Close()\r\n}\r\n<\/code><\/pre>\n<p><code>sql.Open<\/code>\u6709\u4e24\u4e2a\u53c2\u6570\uff1a<\/p>\n<ul>\n<li>\u7b2c\u4e00\u4e2a\u53c2\u6570\u662f\u9a71\u52a8\u540d\u79f0\uff0c\u5b57\u7b26\u4e32\u7c7b\u578b\u3002\u4e3a\u907f\u514d\u6df7\u6dc6\uff0c\u4e00\u822c\u4e0e\u5305\u540d\u76f8\u540c\uff0c\u8fd9\u91cc\u662f<code>pgx<\/code>\u3002<\/li>\n<li>\u7b2c\u4e8c\u4e2a\u53c2\u6570\u4e5f\u662f\u5b57\u7b26\u4e32\uff0c\u5185\u5bb9\u4f9d\u8d56\u4e8e\u7279\u5b9a\u9a71\u52a8\u7684\u8bed\u6cd5\u3002\u901a\u5e38\u662fURL\u7684\u5f62\u5f0f\uff0c\u4f8b\u5982<code>postgres:\/\/localhost:5432<\/code>\u3002<\/li>\n<li>\u7edd\u5927\u591a\u6570\u60c5\u51b5\u4e0b\u90fd\u5e94\u5f53\u68c0\u67e5<code>database\/sql<\/code>\u64cd\u4f5c\u6240\u8fd4\u56de\u7684\u9519\u8bef\u3002<\/li>\n<li>\u4e00\u822c\u800c\u8a00\uff0c\u7a0b\u5e8f\u9700\u8981\u5728\u9000\u51fa\u65f6\u901a\u8fc7<code>sql.DB<\/code>\u7684<code>Close()<\/code>\u65b9\u6cd5\u91ca\u653e\u6570\u636e\u5e93\u8fde\u63a5\u8d44\u6e90\u3002\u5982\u679c\u5176\u751f\u547d\u5468\u671f\u4e0d\u8d85\u8fc7\u51fd\u6570\u7684\u8303\u56f4\uff0c\u5219\u5e94\u5f53\u4f7f\u7528<code>defer db.Close()<\/code><\/li>\n<\/ul>\n<p>\u6267\u884c<code>sql.Open()<\/code>\u5e76\u672a\u5b9e\u9645\u5efa\u7acb\u8d77\u5230\u6570\u636e\u5e93\u7684\u8fde\u63a5\uff0c\u4e5f\u4e0d\u4f1a\u9a8c\u8bc1\u9a71\u52a8\u53c2\u6570\u3002\u7b2c\u4e00\u4e2a\u5b9e\u9645\u7684\u8fde\u63a5\u4f1a\u60f0\u6027\u6c42\u503c\uff0c\u5ef6\u8fdf\u5230\u7b2c\u4e00\u6b21\u9700\u8981\u65f6\u5efa\u7acb\u3002\u7528\u6237\u5e94\u8be5\u901a\u8fc7<code>db.Ping()<\/code>\u6765\u68c0\u67e5\u6570\u636e\u5e93\u662f\u5426\u5b9e\u9645\u53ef\u7528\u3002<\/p>\n<pre><code class=\"go hljs ruby\"><span class=\"hljs-keyword\">if<\/span> err = db.Ping(); err != <span class=\"hljs-literal\">nil<\/span> {\r\n    <span class=\"hljs-regexp\">\/\/<\/span> <span class=\"hljs-keyword\">do<\/span> something about db error\r\n}<\/code><\/pre>\n<p><code>sql.DB<\/code>\u5bf9\u8c61\u662f\u4e3a\u4e86\u957f\u8fde\u63a5\u800c\u8bbe\u8ba1\u7684\uff0c\u4e0d\u8981\u9891\u7e41<code>Open()<\/code>\u548c<code>Close()<\/code>\u6570\u636e\u5e93\u3002\u800c\u5e94\u8be5\u4e3a\u6bcf\u4e2a\u5f85\u8bbf\u95ee\u7684\u6570\u636e\u5e93\u521b\u5efa<strong>\u4e00\u4e2a<\/strong><code>sql.DB<\/code>\u5b9e\u4f8b\uff0c\u5e76\u5728\u7528\u5b8c\u524d\u4e00\u76f4\u4fdd\u7559\u5b83\u3002\u9700\u8981\u65f6\u53ef\u5c06\u5176\u4f5c\u4e3a\u53c2\u6570\u4f20\u9012\uff0c\u6216\u6ce8\u518c\u4e3a\u5168\u5c40\u5bf9\u8c61\u3002<\/p>\n<p>\u5982\u679c\u6ca1\u6709\u6309\u7167<code>database\/sql<\/code>\u8bbe\u8ba1\u7684\u610f\u56fe\uff0c\u4e0d\u628a<code>sql.DB<\/code>\u5f53\u6210\u957f\u671f\u5bf9\u8c61\u6765\u7528\u800c\u9891\u7e41\u5f00\u5173\u542f\u505c\uff0c\u5c31\u53ef\u80fd\u906d\u9047\u5404\u5f0f\u5404\u6837\u7684\u9519\u8bef\uff1a\u65e0\u6cd5\u590d\u7528\u548c\u5171\u4eab\u8fde\u63a5\uff0c\u8017\u5c3d\u7f51\u7edc\u8d44\u6e90\uff0c\u7531\u4e8eTCP\u8fde\u63a5\u4fdd\u6301\u5728<code>TIME_WAIT<\/code>\u72b6\u6001\u800c\u95f4\u65ad\u6027\u7684\u5931\u8d25\u7b49\u2026\u2026<\/p>\n<h2 id=\"4\">4. \u83b7\u53d6\u7ed3\u679c<\/h2>\n<p>\u6709\u4e86<code>sql.DB<\/code>\u5b9e\u4f8b\u4e4b\u540e\u5c31\u53ef\u4ee5\u5f00\u59cb\u6267\u884c\u67e5\u8be2\u8bed\u53e5\u4e86\u3002<\/p>\n<p>Go\u5c06\u6570\u636e\u5e93\u64cd\u4f5c\u5206\u4e3a\u4e24\u7c7b\uff1a<code>Query<\/code>\u4e0e<code>Exec<\/code>\u3002\u4e24\u8005\u7684\u533a\u522b\u5728\u4e8e\u524d\u8005\u4f1a\u8fd4\u56de\u7ed3\u679c\uff0c\u800c\u540e\u8005\u4e0d\u4f1a\u3002<\/p>\n<ul>\n<li><code>Query<\/code>\u8868\u793a\u67e5\u8be2\uff0c\u5b83\u4f1a\u4ece\u6570\u636e\u5e93\u83b7\u53d6\u67e5\u8be2\u7ed3\u679c\uff08\u4e00\u7cfb\u5217\u884c\uff0c\u53ef\u80fd\u4e3a\u7a7a\uff09\u3002<\/li>\n<li><code>Exec<\/code>\u8868\u793a\u6267\u884c\u8bed\u53e5\uff0c\u5b83\u4e0d\u4f1a\u8fd4\u56de\u884c\u3002<\/li>\n<\/ul>\n<p>\u6b64\u5916\u8fd8\u6709\u4e24\u79cd\u5e38\u89c1\u7684\u6570\u636e\u5e93\u64cd\u4f5c\u6a21\u5f0f\uff1a<\/p>\n<ul>\n<li><code>QueryRow<\/code>\u8868\u793a\u53ea\u8fd4\u56de\u4e00\u884c\u7684\u67e5\u8be2\uff0c\u4f5c\u4e3a<code>Query<\/code>\u7684\u4e00\u4e2a\u5e38\u89c1\u7279\u4f8b\u3002<\/li>\n<li><code>Prepare<\/code>\u8868\u793a\u51c6\u5907\u4e00\u4e2a\u9700\u8981\u591a\u6b21\u4f7f\u7528\u7684\u8bed\u53e5\uff0c\u4f9b\u540e\u7eed\u6267\u884c\u7528\u3002<\/li>\n<\/ul>\n<h3 id=\"5\">4.1 \u83b7\u53d6\u6570\u636e<\/h3>\n<p>\u8ba9\u6211\u4eec\u770b\u4e00\u4e2a\u5982\u4f55\u67e5\u8be2\u6570\u636e\u5e93\u5e76\u4e14\u5904\u7406\u7ed3\u679c\u7684\u4f8b\u5b50\uff1a\u5229\u7528\u6570\u636e\u5e93\u8ba1\u7b97\u4ece1\u523010\u7684\u81ea\u7136\u6570\u4e4b\u548c\u3002<\/p>\n<pre><code class=\"go hljs objectivec\">func example() {\r\n    var sum, n int32\r\n\r\n    <span class=\"hljs-comment\">\/\/ invoke query<\/span>\r\n    rows, err := db.Query(<span class=\"hljs-string\">\"SELECT generate_series(1,$1)\"<\/span>, <span class=\"hljs-number\">10<\/span>)\r\n    <span class=\"hljs-comment\">\/\/ handle query error<\/span>\r\n    <span class=\"hljs-keyword\">if<\/span> err != <span class=\"hljs-literal\">nil<\/span> {\r\n        fmt.Println(err)\r\n    }\r\n    <span class=\"hljs-comment\">\/\/ defer close result set<\/span>\r\n    defer rows.Close()\r\n\r\n    <span class=\"hljs-comment\">\/\/ Iter results<\/span>\r\n    <span class=\"hljs-keyword\">for<\/span> rows.Next() {\r\n        <span class=\"hljs-keyword\">if<\/span> err = rows.Scan(&amp;n); err != <span class=\"hljs-literal\">nil<\/span> {\r\n            fmt.Println(err)    <span class=\"hljs-comment\">\/\/ Handle scan error<\/span>\r\n        }\r\n        sum += n                <span class=\"hljs-comment\">\/\/ Use result<\/span>\r\n    }\r\n\r\n    <span class=\"hljs-comment\">\/\/ check iteration error<\/span>\r\n    <span class=\"hljs-keyword\">if<\/span> rows.Err() != <span class=\"hljs-literal\">nil<\/span> {\r\n        fmt.Println(err)\r\n    }\r\n\r\n    fmt.Println(sum)\r\n}<\/code><\/pre>\n<p>\u6574\u4f53\u5de5\u4f5c\u6d41\u7a0b\u5982\u4e0b\uff1a<\/p>\n<ol>\n<li>\u4f7f\u7528<code>db.Query()<\/code>\u6765\u53d1\u9001\u67e5\u8be2\u5230\u6570\u636e\u5e93\uff0c\u83b7\u53d6\u7ed3\u679c\u96c6<code>Rows<\/code>\uff0c\u5e76\u68c0\u67e5\u9519\u8bef\u3002<\/li>\n<li>\u4f7f\u7528<code>rows.Next()<\/code>\u4f5c\u4e3a\u5faa\u73af\u6761\u4ef6\uff0c\u8fed\u4ee3\u8bfb\u53d6\u7ed3\u679c\u96c6\u3002<\/li>\n<li>\u4f7f\u7528<code>rows.Scan<\/code>\u4ece\u7ed3\u679c\u96c6\u4e2d\u83b7\u53d6\u4e00\u884c\u7ed3\u679c\u3002<\/li>\n<li>\u4f7f\u7528<code>rows.Err()<\/code>\u5728\u9000\u51fa\u8fed\u4ee3\u540e\u68c0\u67e5\u9519\u8bef\u3002<\/li>\n<li>\u4f7f\u7528<code>rows.Close()<\/code>\u5173\u95ed\u7ed3\u679c\u96c6\uff0c\u91ca\u653e\u8fde\u63a5\u3002<\/li>\n<\/ol>\n<p>\u4e00\u4e9b\u9700\u8981\u8be6\u7ec6\u8bf4\u660e\u7684\u5730\u65b9\uff1a<\/p>\n<ol>\n<li><code>db.Query<\/code>\u4f1a\u8fd4\u56de\u7ed3\u679c\u96c6<code>*Rows<\/code>\u548c\u9519\u8bef\u3002\u6bcf\u4e2a\u9a71\u52a8\u8fd4\u56de\u7684\u9519\u8bef\u90fd\u4e0d\u4e00\u6837\uff0c\u7528\u9519\u8bef\u5b57\u7b26\u4e32\u6765\u5224\u65ad\u9519\u8bef\u7c7b\u578b\u5e76\u4e0d\u662f\u660e\u667a\u7684\u505a\u6cd5\uff0c\u66f4\u597d\u7684\u65b9\u6cd5\u662f\u5bf9\u62bd\u8c61\u7684\u9519\u8bef\u505a<code>Type Assertion<\/code>\uff0c\u5229\u7528\u9a71\u52a8\u63d0\u4f9b\u7684\u66f4\u5177\u4f53\u7684\u4fe1\u606f\u6765\u5904\u7406\u9519\u8bef\u3002\u5f53\u7136\u7c7b\u578b\u65ad\u8a00\u4e5f\u53ef\u80fd\u4ea7\u751f\u9519\u8bef\uff0c\u8fd9\u4e5f\u662f\u9700\u8981\u5904\u7406\u7684\u3002\n<pre><code class=\"go hljs python\"><span class=\"hljs-keyword\">if<\/span> err.(pgx.PgError).Code == <span class=\"hljs-string\">\"0A000\"<\/span> {\r\n    \/\/ Do something <span class=\"hljs-keyword\">with<\/span> that type <span class=\"hljs-keyword\">or<\/span> error\r\n}<\/code><\/pre>\n<\/li>\n<li><code>rows.Next()<\/code>\u4f1a\u6307\u660e\u662f\u5426\u8fd8\u6709\u672a\u8bfb\u53d6\u7684\u6570\u636e\u8bb0\u5f55\uff0c\u901a\u5e38\u7528\u4e8e\u8fed\u4ee3\u7ed3\u679c\u96c6\u3002\u8fed\u4ee3\u4e2d\u7684\u9519\u8bef\u4f1a\u5bfc\u81f4<code>rows.Next()<\/code>\u8fd4\u56de<code>false<\/code>\u3002<\/li>\n<li><code>rows.Scan()<\/code>\u7528\u4e8e\u5728\u8fed\u4ee3\u4e2d\u83b7\u53d6\u4e00\u884c\u7ed3\u679c\u3002\u6570\u636e\u5e93\u4f1a\u4f7f\u7528wire protocal\u901a\u8fc7TCP\/UnixSocket\u4f20\u8f93\u6570\u636e\uff0c\u5bf9Pg\u800c\u8a00\uff0c\u6bcf\u4e00\u884c\u5b9e\u9645\u4e0a\u5bf9\u5e94\u4e00\u6761<code>DataRow<\/code>\u6d88\u606f\u3002<code>Scan<\/code>\u63a5\u53d7\u53d8\u91cf\u5730\u5740\uff0c\u89e3\u6790<code>DataRow<\/code>\u6d88\u606f\u5e76\u586b\u5165\u76f8\u5e94\u53d8\u91cf\u4e2d\u3002\u56e0\u4e3aGo\u8bed\u8a00\u662f\u5f3a\u7c7b\u578b\u7684\uff0c\u6240\u4ee5\u7528\u6237\u9700\u8981\u521b\u5efa\u76f8\u5e94\u7c7b\u578b\u7684\u53d8\u91cf\u5e76\u5728<code>rows.Scan<\/code>\u4e2d\u4f20\u5165\u5176\u6307\u9488\uff0c<code>Scan<\/code>\u51fd\u6570\u4f1a\u6839\u636e\u76ee\u6807\u53d8\u91cf\u7684\u7c7b\u578b\u6267\u884c\u76f8\u5e94\u8f6c\u6362\u3002<\/li>\n<\/ol>\n<p>\u4f8b\u5982\u67d0\u67e5\u8be2\u8fd4\u56de\u4e00\u4e2a\u5355\u5217<code>string<\/code>\u7ed3\u679c\u96c6\uff0c\u7528\u6237\u53ef\u4ee5\u4f20\u5165<code>[]byte<\/code>\u6216<code>string<\/code>\u7c7b\u578b\u53d8\u91cf\u7684\u5730\u5740\uff0cGo\u4f1a\u5c06\u539f\u59cb\u4e8c\u8fdb\u5236\u6570\u636e\u6216\u5176\u5b57\u7b26\u4e32\u5f62\u5f0f\u586b\u5165\u5176\u4e2d\u3002\u4f46\u5982\u679c\u7528\u6237\u77e5\u9053\u8fd9\u4e00\u5217\u59cb\u7ec8\u5b58\u50a8\u7740\u6570\u5b57\u5b57\u9762\u503c\uff0c\u90a3\u4e48\u76f8\u6bd4\u4f20\u5165<code>string<\/code>\u5730\u5740\u540e\u624b\u52a8\u4f7f\u7528<code>strconv.ParseInt()<\/code>\u89e3\u6790\uff0c\u66f4\u63a8\u8350\u7684\u505a\u6cd5\u662f\u76f4\u63a5\u4f20\u5165\u4e00\u4e2a\u6574\u578b\u53d8\u91cf\u7684\u5730\u5740\uff08\u5982\u4e0a\u9762\u6240\u793a\uff09\uff0cGo\u4f1a\u66ff\u7528\u6237\u5b8c\u6210\u89e3\u6790\u5de5\u4f5c\u3002\u5982\u679c\u89e3\u6790\u51fa\u9519\uff0c<code>Scan<\/code>\u4f1a\u8fd4\u56de\u76f8\u5e94\u7684\u9519\u8bef\u3002<\/p>\n<ol>\n<li><code>rows.Err()<\/code>\u7528\u4e8e\u5728\u9000\u51fa\u8fed\u4ee3\u540e\u68c0\u67e5\u9519\u8bef\u3002\u6b63\u5e38\u60c5\u51b5\u4e0b\u8fed\u4ee3\u9000\u51fa\u662f\u56e0\u4e3a\u5185\u90e8\u4ea7\u751f\u7684EOF\u9519\u8bef\uff0c\u4f7f\u5f97\u4e0b\u4e00\u6b21<code>rows.Next() == false<\/code>\uff0c\u4ece\u800c\u7ec8\u6b62\u5faa\u73af\uff1b\u5728\u8fed\u4ee3\u7ed3\u675f\u540e\u8981\u68c0\u67e5\u9519\u8bef\uff0c\u4ee5\u786e\u4fdd\u8fed\u4ee3\u662f\u56e0\u4e3a\u6570\u636e\u8bfb\u53d6\u5b8c\u6bd5\uff0c\u800c\u975e\u5176\u4ed6\u201c\u771f\u6b63\u201d\u9519\u8bef\u800c\u7ed3\u675f\u7684\u3002\u904d\u5386\u7ed3\u679c\u96c6\u7684\u8fc7\u7a0b\u5b9e\u9645\u4e0a\u662f\u7f51\u7edcIO\u7684\u8fc7\u7a0b\uff0c\u53ef\u80fd\u51fa\u73b0\u5404\u79cd\u9519\u8bef\u3002\u5065\u58ee\u7684\u7a0b\u5e8f\u5e94\u5f53\u8003\u8651\u8fd9\u4e9b\u53ef\u80fd\uff0c\u800c\u4e0d\u80fd\u603b\u662f\u5047\u8bbe\u4e00\u5207\u6b63\u5e38\u3002<\/li>\n<li><code>rows.Close()<\/code>\u7528\u4e8e\u5173\u95ed\u7ed3\u679c\u96c6\u3002\u7ed3\u679c\u96c6\u5f15\u7528\u4e86\u6570\u636e\u5e93\u8fde\u63a5\uff0c\u5e76\u4f1a\u4ece\u4e2d\u8bfb\u53d6\u7ed3\u679c\u3002\u8bfb\u53d6\u5b8c\u4e4b\u540e\u5fc5\u987b\u5173\u95ed\u5b83\u624d\u80fd\u907f\u514d\u8d44\u6e90\u6cc4\u9732\u3002\u53ea\u8981\u7ed3\u679c\u96c6\u4ecd\u7136\u6253\u5f00\u7740\uff0c\u76f8\u5e94\u7684\u5e95\u5c42\u8fde\u63a5\u5c31\u5904\u4e8e\u5fd9\u788c\u72b6\u6001\uff0c\u4e0d\u80fd\u88ab\u5176\u4ed6\u67e5\u8be2\u4f7f\u7528\u3002<\/li>\n<\/ol>\n<p>\u56e0\u9519\u8bef(\u5305\u62ecEOF)\u5bfc\u81f4\u7684\u8fed\u4ee3\u9000\u51fa\u4f1a\u81ea\u52a8\u8c03\u7528<code>rows.Close()<\/code>\u5173\u95ed\u7ed3\u679c\u96c6\uff08\u548c\u91ca\u653e\u5e95\u5c42\u8fde\u63a5\uff09\u3002\u4f46\u5982\u679c\u7a0b\u5e8f\u81ea\u884c\u610f\u5916\u5730\u9000\u51fa\u4e86\u5faa\u73af\uff0c\u4f8b\u5982\u4e2d\u9014<code>break &amp; return<\/code>\uff0c\u7ed3\u679c\u96c6\u5c31\u4e0d\u4f1a\u88ab\u5173\u95ed\uff0c\u4ea7\u751f\u8d44\u6e90\u6cc4\u9732\u3002<code>rows.Close<\/code>\u65b9\u6cd5\u662f\u5e42\u7b49\u7684\uff0c\u91cd\u590d\u8c03\u7528\u4e0d\u4f1a\u4ea7\u751f\u526f\u4f5c\u7528\uff0c\u56e0\u6b64\u5efa\u8bae\u4f7f\u7528\u00a0<code>defer rows.Close()<\/code>\u6765\u5173\u95ed\u7ed3\u679c\u96c6\u3002<\/p>\n<p>\u4ee5\u4e0a\u5c31\u662f\u5728Go\u4e2d\u4f7f\u7528\u6570\u636e\u5e93\u7684\u6807\u51c6\u65b9\u5f0f\u3002<\/p>\n<h3 id=\"6\">4.2 \u5355\u884c\u67e5\u8be2<\/h3>\n<p>\u5982\u679c\u4e00\u4e2a\u67e5\u8be2\u6bcf\u6b21\u6700\u591a\u8fd4\u56de\u4e00\u884c\uff0c\u90a3\u4e48\u53ef\u4ee5\u7528\u5feb\u6377\u7684\u5355\u884c\u67e5\u8be2\u6765\u66ff\u4ee3\u5197\u957f\u7684\u6807\u51c6\u67e5\u8be2\uff0c\u4f8b\u5982\u4e0a\u4f8b\u53ef\u6539\u5199\u4e3a\uff1a<\/p>\n<pre><code class=\"hljs cs\"><span class=\"hljs-keyword\">var<\/span> sum <span class=\"hljs-keyword\">int<\/span>\r\nerr := db.QueryRow(<span class=\"hljs-string\">\"SELECT sum(n) FROM (SELECT generate_series(1,$1) as n) a;\"<\/span>, <span class=\"hljs-number\">10<\/span>).Scan(&amp;sum)\r\n<span class=\"hljs-keyword\">if<\/span> err != nil {\r\n    fmt.Println(err)\r\n}\r\nfmt.Println(sum)<\/code><\/pre>\n<p>\u4e0d\u540c\u4e8e<code>Query<\/code>\uff0c\u5982\u679c\u67e5\u8be2\u53d1\u751f\u9519\u8bef\uff0c\u9519\u8bef\u4f1a\u5ef6\u8fdf\u5230\u8c03\u7528<code>Scan()<\/code>\u65f6\u7edf\u4e00\u8fd4\u56de\uff0c\u51cf\u5c11\u4e86\u4e00\u6b21\u9519\u8bef\u5904\u7406\u5224\u65ad\u3002\u540c\u65f6<code>QueryRow<\/code>\u4e5f\u907f\u514d\u4e86\u624b\u52a8\u64cd\u4f5c\u7ed3\u679c\u96c6\u7684\u9ebb\u70e6\u3002<\/p>\n<p>\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u5bf9\u4e8e\u5355\u884c\u67e5\u8be2\uff0cGo\u5c06\u6ca1\u6709\u7ed3\u679c\u7684\u60c5\u51b5\u89c6\u4e3a\u9519\u8bef\u3002<code>sql<\/code>\u5305\u4e2d\u5b9a\u4e49\u4e86\u4e00\u4e2a\u7279\u6b8a\u7684\u9519\u8bef\u5e38\u91cf<code>ErrNoRows<\/code>\uff0c\u5f53\u7ed3\u679c\u4e3a\u7a7a\u65f6\uff0c<code>QueryRow().Scan()<\/code>\u4f1a\u8fd4\u56de\u5b83\u3002<\/p>\n<h3 id=\"7\">4.3 \u4fee\u6539\u6570\u636e<\/h3>\n<p>\u4ec0\u4e48\u65f6\u5019\u7528<code>Exec<\/code>\uff0c\u4ec0\u4e48\u65f6\u5019\u7528<code>Query<\/code>\uff0c\u8fd9\u662f\u4e00\u4e2a\u95ee\u9898\u3002\u901a\u5e38<code>DDL<\/code>\u548c\u589e\u5220\u6539\u4f7f\u7528<code>Exec<\/code>\uff0c\u8fd4\u56de\u7ed3\u679c\u96c6\u7684\u67e5\u8be2\u4f7f\u7528<code>Query<\/code>\u3002\u4f46\u8fd9\u4e0d\u662f\u7edd\u5bf9\u7684\uff0c\u8fd9\u5b8c\u5168\u53d6\u51b3\u4e8e\u7528\u6237\u662f\u5426\u5e0c\u671b\u60f3\u8981\u83b7\u53d6\u8fd4\u56de\u7ed3\u679c\u3002\u4f8b\u5982\u5728PostgreSQL\u4e2d\uff1a<code>INSERT ... RETURNING *;<\/code>\u867d\u7136\u662f\u4e00\u6761\u63d2\u5165\u8bed\u53e5\uff0c\u4f46\u5b83\u4e5f\u6709\u8fd4\u56de\u7ed3\u679c\u96c6\uff0c\u6545\u5e94\u5f53\u4f7f\u7528<code>Query<\/code>\u800c\u4e0d\u662f<code>Exec<\/code>\u3002<\/p>\n<p><code>Query<\/code>\u548c<code>Exec<\/code>\u8fd4\u56de\u7684\u7ed3\u679c\u4e0d\u540c\uff0c\u4e24\u8005\u7684\u7b7e\u540d\u5206\u522b\u662f\uff1a<\/p>\n<pre><code class=\"go hljs css\"><span class=\"hljs-selector-tag\">func<\/span> (<span class=\"hljs-selector-tag\">s<\/span> *<span class=\"hljs-selector-tag\">Stmt<\/span>) <span class=\"hljs-selector-tag\">Query<\/span>(<span class=\"hljs-selector-tag\">args<\/span> ..<span class=\"hljs-selector-class\">.interface<\/span>{}) (*<span class=\"hljs-selector-tag\">Rows<\/span>, <span class=\"hljs-selector-tag\">error<\/span>)\r\n<span class=\"hljs-selector-tag\">func<\/span> (<span class=\"hljs-selector-tag\">s<\/span> *<span class=\"hljs-selector-tag\">Stmt<\/span>) <span class=\"hljs-selector-tag\">Exec<\/span>(<span class=\"hljs-selector-tag\">args<\/span> ..<span class=\"hljs-selector-class\">.interface<\/span>{}) (<span class=\"hljs-selector-tag\">Result<\/span>, <span class=\"hljs-selector-tag\">error<\/span>) <\/code><\/pre>\n<p><code>Exec<\/code>\u4e0d\u9700\u8981\u8fd4\u56de\u6570\u636e\u96c6\uff0c\u8fd4\u56de\u7684\u7ed3\u679c\u662f<code>Result<\/code>\uff0c<code>Result<\/code>\u63a5\u53e3\u5141\u8bb8\u83b7\u53d6\u6267\u884c\u7ed3\u679c\u7684\u5143\u6570\u636e<\/p>\n<pre><code class=\"go hljs cs\">type Result <span class=\"hljs-keyword\">interface<\/span> {\r\n    <span class=\"hljs-comment\">\/\/ \u7528\u4e8e\u8fd4\u56de\u81ea\u589eID\uff0c\u5e76\u4e0d\u662f\u6240\u6709\u7684\u5173\u7cfb\u578b\u6570\u636e\u5e93\u90fd\u6709\u8fd9\u4e2a\u529f\u80fd\u3002<\/span>\r\n    LastInsertId() (int64, error)\r\n    <span class=\"hljs-comment\">\/\/ \u8fd4\u56de\u53d7\u5f71\u54cd\u7684\u884c\u6570\u3002<\/span>\r\n    RowsAffected() (int64, error)\r\n}<\/code><\/pre>\n<p><code>Exec<\/code>\u7684\u7528\u6cd5\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n<pre><code class=\"go hljs sql\">db.Exec(`<span class=\"hljs-keyword\">CREATE<\/span> <span class=\"hljs-keyword\">TABLE<\/span> test_users(<span class=\"hljs-keyword\">id<\/span> <span class=\"hljs-built_in\">INTEGER<\/span> PRIMARY <span class=\"hljs-keyword\">KEY<\/span> ,<span class=\"hljs-keyword\">name<\/span> <span class=\"hljs-built_in\">TEXT<\/span>);`)\r\ndb.Exec(`<span class=\"hljs-keyword\">TRUNCATE<\/span> test_users;`)\r\nstmt, err := db.Prepare(`<span class=\"hljs-keyword\">INSERT<\/span> <span class=\"hljs-keyword\">INTO<\/span> test_users(<span class=\"hljs-keyword\">id<\/span>,<span class=\"hljs-keyword\">name<\/span>) <span class=\"hljs-keyword\">VALUES<\/span> ($<span class=\"hljs-number\">1<\/span>,$<span class=\"hljs-number\">2<\/span>) <span class=\"hljs-keyword\">RETURNING<\/span> <span class=\"hljs-keyword\">id<\/span><span class=\"hljs-string\">`)\r\nif err != nil {\r\n    fmt.Println(err.Error())\r\n}\r\nres, err := stmt.Exec(1, \"Alice\")\r\n\r\nif err != nil {\r\n    fmt.Println(err)\r\n} else {\r\n    fmt.Println(res.RowsAffected())\r\n    fmt.Println(res.LastInsertId())\r\n}<\/span><\/code><\/pre>\n<p>\u76f8\u6bd4\u4e4b\u4e0b<code>Query<\/code>\u5219\u4f1a\u8fd4\u56de\u7ed3\u679c\u96c6\u5bf9\u8c61<code>*Rows<\/code>\uff0c\u4f7f\u7528\u65b9\u5f0f\u89c1\u4e0a\u8282\u3002\u5176\u7279\u4f8b<code>QueryRow<\/code>\u4f7f\u7528\u65b9\u5f0f\u5982\u4e0b\uff1a<\/p>\n<pre><code class=\"go hljs sql\">db.Exec(`<span class=\"hljs-keyword\">CREATE<\/span> <span class=\"hljs-keyword\">TABLE<\/span> test_users(<span class=\"hljs-keyword\">id<\/span> <span class=\"hljs-built_in\">INTEGER<\/span> PRIMARY <span class=\"hljs-keyword\">KEY<\/span> ,<span class=\"hljs-keyword\">name<\/span> <span class=\"hljs-built_in\">TEXT<\/span>);`)\r\ndb.Exec(`<span class=\"hljs-keyword\">TRUNCATE<\/span> test_users;`)\r\nstmt, err := db.Prepare(`<span class=\"hljs-keyword\">INSERT<\/span> <span class=\"hljs-keyword\">INTO<\/span> test_users(<span class=\"hljs-keyword\">id<\/span>,<span class=\"hljs-keyword\">name<\/span>) <span class=\"hljs-keyword\">VALUES<\/span> ($<span class=\"hljs-number\">1<\/span>,$<span class=\"hljs-number\">2<\/span>) <span class=\"hljs-keyword\">RETURNING<\/span> <span class=\"hljs-keyword\">id<\/span><span class=\"hljs-string\">`)\r\nif err != nil {\r\n    fmt.Println(err.Error())\r\n}\r\nvar returnID int\r\nerr = stmt.QueryRow(4, \"Alice\").Scan(&amp;returnID)\r\nif err != nil {\r\n    fmt.Println(err)\r\n} else {\r\n    fmt.Println(returnID)\r\n}<\/span><\/code><\/pre>\n<p>\u540c\u6837\u7684\u8bed\u53e5\u4f7f\u7528<code>Exec<\/code>\u548c<code>Query<\/code>\u6267\u884c\u6709\u5de8\u5927\u7684\u5dee\u522b\u3002\u5982\u4e0a\u6587\u6240\u8ff0\uff0c<code>Query<\/code>\u4f1a\u8fd4\u56de\u7ed3\u679c\u96c6<code>Rows<\/code>\uff0c\u800c\u5b58\u5728\u672a\u8bfb\u53d6\u6570\u636e\u7684<code>Rows<\/code>\u5176\u5b9e\u4f1a\u5360\u7528\u5e95\u5c42\u8fde\u63a5\u76f4\u5230<code>rows.Close()<\/code>\u4e3a\u6b62\u3002\u56e0\u6b64\uff0c\u4f7f\u7528<code>Query<\/code>\u4f46\u4e0d\u8bfb\u53d6\u8fd4\u56de\u7ed3\u679c\uff0c\u4f1a\u5bfc\u81f4\u5e95\u5c42\u8fde\u63a5\u6c38\u8fdc\u65e0\u6cd5\u91ca\u653e\u3002<code>database\/sql<\/code>\u671f\u671b\u7528\u6237\u80fd\u591f\u7528\u5b8c\u5c31\u628a\u8fde\u63a5\u8fd8\u56de\u6765\uff0c\u6240\u4ee5\u8fd9\u6837\u7684\u7528\u6cd5\u5f88\u5feb\u5c31\u4f1a\u5bfc\u81f4\u8d44\u6e90\u8017\u5c3d\uff08\u8fde\u63a5\u8fc7\u591a\uff09\u3002\u6240\u4ee5\uff0c\u5e94\u8be5\u7528<code>Exec<\/code>\u7684\u8bed\u53e5\u7edd\u4e0d\u53ef\u7528<code>Query<\/code>\u6765\u6267\u884c\u3002<\/p>\n<h3 id=\"8\">4.4 \u51c6\u5907\u67e5\u8be2<\/h3>\n<p>\u5728\u4e0a\u4e00\u8282\u7684\u4e24\u4e2a\u4f8b\u5b50\u4e2d\uff0c\u6ca1\u6709\u76f4\u63a5\u4f7f\u7528\u6570\u636e\u5e93\u7684<code>Query<\/code>\u548c<code>Exec<\/code>\u65b9\u6cd5\uff0c\u800c\u662f\u9996\u5148\u6267\u884c\u4e86<code>db.Prepare<\/code>\u83b7\u53d6\u51c6\u5907\u597d\u7684\u8bed\u53e5(prepared statement)\u3002\u51c6\u5907\u597d\u7684\u8bed\u53e5<code>Stmt<\/code>\u548c<code>sql.DB<\/code>\u4e00\u6837\uff0c\u90fd\u53ef\u4ee5\u6267\u884c<code>Query<\/code>\u3001<code>Exec<\/code>\u7b49\u65b9\u6cd5\u3002<\/p>\n<h4 id=\"9\">\u51c6\u5907\u8bed\u53e5\u7684\u4f18\u52bf<\/h4>\n<p>\u5728\u67e5\u8be2\u524d\u8fdb\u884c\u51c6\u5907\u662fGo\u8bed\u8a00\u4e2d\u7684\u60ef\u7528\u6cd5\uff0c\u591a\u6b21\u4f7f\u7528\u7684\u67e5\u8be2\u8bed\u53e5\u5e94\u5f53\u8fdb\u884c\u51c6\u5907\uff08<code>Prepare<\/code>\uff09\u3002\u51c6\u5907\u67e5\u8be2\u7684\u7ed3\u679c\u662f\u4e00\u4e2a\u51c6\u5907\u597d\u7684\u8bed\u53e5\uff08prepared statement\uff09\uff0c\u8bed\u53e5\u4e2d\u53ef\u4ee5\u5305\u542b\u6267\u884c\u65f6\u6240\u9700\u53c2\u6570\u7684\u5360\u4f4d\u7b26\uff08\u5373\u7ed1\u5b9a\u503c\uff09\u3002\u51c6\u5907\u67e5\u8be2\u6bd4\u62fc\u5b57\u7b26\u4e32\u7684\u65b9\u5f0f\u597d\u5f88\u591a\uff0c\u5b83\u53ef\u4ee5\u8f6c\u4e49\u53c2\u6570\uff0c\u907f\u514dSQL\u6ce8\u5165\u3002\u540c\u65f6\uff0c\u51c6\u5907\u67e5\u8be2\u5bf9\u4e8e\u4e00\u4e9b\u6570\u636e\u5e93\u4e5f\u7701\u53bb\u4e86\u89e3\u6790\u548c\u751f\u6210\u6267\u884c\u8ba1\u5212\u7684\u5f00\u9500\uff0c\u6709\u5229\u4e8e\u6027\u80fd\u3002<\/p>\n<h4 id=\"10\">\u5360\u4f4d\u7b26<\/h4>\n<p>PostgreSQL\u4f7f\u7528<code>$N<\/code>\u4f5c\u4e3a\u5360\u4f4d\u7b26\uff0c<code>N<\/code>\u662f\u4e00\u4e2a\u4ece1\u5f00\u59cb\u9012\u589e\u7684\u6574\u6570\uff0c\u4ee3\u8868\u53c2\u6570\u7684\u4f4d\u7f6e\uff0c\u65b9\u4fbf\u53c2\u6570\u7684\u91cd\u590d\u4f7f\u7528\u3002MySQL\u4f7f\u7528<code>?<\/code>\u4f5c\u4e3a\u5360\u4f4d\u7b26\uff0cSQLite\u4e24\u79cd\u5360\u4f4d\u7b26\u90fd\u53ef\u4ee5\uff0c\u800cOracle\u5219\u4f7f\u7528<code>:param1<\/code>\u7684\u5f62\u5f0f\u3002<\/p>\n<pre><code class=\"hljs ruby\">MySQL               PostgreSQL            Oracle\r\n=====               ==========            ======\r\nWHERE col = ?       WHERE col = $1        WHERE col = <span class=\"hljs-symbol\">:col<\/span>\r\nVALUES(?, ?, ?)     VALUES($1, $2, $3)    VALUES(<span class=\"hljs-symbol\">:val1<\/span>, <span class=\"hljs-symbol\">:val2<\/span>, <span class=\"hljs-symbol\">:val3<\/span>)<\/code><\/pre>\n<p>\u4ee5<code>PostgreSQL<\/code>\u4e3a\u4f8b\uff0c\u5728\u4e0a\u9762\u7684\u4f8b\u5b50\u4e2d\uff1a<code>\"SELECT generate_series(1,$1)\"<\/code>\u00a0\u5c31\u7528\u5230\u4e86<code>$N<\/code>\u7684\u5360\u4f4d\u7b26\u5f62\u5f0f\uff0c\u5e76\u5728\u540e\u9762\u63d0\u4f9b\u4e86\u4e0e\u5360\u4f4d\u7b26\u6570\u76ee\u5339\u914d\u7684\u53c2\u6570\u4e2a\u6570\u3002<\/p>\n<h4 id=\"11\">\u5e95\u5c42\u5185\u5e55<\/h4>\n<p>\u51c6\u5907\u8bed\u53e5\u6709\u7740\u5404\u79cd\u4f18\u70b9\uff1a\u5b89\u5168\uff0c\u9ad8\u6548\uff0c\u65b9\u4fbf\u3002\u4f46Go\u4e2d\u5b9e\u73b0\u5b83\u7684\u65b9\u5f0f\u53ef\u80fd\u548c\u7528\u6237\u6240\u8bbe\u60f3\u7684\u6709\u8f7b\u5fae\u4e0d\u540c\uff0c\u5c24\u5176\u662f\u5173\u4e8e\u548c<code>database\/sql<\/code>\u5185\u90e8\u5176\u4ed6\u5bf9\u8c61\u4ea4\u4e92\u7684\u90e8\u5206\u3002<\/p>\n<p>\u5728\u6570\u636e\u5e93\u5c42\u9762\uff0c\u51c6\u5907\u8bed\u53e5<code>Stmt<\/code>\u662f\u4e0e\u5355\u4e2a\u6570\u636e\u5e93\u8fde\u63a5\u7ed1\u5b9a\u7684\u3002\u901a\u5e38\u7684\u6d41\u7a0b\u662f\uff1a\u5ba2\u6237\u7aef\u5411\u670d\u52a1\u5668\u53d1\u9001\u5e26\u6709\u5360\u4f4d\u7b26\u7684\u67e5\u8be2\u8bed\u53e5\u7528\u4e8e\u51c6\u5907\uff0c\u670d\u52a1\u5668\u8fd4\u56de\u4e00\u4e2a\u8bed\u53e5ID\uff0c\u5ba2\u6237\u7aef\u5728\u5b9e\u9645\u6267\u884c\u65f6\uff0c\u53ea\u9700\u8981\u4f20\u8f93\u8bed\u53e5ID\u548c\u76f8\u5e94\u7684\u53c2\u6570\u5373\u53ef\u3002\u56e0\u6b64\u51c6\u5907\u8bed\u53e5\u65e0\u6cd5\u5728\u8fde\u63a5\u4e4b\u95f4\u5171\u4eab\uff0c\u5f53\u4f7f\u7528\u65b0\u7684\u6570\u636e\u5e93\u8fde\u63a5\u65f6\uff0c\u5fc5\u987b\u91cd\u65b0\u51c6\u5907\u3002<\/p>\n<p><code>database\/sql<\/code>\u5e76\u6ca1\u6709\u76f4\u63a5\u66b4\u9732\u51fa\u6570\u636e\u5e93\u8fde\u63a5\u3002\u7528\u6237\u662f\u5728<code>DB<\/code>\u6216<code>Tx<\/code>\u4e0a\u6267\u884c<code>Prepare<\/code>\uff0c\u800c\u4e0d\u662f<code>Conn<\/code>\u3002\u56e0\u6b64<code>database\/sql<\/code>\u63d0\u4f9b\u4e86\u4e00\u4e9b\u4fbf\u5229\u5904\u7406\uff0c\u4f8b\u5982\u81ea\u52a8\u91cd\u8bd5\u3002\u8fd9\u4e9b\u673a\u5236\u9690\u85cf\u5728Driver\u4e2d\u5b9e\u73b0\uff0c\u800c\u4e0d\u4f1a\u66b4\u9732\u5728\u7528\u6237\u4ee3\u7801\u4e2d\u3002\u5176\u5de5\u4f5c\u539f\u7406\u662f\uff1a\u5f53\u7528\u6237\u51c6\u5907\u4e00\u6761\u8bed\u53e5\u65f6\uff0c\u5b83\u5728\u8fde\u63a5\u6c60\u4e2d\u7684\u4e00\u4e2a\u8fde\u63a5\u4e0a\u8fdb\u884c\u51c6\u5907\u3002<code>Stmt<\/code>\u5bf9\u8c61\u4f1a\u5f15\u7528\u5b83\u5b9e\u9645\u4f7f\u7528\u7684\u8fde\u63a5\u3002\u5f53\u6267\u884c<code>Stmt<\/code>\u65f6\uff0c\u5b83\u4f1a\u5c1d\u8bd5\u4f1a\u7528\u5f15\u7528\u7684\u8fde\u63a5\u3002\u5982\u679c\u90a3\u4e2a\u8fde\u63a5\u5fd9\u788c\u6216\u5df2\u7ecf\u88ab\u5173\u95ed\uff0c\u5b83\u4f1a\u83b7\u53d6\u4e00\u4e2a\u65b0\u7684\u8fde\u63a5\uff0c\u5e76\u5728\u8fde\u63a5\u4e0a\u91cd\u65b0\u51c6\u5907\uff0c\u7136\u540e\u518d\u6267\u884c\u3002<\/p>\n<p>\u56e0\u4e3a\u5f53\u539f\u6709\u8fde\u63a5\u5fd9\u65f6\uff0c<code>Stmt<\/code>\u4f1a\u5728\u5176\u4ed6\u8fde\u63a5\u4e0a\u91cd\u65b0\u51c6\u5907\u3002\u56e0\u6b64\u5f53\u9ad8\u5e76\u53d1\u5730\u8bbf\u95ee\u6570\u636e\u5e93\u65f6\uff0c\u5927\u91cf\u7684\u8fde\u63a5\u5904\u4e8e\u5fd9\u788c\u72b6\u6001\uff0c\u8fd9\u4f1a\u5bfc\u81f4<code>Stmt<\/code>\u4e0d\u65ad\u83b7\u53d6\u65b0\u7684\u8fde\u63a5\u5e76\u6267\u884c\u51c6\u5907\uff0c\u6700\u7ec8\u5bfc\u81f4\u8d44\u6e90\u6cc4\u9732\uff0c\u751a\u81f3\u8d85\u51fa\u670d\u52a1\u7aef\u5141\u8bb8\u7684\u8bed\u53e5\u6570\u76ee\u4e0a\u9650\u3002\u6240\u4ee5\u901a\u5e38\u5e94\u5c3d\u91cf\u91c7\u7528\u6247\u5165\u7684\u65b9\u5f0f\u51cf\u5c0f\u6570\u636e\u5e93\u8bbf\u95ee\u5e76\u53d1\u6570\u3002<\/p>\n<h4 id=\"12\">\u67e5\u8be2\u7684\u5fae\u5999\u4e4b\u5904<\/h4>\n<p>\u6570\u636e\u5e93\u8fde\u63a5\u5176\u5b9e\u662f\u5b9e\u73b0\u4e86<code>Begin,Close,Prepare<\/code>\u65b9\u6cd5\u7684\u63a5\u53e3\u3002<\/p>\n<pre><code class=\"go hljs cs\">type Conn <span class=\"hljs-keyword\">interface<\/span> {\r\n        Prepare(query <span class=\"hljs-keyword\">string<\/span>) (Stmt, error)\r\n        Close() <span class=\"hljs-function\">error\r\n        <span class=\"hljs-title\">Begin<\/span>() (<span class=\"hljs-params\">Tx, error<\/span>)\r\n}<\/span><\/code><\/pre>\n<p>\u6240\u4ee5\u8fde\u63a5\u63a5\u53e3\u4e0a\u5b9e\u9645\u5e76\u6ca1\u6709<code>Exec<\/code>\uff0c<code>Query<\/code>\u65b9\u6cd5\uff0c\u8fd9\u4e9b\u65b9\u6cd5\u5176\u5b9e\u5b9a\u4e49\u5728<code>Prepare<\/code>\u8fd4\u56de\u7684<code>Stmt<\/code>\u4e0a\u3002\u5bf9\u4e8eGo\u800c\u8a00\uff0c\u8fd9\u610f\u5473\u7740<code>db.Query()<\/code>\u5b9e\u9645\u4e0a\u6267\u884c\u4e86\u4e09\u4e2a\u64cd\u4f5c\uff1a\u9996\u5148\u5bf9\u67e5\u8be2\u8bed\u53e5\u505a\u4e86\u51c6\u5907\uff0c\u7136\u540e\u6267\u884c\u67e5\u8be2\u8bed\u53e5\uff0c\u6700\u540e\u5173\u95ed\u51c6\u5907\u597d\u7684\u8bed\u53e5\u3002\u8fd9\u5bf9\u6570\u636e\u5e93\u800c\u8a00\uff0c\u5176\u5b9e\u662f3\u4e2a\u6765\u56de\u3002\u8bbe\u8ba1\u7c97\u7cd9\u7684\u7a0b\u5e8f\u4e0e\u7b80\u964b\u5b9e\u73b0\u9a71\u52a8\u53ef\u80fd\u4f1a\u8ba9\u5e94\u7528\u4e0e\u6570\u636e\u5e93\u4ea4\u4e92\u7684\u6b21\u6570\u589e\u81f33\u500d\u3002\u597d\u5728\u7edd\u5927\u591a\u6570\u6570\u636e\u5e93\u9a71\u52a8\u5bf9\u4e8e\u8fd9\u79cd\u60c5\u51b5\u6709\u4f18\u5316\uff0c\u5982\u679c\u9a71\u52a8\u5b9e\u73b0<code>sql.Queryer<\/code>\u63a5\u53e3\uff1a<\/p>\n<pre><code class=\"go hljs cs\">type Queryer <span class=\"hljs-keyword\">interface<\/span> {\r\n        Query(query <span class=\"hljs-keyword\">string<\/span>, args []Value) (Rows, error)\r\n}<\/code><\/pre>\n<p>\u90a3\u4e48<code>database\/sql<\/code>\u5c31\u4e0d\u4f1a\u518d\u8fdb\u884c<code>Prepare-Execute-Close<\/code>\u7684\u67e5\u8be2\u6a21\u5f0f\uff0c\u800c\u662f\u76f4\u63a5\u4f7f\u7528\u9a71\u52a8\u5b9e\u73b0\u7684<code>Query<\/code>\u65b9\u6cd5\u5411\u6570\u636e\u5e93\u53d1\u9001\u67e5\u8be2\u3002\u5bf9\u4e8e\u67e5\u8be2\u90fd\u662f\u5373\u62fc\u5373\u7528\uff0c\u4e5f\u4e0d\u62c5\u5fc3\u5b89\u5168\u95ee\u9898\u7684\u60c5\u51b5\u4e0b\uff0c\u76f4\u63a5<code>Query<\/code>\u53ef\u4ee5\u6709\u6548\u51cf\u5c11\u6027\u80fd\u5f00\u9500\u3002<\/p>\n<h2 id=\"13\">5. \u4f7f\u7528\u4e8b\u52a1<\/h2>\n<p>\u4e8b\u7269\u662f\u5173\u7cfb\u578b\u6570\u636e\u5e93\u7684\u6838\u5fc3\u7279\u6027\u3002Go\u4e2d\u4e8b\u52a1\uff08Tx\uff09\u662f\u4e00\u4e2a\u6301\u6709\u6570\u636e\u5e93\u8fde\u63a5\u7684\u5bf9\u8c61\uff0c\u5b83\u5141\u8bb8\u7528\u6237\u5728<strong>\u540c\u4e00\u4e2a\u8fde\u63a5<\/strong>\u4e0a\u6267\u884c\u4e0a\u9762\u63d0\u5230\u7684\u5404\u7c7b\u64cd\u4f5c\u3002<\/p>\n<h4 id=\"14\">\u4e8b\u52a1\u57fa\u672c\u64cd\u4f5c<\/h4>\n<p>\u901a\u8fc7<code>db.Begin()<\/code>\u6765\u5f00\u542f\u4e00\u4e2a\u4e8b\u52a1\uff0c<code>Begin<\/code>\u65b9\u6cd5\u4f1a\u8fd4\u56de\u4e00\u4e2a\u4e8b\u52a1\u5bf9\u8c61<code>Tx<\/code>\u3002\u5728\u7ed3\u679c\u53d8\u91cf<code>Tx<\/code>\u4e0a\u8c03\u7528<code>Commit()<\/code>\u6216\u8005<code>Rollback()<\/code>\u65b9\u6cd5\u4f1a\u63d0\u4ea4\u6216\u56de\u6eda\u53d8\u66f4\uff0c\u5e76\u5173\u95ed\u4e8b\u52a1\u3002\u5728\u5e95\u5c42\uff0c<code>Tx<\/code>\u4f1a\u4ece\u8fde\u63a5\u6c60\u4e2d\u83b7\u5f97\u4e00\u4e2a\u8fde\u63a5\u5e76\u5728\u4e8b\u52a1\u8fc7\u7a0b\u4e2d\u4fdd\u6301\u5bf9\u5b83\u7684\u72ec\u5360\u3002\u4e8b\u52a1\u5bf9\u8c61<code>Tx<\/code>\u4e0a\u7684\u65b9\u6cd5\u4e0e\u6570\u636e\u5e93\u5bf9\u8c61<code>sql.DB<\/code>\u7684\u65b9\u6cd5\u4e00\u4e00\u5bf9\u5e94\uff0c\u4f8b\u5982<code>Query,Exec<\/code>\u7b49\u3002\u4e8b\u52a1\u5bf9\u8c61\u4e5f\u53ef\u4ee5\u51c6\u5907(prepare)\u67e5\u8be2\uff0c\u7531\u4e8b\u52a1\u521b\u5efa\u7684\u51c6\u5907\u8bed\u53e5\u4f1a\u663e\u5f0f\u7ed1\u5b9a\u5230\u521b\u5efa\u5b83\u7684\u4e8b\u52a1\u3002<\/p>\n<h4 id=\"15\">\u4e8b\u52a1\u6ce8\u610f\u4e8b\u9879<\/h4>\n<p>\u4f7f\u7528\u4e8b\u52a1\u5bf9\u8c61\u65f6\uff0c\u4e0d\u5e94\u518d\u6267\u884c\u4e8b\u52a1\u76f8\u5173\u7684SQL\u8bed\u53e5\uff0c\u4f8b\u5982<code>BEGIN,COMMIT<\/code>\u7b49\u3002\u8fd9\u53ef\u80fd\u4ea7\u751f\u4e00\u4e9b\u526f\u4f5c\u7528\uff1a<\/p>\n<ul>\n<li><code>Tx<\/code>\u5bf9\u8c61\u4e00\u76f4\u4fdd\u6301\u6253\u5f00\u72b6\u6001\uff0c\u4ece\u800c\u5360\u7528\u4e86\u8fde\u63a5\u3002<\/li>\n<li>\u6570\u636e\u5e93\u72b6\u6001\u4e0d\u518d\u4e0eGo\u4e2d\u76f8\u5173\u53d8\u91cf\u7684\u72b6\u6001\u4fdd\u6301\u540c\u6b65\u3002<\/li>\n<li>\u4e8b\u52a1\u63d0\u524d\u7ec8\u6b62\u4f1a\u5bfc\u81f4\u4e00\u4e9b\u672c\u5e94\u5c5e\u4e8e\u4e8b\u52a1\u5185\u7684\u67e5\u8be2\u8bed\u53e5\u4e0d\u518d\u5c5e\u4e8e\u4e8b\u52a1\u7684\u4e00\u90e8\u5206\uff0c\u8fd9\u4e9b\u88ab\u6392\u9664\u7684\u8bed\u53e5\u6709\u53ef\u80fd\u4f1a\u7531\u522b\u7684\u6570\u636e\u5e93\u8fde\u63a5\u800c\u975e\u539f\u6709\u7684\u4e8b\u52a1\u4e13\u5c5e\u8fde\u63a5\u6267\u884c\u3002<\/li>\n<\/ul>\n<p>\u5f53\u5904\u4e8e\u4e8b\u52a1\u5185\u90e8\u65f6\uff0c\u5e94\u5f53\u4f7f\u7528<code>Tx<\/code>\u5bf9\u8c61\u7684\u65b9\u6cd5\u800c\u975e<code>DB<\/code>\u7684\u65b9\u6cd5\uff0c<code>DB<\/code>\u5bf9\u8c61\u5e76\u4e0d\u662f\u4e8b\u52a1\u7684\u4e00\u90e8\u5206\uff0c\u76f4\u63a5\u8c03\u7528\u6570\u636e\u5e93\u5bf9\u8c61\u7684\u65b9\u6cd5\u65f6\uff0c\u6240\u6267\u884c\u7684\u67e5\u8be2\u5e76\u4e0d\u5c5e\u4e8e\u4e8b\u52a1\u7684\u4e00\u90e8\u5206\uff0c\u6709\u53ef\u80fd\u7531\u5176\u4ed6\u8fde\u63a5\u6267\u884c\u3002<\/p>\n<h4 id=\"16\">Tx\u7684\u5176\u4ed6\u5e94\u7528\u573a\u666f<\/h4>\n<p>\u5982\u679c\u9700\u8981\u4fee\u6539\u8fde\u63a5\u7684\u72b6\u6001\uff0c\u4e5f\u9700\u8981\u7528\u5230<code>Tx<\/code>\u5bf9\u8c61\uff0c\u5373\u4f7f\u7528\u6237\u5e76\u4e0d\u9700\u8981\u4e8b\u52a1\u3002\u4f8b\u5982\uff1a<\/p>\n<ul>\n<li>\u521b\u5efa\u4ec5\u8fde\u63a5\u53ef\u89c1\u7684\u4e34\u65f6\u8868<\/li>\n<li>\u8bbe\u7f6e\u53d8\u91cf\uff0c\u4f8b\u5982<code>SET @var := somevalue<\/code><\/li>\n<li>\u4fee\u6539\u8fde\u63a5\u9009\u9879\uff0c\u4f8b\u5982\u5b57\u7b26\u96c6\uff0c\u8d85\u65f6\u8bbe\u7f6e\u3002<\/li>\n<\/ul>\n<p>\u5728<code>Tx<\/code>\u4e0a\u6267\u884c\u7684\u65b9\u6cd5\u90fd\u4fdd\u8bc1\u540c\u4e00\u4e2a\u5e95\u5c42\u8fde\u63a5\u6267\u884c\uff0c\u8fd9\u4f7f\u5f97\u5bf9\u8fde\u63a5\u72b6\u6001\u7684\u4fee\u6539\u5bf9\u540e\u7eed\u64cd\u4f5c\u8d77\u6548\u3002\u8fd9\u662fGo\u4e2d\u5b9e\u73b0\u8fd9\u79cd\u529f\u80fd\u7684\u6807\u51c6\u65b9\u5f0f\u3002<\/p>\n<h4 id=\"17\">\u5728\u4e8b\u52a1\u4e2d\u51c6\u5907\u8bed\u53e5<\/h4>\n<p>\u8c03\u7528<code>Tx.Prepare<\/code>\u4f1a\u521b\u5efa\u4e00\u4e2a\u4e0e\u4e8b\u52a1\u7ed1\u5b9a\u7684\u51c6\u5907\u8bed\u53e5\u3002\u5728\u4e8b\u52a1\u4e2d\u4f7f\u7528\u51c6\u5907\u8bed\u53e5\uff0c\u6709\u4e00\u4e2a\u7279\u6b8a\u95ee\u9898\u9700\u8981\u5173\u6ce8\uff1a\u4e00\u5b9a\u8981\u5728\u4e8b\u52a1\u7ed3\u675f\u524d\u5173\u95ed\u51c6\u5907\u8bed\u53e5\u3002<\/p>\n<p>\u5728\u4e8b\u52a1\u4e2d\u4f7f\u7528<code>defer stmt.Close()<\/code>\u662f\u76f8\u5f53\u5371\u9669\u7684\u3002\u56e0\u4e3a\u5f53\u4e8b\u52a1\u7ed3\u675f\u540e\uff0c\u5b83\u4f1a\u91ca\u653e\u81ea\u5df1\u6301\u6709\u7684\u6570\u636e\u5e93\u8fde\u63a5\uff0c\u4f46\u4e8b\u52a1\u521b\u5efa\u7684\u672a\u5173\u95ed<code>Stmt<\/code>\u4ecd\u7136\u4fdd\u7559\u7740\u5bf9\u4e8b\u52a1\u8fde\u63a5\u7684\u5f15\u7528\u3002\u5728\u4e8b\u52a1\u7ed3\u675f\u540e\u6267\u884c<code>stmt.Close()<\/code>\uff0c\u5982\u679c\u539f\u6765\u91ca\u653e\u7684\u8fde\u63a5\u5df2\u7ecf\u88ab\u5176\u4ed6\u67e5\u8be2\u83b7\u53d6\u5e76\u4f7f\u7528\uff0c\u5c31\u4f1a\u4ea7\u751f\u7ade\u4e89\uff0c\u6781\u6709\u53ef\u80fd\u7834\u574f\u8fde\u63a5\u7684\u72b6\u6001\u3002<\/p>\n<h2 id=\"18\">6. \u5904\u7406\u7a7a\u503c<\/h2>\n<p>\u53ef\u7a7a\u5217\uff08Nullable Column\uff09\u975e\u5e38\u7684\u607c\u4eba\uff0c\u5bb9\u6613\u5bfc\u81f4\u4ee3\u7801\u53d8\u5f97\u4e11\u964b\u3002\u5982\u679c\u53ef\u4ee5\uff0c\u5728\u8bbe\u8ba1\u65f6\u5c31\u5e94\u5f53\u5c3d\u91cf\u907f\u514d\u3002\u56e0\u4e3a\uff1a<\/p>\n<ul>\n<li>Go\u8bed\u8a00\u7684\u6bcf\u4e00\u4e2a\u53d8\u91cf\u90fd\u6709\u7740\u9ed8\u8ba4\u96f6\u503c\uff0c\u5f53\u6570\u636e\u7684\u96f6\u503c\u6ca1\u6709\u610f\u4e49\u65f6\uff0c\u53ef\u4ee5\u7528\u96f6\u503c\u6765\u8868\u793a\u7a7a\u503c\u3002\u4f46\u5f88\u591a\u60c5\u51b5\u4e0b\uff0c\u6570\u636e\u7684\u96f6\u503c\u548c\u7a7a\u503c\u5b9e\u9645\u4e0a\u6709\u7740\u4e0d\u540c\u7684\u8bed\u4e49\u3002\u5355\u72ec\u7684\u539f\u5b50\u7c7b\u578b\u65e0\u6cd5\u8868\u793a\u8fd9\u79cd\u60c5\u51b5\u3002<\/li>\n<li>\u6807\u51c6\u5e93\u53ea\u63d0\u4f9b\u4e86\u6709\u9650\u7684\u56db\u79cd<code>Nullable type<\/code>\uff1a\uff1a<code>NullInt64, NullFloat64, NullString, NullBool<\/code>\u3002\u5e76\u6ca1\u6709\u8bf8\u5982<code>NullUint64<\/code>\uff0c<code>NullYourFavoriteType<\/code>\uff0c\u7528\u6237\u9700\u8981\u81ea\u5df1\u5b9e\u73b0\u3002<\/li>\n<li>\u7a7a\u503c\u6709\u5f88\u591a\u9ebb\u70e6\u7684\u5730\u65b9\u3002\u4f8b\u5982\u7528\u6237\u8ba4\u4e3a\u67d0\u4e00\u5217\u4e0d\u4f1a\u51fa\u73b0\u7a7a\u503c\u800c\u91c7\u7528\u57fa\u672c\u7c7b\u578b\u63a5\u6536\u65f6\u5374\u9047\u5230\u4e86\u7a7a\u503c\uff0c\u7a0b\u5e8f\u5c31\u4f1a\u5d29\u6e83\u3002\u8fd9\u79cd\u9519\u8bef\u975e\u5e38\u7a00\u5c11\uff0c\u96be\u4ee5\u6355\u6349\u3001\u4fa6\u6d4b\u3001\u5904\u7406\uff0c\u751a\u81f3\u610f\u8bc6\u5230\u3002<\/li>\n<\/ul>\n<h3 id=\"19\">\u7a7a\u503c\u7684\u89e3\u51b3\u529e\u6cd5<\/h3>\n<h4 id=\"20\">\u4f7f\u7528\u989d\u5916\u7684\u6807\u8bb0\u5b57\u6bb5<\/h4>\n<p><code>database\\sql<\/code>\u63d0\u4f9b\u4e86\u56db\u79cd\u57fa\u672c\u53ef\u7a7a\u6570\u636e\u7c7b\u578b\uff1a\u4f7f\u7528\u57fa\u672c\u7c7b\u578b\u548c\u4e00\u4e2a\u5e03\u5c14\u6807\u8bb0\u7684\u590d\u5408\u7ed3\u6784\u4f53\u8868\u793a\u53ef\u7a7a\u503c\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code class=\"go hljs coffeescript\">type NullInt64 struct {\r\n        Int64 int64\r\n        Valid bool <span class=\"hljs-regexp\">\/\/<\/span> Valid <span class=\"hljs-keyword\">is<\/span> <span class=\"hljs-literal\">true<\/span> <span class=\"hljs-keyword\">if<\/span> Int64 <span class=\"hljs-keyword\">is<\/span> <span class=\"hljs-keyword\">not<\/span> NULL\r\n}<\/code><\/pre>\n<p>\u53ef\u7a7a\u7c7b\u578b\u7684\u4f7f\u7528\u65b9\u6cd5\u4e0e\u57fa\u672c\u7c7b\u578b\u4e00\u81f4\uff1a<\/p>\n<pre><code class=\"go hljs cs\"><span class=\"hljs-keyword\">for<\/span> rows.Next() {\r\n    <span class=\"hljs-keyword\">var<\/span> s sql.NullString\r\n    err := rows.Scan(&amp;s)\r\n    <span class=\"hljs-comment\">\/\/ check err<\/span>\r\n    <span class=\"hljs-keyword\">if<\/span> s.Valid {\r\n       <span class=\"hljs-comment\">\/\/ use s.String<\/span>\r\n    } <span class=\"hljs-keyword\">else<\/span> {\r\n       <span class=\"hljs-comment\">\/\/ handle NULL case<\/span>\r\n    }\r\n}<\/code><\/pre>\n<h4 id=\"21\">\u4f7f\u7528\u6307\u9488<\/h4>\n<p>\u5728Java\u4e2d\u901a\u8fc7\u88c5\u7bb1\uff08boxing\uff09\u5904\u7406\u53ef\u7a7a\u7c7b\u578b\uff0c\u5373\u628a\u57fa\u672c\u7c7b\u578b\u5305\u88c5\u6210\u4e00\u4e2a\u7c7b\uff0c\u5e76\u901a\u8fc7\u6307\u9488\u5f15\u7528\u3002\u4e8e\u662f\uff0c\u7a7a\u503c\u8bed\u4e49\u53ef\u4ee5\u901a\u8fc7\u6307\u9488\u4e3a\u7a7a\u6765\u8868\u793a\u3002Go\u5f53\u7136\u4e5f\u53ef\u4ee5\u91c7\u7528\u8fd9\u79cd\u529e\u6cd5\uff0c\u4e0d\u8fc7\u6807\u51c6\u5e93\u4e2d\u5e76\u6ca1\u6709\u63d0\u4f9b\u8fd9\u79cd\u5b9e\u73b0\u65b9\u5f0f\u3002<code>pgx<\/code>\u63d0\u4f9b\u4e86\u8fd9\u79cd\u5f62\u5f0f\u7684\u53ef\u7a7a\u7c7b\u578b\u652f\u6301\u3002<\/p>\n<h4 id=\"22\">\u4f7f\u7528\u96f6\u503c\u8868\u793a\u7a7a\u503c<\/h4>\n<p>\u5982\u679c\u6570\u636e\u672c\u8eab\u4ece\u8bed\u4e49\u4e0a\u5c31\u4e0d\u4f1a\u51fa\u73b0\u96f6\u503c\uff0c\u6216\u8005\u6839\u672c\u4e0d\u533a\u5206\u96f6\u503c\u548c\u7a7a\u503c\uff0c\u90a3\u4e48\u6700\u7b80\u4fbf\u7684\u65b9\u6cd5\u5c31\u662f\u4f7f\u7528\u96f6\u503c\u6765\u8868\u793a\u7a7a\u503c\u3002\u9a71\u52a8<code>go-pg<\/code>\u63d0\u4f9b\u4e86\u8fd9\u79cd\u5f62\u5f0f\u7684\u652f\u6301\u3002<\/p>\n<h4 id=\"23\">\u81ea\u5b9a\u4e49\u5904\u7406\u903b\u8f91<\/h4>\n<p>\u4efb\u4f55\u5b9e\u73b0\u4e86<code>Scanner<\/code>\u63a5\u53e3\u7684\u7c7b\u578b\uff0c\u90fd\u53ef\u4ee5\u4f5c\u4e3a<code>Scan<\/code>\u4f20\u5165\u7684\u5730\u5740\u53c2\u6570\u7c7b\u578b\u3002\u8fd9\u5c31\u5141\u8bb8\u7528\u6237\u81ea\u5df1\u5b9a\u5236\u590d\u6742\u7684\u89e3\u6790\u903b\u8f91\uff0c\u5b9e\u73b0\u66f4\u4e30\u5bcc\u7684\u7c7b\u578b\u652f\u6301\u3002<\/p>\n<pre><code class=\"go hljs cs\">type Scanner <span class=\"hljs-keyword\">interface<\/span> {\r\n          <span class=\"hljs-comment\">\/\/ Scan \u4ece\u6570\u636e\u5e93\u9a71\u52a8\u4e2d\u626b\u63cf\u51fa\u4e00\u4e2a\u503c\uff0c\u5f53\u4e0d\u80fd\u65e0\u635f\u5730\u8f6c\u6362\u65f6\uff0c\u5e94\u5f53\u8fd4\u56de\u9519\u8bef<\/span>\r\n          <span class=\"hljs-comment\">\/\/ src\u53ef\u80fd\u662fint64, float64, bool, []byte, string, time.Time\uff0c\u4e5f\u53ef\u80fd\u662fnil\uff0c\u8868\u793a\u7a7a\u503c\u3002<\/span>\r\n        Scan(src <span class=\"hljs-keyword\">interface<\/span>{}) error\r\n}<\/code><\/pre>\n<h4 id=\"24\">\u5728\u6570\u636e\u5e93\u5c42\u9762\u89e3\u51b3<\/h4>\n<p>\u901a\u8fc7\u5bf9\u5217\u6dfb\u52a0<code>NOT NULL<\/code>\u7ea6\u675f\uff0c\u53ef\u4ee5\u786e\u4fdd\u4efb\u4f55\u7ed3\u679c\u90fd\u4e0d\u4f1a\u4e3a\u7a7a\u3002\u6216\u8005\uff0c\u901a\u8fc7\u5728<code>SQL<\/code>\u4e2d\u4f7f\u7528<code>COALESCE<\/code>\u6765\u4e3aNULL\u8bbe\u5b9a\u9ed8\u8ba4\u503c\u3002<\/p>\n<h2 id=\"25\">7. \u5904\u7406\u52a8\u6001\u5217<\/h2>\n<p><code>Scan()<\/code>\u51fd\u6570\u8981\u6c42\u4f20\u9012\u7ed9\u5b83\u7684\u76ee\u6807\u53d8\u91cf\u7684\u6570\u76ee\uff0c\u4e0e\u7ed3\u679c\u96c6\u4e2d\u7684\u5217\u6570\u6b63\u597d\u5339\u914d\uff0c\u5426\u5219\u5c31\u4f1a\u51fa\u9519\u3002<\/p>\n<p>\u4f46\u603b\u6709\u4e00\u4e9b\u60c5\u51b5\uff0c\u7528\u6237\u4e8b\u5148\u5e76\u4e0d\u77e5\u9053\u8fd4\u56de\u7684\u7ed3\u679c\u5230\u5e95\u6709\u591a\u5c11\u5217\uff0c\u4f8b\u5982\u8c03\u7528\u4e00\u4e2a\u8fd4\u56de\u8868\u7684\u5b58\u50a8\u8fc7\u7a0b\u65f6\u3002<\/p>\n<p>\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u4f7f\u7528<code>rows.Columns()<\/code>\u6765\u83b7\u53d6\u5217\u540d\u5217\u8868\u3002\u5728\u4e0d\u77e5\u9053\u5217\u7c7b\u578b\u60c5\u51b5\u4e0b\uff0c\u5e94\u5f53\u4f7f\u7528<code>sql.RawBytes<\/code>\u4f5c\u4e3a\u63a5\u53d7\u53d8\u91cf\u7684\u7c7b\u578b\u3002\u83b7\u53d6\u7ed3\u679c\u540e\u81ea\u884c\u89e3\u6790\u3002<\/p>\n<pre><code class=\"hljs cs\">cols, err := rows.Columns()\r\n<span class=\"hljs-keyword\">if<\/span> err != nil {\r\n    <span class=\"hljs-comment\">\/\/ handle this....<\/span>\r\n}\r\n\r\n<span class=\"hljs-comment\">\/\/ \u76ee\u6807\u5217\u662f\u4e00\u4e2a\u52a8\u6001\u751f\u6210\u7684\u6570\u7ec4<\/span>\r\ndest := []<span class=\"hljs-keyword\">interface<\/span>{}{\r\n    <span class=\"hljs-keyword\">new<\/span>(<span class=\"hljs-keyword\">string<\/span>),\r\n    <span class=\"hljs-keyword\">new<\/span>(uint32),\r\n    <span class=\"hljs-keyword\">new<\/span>(sql.RawBytes),\r\n}\r\n\r\n<span class=\"hljs-comment\">\/\/ \u5c06\u6570\u7ec4\u4f5c\u4e3a\u53ef\u53d8\u53c2\u6570\u4f20\u5165Scan\u4e2d\u3002<\/span>\r\nerr = rows.Scan(dest...)\r\n<span class=\"hljs-comment\">\/\/ ...<\/span>\r\n<\/code><\/pre>\n<h2 id=\"26\">8. \u8fde\u63a5\u6c60<\/h2>\n<p><code>database\/sql<\/code>\u5305\u91cc\u5b9e\u73b0\u4e86\u4e00\u4e2a\u901a\u7528\u7684\u8fde\u63a5\u6c60\uff0c\u5b83\u53ea\u63d0\u4f9b\u4e86\u975e\u5e38\u7b80\u5355\u7684\u63a5\u53e3\uff0c\u9664\u4e86\u9650\u5236\u8fde\u63a5\u6570\u3001\u8bbe\u7f6e\u751f\u547d\u5468\u671f\u57fa\u672c\u6ca1\u6709\u4ec0\u4e48\u5b9a\u5236\u9009\u9879\u3002\u4f46\u4e86\u89e3\u5b83\u7684\u4e00\u4e9b\u7279\u6027\u4e5f\u662f\u5f88\u6709\u5e2e\u52a9\u7684\u3002<\/p>\n<ul>\n<li>\u8fde\u63a5\u6c60\u610f\u5473\u7740\uff1a\u540c\u4e00\u4e2a\u6570\u636e\u5e93\u4e0a\u7684\u8fde\u7eed\u4e24\u6761\u67e5\u8be2\u53ef\u80fd\u4f1a\u6253\u5f00\u4e24\u4e2a\u8fde\u63a5\uff0c\u5728\u5404\u81ea\u7684\u8fde\u63a5\u4e0a\u6267\u884c\u3002\u8fd9\u53ef\u80fd\u5bfc\u81f4\u4e00\u4e9b\u8ba9\u4eba\u56f0\u60d1\u7684\u9519\u8bef\uff0c\u4f8b\u5982\u7a0b\u5e8f\u5458\u5e0c\u671b\u9501\u8868\u63d2\u5165\u65f6\u8fde\u7eed\u6267\u884c\u4e86\u4e24\u6761\u547d\u4ee4\uff1a<code>LOCK TABLE<\/code>\u548c<code>INSERT<\/code>\uff0c\u7ed3\u679c\u5374\u4f1a\u963b\u585e\u3002\u56e0\u4e3a\u6267\u884c\u63d2\u5165\u65f6\uff0c\u8fde\u63a5\u6c60\u521b\u5efa\u4e86\u4e00\u4e2a\u65b0\u7684\u8fde\u63a5\uff0c\u800c\u8fd9\u6761\u8fde\u63a5\u5e76\u6ca1\u6709\u6301\u6709\u8868\u9501\u3002<\/li>\n<li>\u5728\u9700\u8981\u65f6\uff0c\u800c\u4e14\u8fde\u63a5\u6c60\u4e2d\u6ca1\u6709\u53ef\u7528\u7684\u8fde\u63a5\u65f6\uff0c\u8fde\u63a5\u624d\u88ab\u521b\u5efa\u3002<\/li>\n<li>\u9ed8\u8ba4\u60c5\u51b5\u4e0b\u8fde\u63a5\u6570\u91cf\u6ca1\u6709\u9650\u5236\uff0c\u60f3\u521b\u5efa\u591a\u5c11\u5c31\u6709\u591a\u5c11\u3002\u4f46\u670d\u52a1\u5668\u5141\u8bb8\u7684\u8fde\u63a5\u6570\u5f80\u5f80\u662f\u6709\u9650\u7684\u3002<\/li>\n<li>\u7528<code>db.SetMaxIdleConns(N)<\/code>\u6765\u9650\u5236\u8fde\u63a5\u6c60\u4e2d\u7a7a\u95f2\u8fde\u63a5\u7684\u6570\u91cf\uff0c\u4f46\u662f\u8fd9\u5e76\u4e0d\u4f1a\u9650\u5236\u8fde\u63a5\u6c60\u7684\u5927\u5c0f\u3002\u8fde\u63a5\u56de\u6536(recycle)\u7684\u5f88\u5feb\uff0c\u901a\u8fc7\u8bbe\u7f6e\u4e00\u4e2a\u8f83\u5927\u7684N\uff0c\u53ef\u4ee5\u5728\u8fde\u63a5\u6c60\u4e2d\u4fdd\u7559\u4e00\u4e9b\u7a7a\u95f2\u8fde\u63a5\uff0c\u4f9b\u5feb\u901f\u590d\u7528(reuse)\u3002\u4f46\u4fdd\u6301\u8fde\u63a5\u7a7a\u95f2\u65f6\u95f4\u8fc7\u4e45\u53ef\u80fd\u4f1a\u5f15\u53d1\u5176\u4ed6\u95ee\u9898\uff0c\u6bd4\u5982\u8d85\u65f6\u3002\u8bbe\u7f6e<code>N=0<\/code>\u5219\u53ef\u4ee5\u907f\u514d\u8fde\u63a5\u7a7a\u95f2\u592a\u4e45\u3002<\/li>\n<li>\u7528<code>db.SetMaxOpenConns(N)<\/code>\u6765\u9650\u5236\u8fde\u63a5\u6c60\u4e2d<strong>\u6253\u5f00<\/strong>\u7684\u8fde\u63a5\u6570\u91cf\u3002<\/li>\n<li>\u7528<code>db.SetConnMaxLifetime(d time.Duration)<\/code>\u6765\u9650\u5236\u8fde\u63a5\u7684\u751f\u547d\u5468\u671f\u3002\u8fde\u63a5\u8d85\u65f6\u540e\uff0c\u4f1a\u5728\u9700\u8981\u65f6\u60f0\u6027\u56de\u6536\u590d\u7528\u3002<\/li>\n<\/ul>\n<p>\u200b<\/p>\n<h2 id=\"27\">9. \u5fae\u5999\u884c\u4e3a<\/h2>\n<p><code>database\/sql<\/code>\u5e76\u4e0d\u590d\u6742\uff0c\u4f46\u67d0\u4e9b\u60c5\u51b5\u4e0b\u5b83\u7684\u5fae\u5999\u8868\u73b0\u4ecd\u7136\u4f1a\u51fa\u4eba\u610f\u6599\u3002<\/p>\n<h3 id=\"28\">9.1 \u8d44\u6e90\u8017\u5c3d<\/h3>\n<p>\u4e0d\u8c28\u614e\u5730\u4f7f\u7528<code>database\/sql<\/code>\u4f1a\u7ed9\u81ea\u5df1\u6316\u8bb8\u591a\u5751\uff0c\u6700\u5e38\u89c1\u7684\u95ee\u9898\u5c31\u662f\u8d44\u6e90\u67af\u7aed\uff08resource exhaustion\uff09\uff1a<\/p>\n<ul>\n<li>\u6253\u5f00\u548c\u5173\u95ed\u6570\u636e\u5e93\uff08<code>sql.DB<\/code>\uff09\u53ef\u80fd\u4f1a\u5bfc\u81f4\u8d44\u6e90\u67af\u7aed\uff1b<\/li>\n<li>\u7ed3\u679c\u96c6\u6ca1\u6709\u8bfb\u53d6\u5b8c\u6bd5\uff0c\u6216\u8005\u8c03\u7528<code>rows.Close()<\/code>\u5931\u8d25\uff0c\u7ed3\u679c\u96c6\u4f1a\u4e00\u76f4\u5360\u7528\u6c60\u91cc\u7684\u8fde\u63a5\uff1b<\/li>\n<li>\u4f7f\u7528<code>Query()<\/code>\u6267\u884c\u4e00\u4e9b\u4e0d\u8fd4\u56de\u7ed3\u679c\u96c6\u7684\u8bed\u53e5\uff0c\u8fd4\u56de\u7684\u672a\u8bfb\u53d6\u7ed3\u679c\u96c6\u4f1a\u4e00\u76f4\u5360\u7528\u6c60\u91cc\u7684\u8fde\u63a5\uff1b<\/li>\n<li>\u4e0d\u4e86\u89e3\u51c6\u5907\u8bed\u53e5\uff08Prepared Statement\uff09\u7684\u5de5\u4f5c\u539f\u7406\u4f1a\u4ea7\u751f\u8bb8\u591a\u989d\u5916\u7684\u6570\u636e\u5e93\u8bbf\u95ee\u3002<\/li>\n<\/ul>\n<h3 id=\"29\">9.2 Uint64<\/h3>\n<p>Go\u5e95\u5c42\u4f7f\u7528<code>int64<\/code>\u6765\u8868\u793a\u6574\u578b\uff0c\u4f7f\u7528<code>uint64<\/code>\u65f6\u5e94\u5f53\u6781\u5176\u5c0f\u5fc3\u3002\u4f7f\u7528\u8d85\u51fa<code>int64<\/code>\u8868\u793a\u8303\u56f4\u7684\u6574\u6570\u4f5c\u4e3a\u53c2\u6570\uff0c\u4f1a\u4ea7\u751f\u4e00\u4e2a\u6ea2\u51fa\u9519\u8bef\uff1a<\/p>\n<pre><code class=\"go hljs sql\">\/\/ Error: constant 18446744073709551615 overflows int\r\n_, err := db.Exec(\"<span class=\"hljs-keyword\">INSERT<\/span> <span class=\"hljs-keyword\">INTO<\/span> <span class=\"hljs-keyword\">users<\/span>(<span class=\"hljs-keyword\">id<\/span>) <span class=\"hljs-keyword\">VALUES<\/span><span class=\"hljs-string\">\", math.MaxUint64) <\/span><\/code><\/pre>\n<p>\u8fd9\u79cd\u7c7b\u578b\u7684\u9519\u8bef\u975e\u5e38\u4e0d\u5bb9\u6613\u53d1\u73b0\uff0c\u5b83\u53ef\u80fd\u4e00\u5f00\u59cb\u8868\u73b0\u7684\u5f88\u6b63\u5e38\uff0c\u4f46\u662f\u6ea2\u51fa\u4e4b\u540e\u95ee\u9898\u5c31\u6765\u4e86\u3002<\/p>\n<h3 id=\"30\">9.3 \u4e0d\u5408\u9884\u671f\u7684\u8fde\u63a5\u72b6\u6001<\/h3>\n<p>\u8fde\u63a5\u7684\u72b6\u6001\uff0c\u4f8b\u5982\u662f\u5426\u5904\u4e8e\u4e8b\u52a1\u4e2d\uff0c\u6240\u8fde\u63a5\u7684\u6570\u636e\u5e93\uff0c\u8bbe\u7f6e\u7684\u53d8\u91cf\u7b49\uff0c\u5e94\u8be5\u901a\u8fc7Go\u7684\u76f8\u5173\u7c7b\u578b\u6765\u5904\u7406\uff0c\u800c\u4e0d\u662f\u901a\u8fc7SQL\u8bed\u53e5\u3002\u7528\u6237\u4e0d\u5e94\u5f53\u5bf9\u81ea\u5df1\u7684\u67e5\u8be2\u5728\u54ea\u6761\u8fde\u63a5\u4e0a\u6267\u884c\u4f5c\u4efb\u4f55\u5047\u8bbe\uff0c\u5982\u679c\u9700\u8981\u5728\u540c\u4e00\u6761\u8fde\u63a5\u4e0a\u6267\u884c\uff0c\u9700\u8981\u4f7f\u7528<code>Tx<\/code>\u3002<\/p>\n<p>\u4e3e\u4e2a\u4f8b\u5b50\uff0c\u901a\u8fc7<code>USE DATABASE<\/code>\u6539\u53d8\u8fde\u63a5\u7684\u6570\u636e\u5e93\u5bf9\u4e8e\u4e0d\u5c11\u4eba\u662f\u4e60\u4ee5\u4e3a\u5e38\u7684\u64cd\u4f5c\uff0c\u6267\u884c\u8fd9\u6761\u8bed\u53e5\uff0c\u53ea\u5f71\u54cd\u5f53\u524d\u8fde\u63a5\u7684\u72b6\u6001\uff0c\u5176\u4ed6\u8fde\u63a5\u4ecd\u7136\u8bbf\u95ee\u7684\u662f\u539f\u6765\u7684\u6570\u636e\u5e93\u3002\u5982\u679c\u6ca1\u6709\u4f7f\u7528\u4e8b\u52a1<code>Tx<\/code>\uff0c\u540e\u7eed\u7684\u67e5\u8be2\u5e76\u4e0d\u80fd\u4fdd\u8bc1\u4ecd\u7136\u7531\u5f53\u524d\u7684\u8fde\u63a5\u6267\u884c\uff0c\u6240\u4ee5\u8fd9\u4e9b\u67e5\u8be2\u5f88\u53ef\u80fd\u5e76\u4e0d\u50cf\u7528\u6237\u9884\u671f\u7684\u90a3\u6837\u5de5\u4f5c\u3002<\/p>\n<p>\u66f4\u7cdf\u7cd5\u7684\u662f\uff0c\u5982\u679c\u7528\u6237\u6539\u53d8\u4e86\u8fde\u63a5\u7684\u72b6\u6001\uff0c\u7528\u5b8c\u4e4b\u540e\u5b83\u6210\u4e3a\u7a7a\u8fde\u63a5\u53c8\u56de\u5230\u4e86\u8fde\u63a5\u6c60\uff0c\u8fd9\u4f1a\u6c61\u67d3\u5176\u4ed6\u4ee3\u7801\u7684\u72b6\u6001\u3002\u5c24\u5176\u662f\u76f4\u63a5\u5728SQL\u4e2d\u6267\u884c\u8bf8\u5982<code>BEGIN<\/code>\u6216<code>COMMIT<\/code>\u8fd9\u6837\u7684\u8bed\u53e5\u3002<\/p>\n<h3 id=\"31\">9.4 \u9a71\u52a8\u7684\u7279\u6b8a\u8bed\u6cd5<\/h3>\n<p>\u5c3d\u7ba1<code>database\/sql<\/code>\u662f\u4e00\u4e2a\u901a\u7528\u7684\u62bd\u8c61\uff0c\u4f46\u4e0d\u540c\u7684\u6570\u636e\u5e93\uff0c\u4e0d\u540c\u7684\u9a71\u52a8\u4ecd\u7136\u4f1a\u6709\u4e0d\u540c\u7684\u8bed\u6cd5\u548c\u884c\u4e3a\u3002\u53c2\u6570\u5360\u4f4d\u7b26\u5c31\u662f\u4e00\u4e2a\u4f8b\u5b50\u3002<\/p>\n<h3 id=\"32\">9.5 \u6279\u91cf\u64cd\u4f5c<\/h3>\n<p>\u51fa\u4e4e\u610f\u6599\u7684\u662f\uff0c\u6807\u51c6\u5e93\u6ca1\u6709\u63d0\u4f9b\u5bf9\u6279\u91cf\u64cd\u4f5c\u7684\u652f\u6301\u3002\u5373<code>INSERT INTO xxx VALUES (1),(2),...;<\/code>\u8fd9\u79cd\u4e00\u6761\u8bed\u53e5\u63d2\u5165\u591a\u6761\u6570\u636e\u7684\u5f62\u5f0f\u3002\u76ee\u524d\u5b9e\u73b0\u8fd9\u4e2a\u529f\u80fd\u8fd8\u9700\u8981\u81ea\u5df1\u624b\u52a8\u62fcSQL\u3002<\/p>\n<h3 id=\"33\">9.6 \u6267\u884c\u591a\u6761\u8bed\u53e5<\/h3>\n<p><code>database\/sql<\/code>\u5e76\u6ca1\u6709\u5bf9\u5728\u4e00\u6b21\u67e5\u8be2\u4e2d\u6267\u884c\u591a\u6761SQL\u8bed\u53e5\u7684\u663e\u5f0f\u652f\u6301\uff0c\u5177\u4f53\u7684\u884c\u4e3a\u4ee5\u9a71\u52a8\u7684\u5b9e\u73b0\u4e3a\u51c6\u3002\u6240\u4ee5\u5bf9\u4e8e<\/p>\n<pre><code class=\"go hljs sql\">_, err := db.Exec(\"<span class=\"hljs-keyword\">DELETE<\/span> <span class=\"hljs-keyword\">FROM<\/span> tbl1; <span class=\"hljs-keyword\">DELETE<\/span> <span class=\"hljs-keyword\">FROM<\/span> tbl2<span class=\"hljs-string\">\") \/\/ Error\/unpredictable result<\/span><\/code><\/pre>\n<p>\u8fd9\u6837\u7684\u67e5\u8be2\uff0c\u600e\u6837\u6267\u884c\u5b8c\u5168\u7531\u9a71\u52a8\u8bf4\u4e86\u7b97\uff0c\u7528\u6237\u5e76\u65e0\u6cd5\u786e\u5b9a\u9a71\u52a8\u5230\u5e95\u6267\u884c\u4e86\u4ec0\u4e48\uff0c\u53c8\u8fd4\u56de\u4e86\u4ec0\u4e48\u3002<\/p>\n<h3 id=\"34\">9.7 \u4e8b\u52a1\u4e2d\u7684\u591a\u6761\u8bed\u53e5<\/h3>\n<p>\u56e0\u4e3a\u4e8b\u52a1\u4fdd\u8bc1\u5728\u5b83\u4e0a\u9762\u6267\u884c\u7684\u67e5\u8be2\u90fd\u7531\u540c\u4e00\u4e2a\u8fde\u63a5\u6765\u6267\u884c\uff0c\u56e0\u6b64\u4e8b\u52a1\u4e2d\u7684\u8bed\u53e5\u5fc5\u9700\u6309\u987a\u5e8f\u4e00\u6761\u4e00\u6761\u6267\u884c\u3002\u5bf9\u4e8e\u8fd4\u56de\u7ed3\u679c\u96c6\u7684\u67e5\u8be2\uff0c\u7ed3\u679c\u96c6\u5fc5\u987b<code>Close()<\/code>\u4e4b\u540e\u624d\u80fd\u8fdb\u884c\u4e0b\u4e00\u6b21\u67e5\u8be2\u3002\u7528\u6237\u5982\u679c\u5c1d\u8bd5\u5728\u524d\u4e00\u6761\u8bed\u53e5\u7684\u7ed3\u679c\u8fd8\u6ca1\u8bfb\u5b8c\u524d\u5c31\u6267\u884c\u65b0\u7684\u67e5\u8be2\uff0c\u8fde\u63a5\u5c31\u4f1a\u5931\u53bb\u540c\u6b65\u3002\u8fd9\u610f\u5473\u7740\u4e8b\u52a1\u4e2d\u8fd4\u56de\u7ed3\u679c\u96c6\u7684\u8bed\u53e5\u90fd\u4f1a\u5360\u7528\u4e00\u6b21\u5355\u72ec\u7684\u7f51\u7edc\u5f80\u8fd4\u3002<\/p>\n<h2 id=\"35\">10. \u5176\u4ed6<\/h2>\n<p>\u672c\u6587\u4e3b\u4f53\u57fa\u4e8e[[Go database\/sql tutorial]]([Go database\/sql tutorial])\uff0c\u7531\u6211\u7ffb\u8bd1\u5e76\u8fdb\u884c\u4e00\u4e9b\u589e\u5220\u6539\uff0c\u4fee\u6b63\u8fc7\u65f6\u9519\u8bef\u7684\u5185\u5bb9\u3002\u8f6c\u8f7d\u4fdd\u7559\u51fa\u5904\u3002<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u6458\u8981\uff1a\u00a0Go\u4f7f\u7528SQL\u4e0e\u7c7bSQL\u6570\u636e\u5e93\u7684<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"colormag_page_container_layout":"default_layout","colormag_page_sidebar_layout":"default_layout","footnotes":""},"categories":[],"tags":[122],"class_list":["post-3152","post","type-post","status-publish","format-standard","hentry","tag-06-godocker"],"_links":{"self":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/3152","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/comments?post=3152"}],"version-history":[{"count":0,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/3152\/revisions"}],"wp:attachment":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/media?parent=3152"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/categories?post=3152"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/tags?post=3152"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}