使用 NodeJS 更新 MySQL 中的记录
在本文中,我们将看到如何使用 NodeJS 更新 MySQL 中的记录。我们将从 Node.js 服务器动态更新 MySQL 表值。您可以在更新后使用 select 语句来检查 MySql 记录是否已更新。
在继续之前,请检查以下步骤是否已执行 –
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MKDIR MySQL测试版
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CD MySQL测试版
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npm init -y
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npm install mysql
上述步骤用于在项目文件夹中安装 Node – mysql 依赖项。
将记录填充到学生表中 –
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要将现有记录更新到 MySQL 表中,首先创建一个 app.js 文件
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现在将以下代码片段复制粘贴到文件中
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使用以下命令运行代码
>> node app.js
例
// Checking the MySQL dependency in NPM var mysql = require('mysql'); // Creating a mysql connection var con = mysql.createConnection({ host: "localhost", user: "yourusername", password: "yourpassword", database: "mydb" }); con.connect(function(err) { if (err) throw err; var sql = "UPDATE student SET address = 'Bangalore' WHERE name = 'John';" con.query(sql, function (err, result) { if (err) throw err; console.log(result.affectedRows + " Record(s) updated."); console.log(result); }); });
输出
1 Record(s) updated. OkPacket { fieldCount: 0, affectedRows: 1, // This will return the number of rows updated. insertId: 0, serverStatus: 34, warningCount: 0, message: '(Rows matched: 1 Changed: 1 Warnings: 0', // This will return the number of rows matched. protocol41: true, changedRows: 1 }
例
// Checking the MySQL dependency in NPM var mysql = require('mysql'); // Creating a mysql connection var con = mysql.createConnection({ host: "localhost", user: "yourusername", password: "yourpassword", database: "mydb" }); con.connect(function(err) { if (err) throw err; // Updating the fields with address while checking the address var sql = "UPDATE student SET address = 'Bangalore' WHERE address = 'Delhi';" con.query(sql, function (err, result) { if (err) throw err; console.log(result.affectedRows + " Record(s) updated."); console.log(result); }); });
输出
3 Record(s) updated. OkPacket { fieldCount: 0, affectedRows: 3, // This will return the number of rows updated. insertId: 0, serverStatus: 34, warningCount: 0, message: '(Rows matched: 3 Changed: 3 Warnings: 0', // This will return the number of rows matched. protocol41: true, changedRows: 3 }
本文来自博客园,作者:很酷的站长,转载请注明原文链接:https://www.cnblogs.com/10zhan/p/17010628.html