Node.js MySQL 按子句排序

简介：我们使用 SQL ORDER BY 子句对数据按升序或降序对某个列值进行排序。

句法：

SELECT * FROM users ORDER BY name;
This will sort all rows of output in ascending order (by default) with respect to name column.

SELECT address FROM users ORDER BY name DESC;
This will sort all rows of output in descending order with respect to name column but return the data of address.

模块安装：使用以下命令安装mysql模块：

npm install mysql

数据库：我们的带有示例数据的 SQL用户表预览如下所示：

示例 1：从 users 表中选择所有列，但按名称按升序对它们进行排序。

index.js

const mysql = require("mysql");
  
let db_con  = mysql.createConnection({
    host: "localhost",
    user: "root",
    password: '',
    database: 'gfg_db'
});
  
db_con.connect((err) => {
    if (err) {
      console.log("Database Connection Failed !!!", err);
      return;
    }
  
    console.log("We are connected to gfg_db database");
  
    // Our Query
    let query = 'SELECT * FROM users ORDER BY name';
  
    db_con.query(query, (err, rows) => {
        if(err) throw err;
  
        console.log(rows);
    });
});

使用以下命令运行index.js文件：

node index.js

输出：

示例 2：仅从 users 表中选择地址列，但按名称降序排列。

index.js

const mysql = require("mysql");
  
let db_con  = mysql.createConnection({
    host: "localhost",
    user: "root",
    password: '',
    database: 'gfg_db'
});
  
db_con.connect((err) => {
    if (err) {
      console.log("Database Connection Failed !!!", err);
      return;
    }
  
    console.log("We are connected to gfg_db database");
  
    // Notice the address column and DESC below
    let query = 'SELECT address FROM users ORDER BY name DESC';
  
    db_con.query(query, (err, rows) => {
        if(err) throw err;
  
        console.log(rows);
    });
});

使用以下命令运行index.js文件：

node index.js

输出：