Node.js MySQL Limit

Limit 结果

您可以使用 "LIMIT" 语句限制查询返回的记录数:

实例

选择 “customers” 表中的前 5 条记录:

var mysql = require('mysql');
var con = mysql.createConnection({
 host: "localhost",
 user: "yourusername",
 password: "yourpassword",
 database: "mydb"
});
con.connect(function(err) {
 if (err) throw err;
  var sql = "SELECT * FROM customers <strong>LIMIT 5</strong>";
  con.query(sql, function (err, result) {
   if (err) throw err;
  console.log(result);
 });
 });

将上述代码保存在名为 "demo_db_limit.js" 的文件中，然后运行该文件:

运行 "demo_db_limit.js"

C:\Users\ Your Name >node demo_db_limit.js

结果如下:

[
 { id: 1, name: 'John', address: 'Highway 71'},
 { id:  2, name: 'Peter', address: 'Lowstreet 4'},
 { id: 3, name: 'Amy',  address: 'Apple st 652'},
 { id: 4, name: 'Hannah', address:  'Mountain 21'},
 { id: 5, name: 'Michael', address: 'Valley 345'}
]

从另一个位置开始取数据

如果要从第 3 条记录开始返回 5 条记录，可以使用 "OFFSET" 关键字:

实例

从位置 3 开始，返回接下来的 5 条记录:

var mysql = require('mysql');
var con = mysql.createConnection({
 host: "localhost",
 user: "yourusername",
 password: "yourpassword",
 database: "mydb"
});
con.connect(function(err) {
 if (err) throw err;
  var sql = "SELECT * FROM customers <strong>LIMIT 5 OFFSET 2</strong>";
  con.query(sql, function (err, result) {
   if (err) throw err;
  console.log(result);
 });
 });

将上述代码保存在名为 "demo_db_offset.js" 的文件中，然后运行该文件:

运行 "demo_db_offset.js"

C:\Users\ Your Name >node demo_db_offset.js

结果如下:

[
 { id: 3, name: 'Amy',  address: 'Apple st 652'},
 { id: 4, name: 'Hannah', address:  'Mountain 21'},
 { id: 5, name: 'Michael', address: 'Valley 345'},
 { id: 6, name: 'Sandy', address: 'Ocean blvd 2'},
 { id: 7, name: 'Betty',  address: 'Green Grass 1'}
]

简写语法

您还可以像下面这样写 SQL 语句 "LIMIT 2, 5"，它返回与上面的 offset 示例相同的结果:

实例

从位置 3 开始，返回接下来的 5 条记录:

var mysql = require('mysql');
var con = mysql.createConnection({
 host: "localhost",
 user: "yourusername",
 password: "yourpassword",
 database: "mydb"
});
con.connect(function(err) {
 if (err) throw err;
  var sql = "SELECT * FROM customers <strong>LIMIT 2, 5</strong>";
  con.query(sql, function (err, result) {
   if (err) throw err;
  console.log(result);
 });
 });