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Start at both ends
You can limit the number of records returned from the query, by using the "LIMIT" statement:
Select the 5 first records in the "customers" table:
let mysql = require('mysql');
let con = mysql.createConnection({
host: "localhost", user: "yourusername", password: "yourpassword", database: "mydb"
});
con.connect(function(err) {
if (err) throw err;
let sql = "SELECT * FROM customers";
con.query(sql, function (err, result) {
if (err) throw err;
console.log(result);
});
});
Save the code above in a file called "demo_db_limit.js" and run the file:
Run "demo_db_limit.js"C:\Users\
>node demo_db_limit.js Which will give you this result: [
{ 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'}]
If you want to return five records, starting from the third record, you can use the "OFFSET" keyword:
Start from position 3, and return the next 5 records:
let mysql = require('mysql');
let con = mysql.createConnection({
host: "localhost", user: "yourusername", password: "yourpassword", database: "mydb"
});
con.connect(function(err) {
if (err) throw err;
let sql = "SELECT * FROM customers";
con.query(sql, function (err, result) {
if (err) throw err;
console.log(result);
});
});"OFFSET 2", means starting from the third position, not the second! Save the code above in a file called "demo_db_offset.js" and run the file: Run "demo_db_offset.js" C:\Users\
>node demo_db_offset.js Which will give you this result: [
{ 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'}]
You can also write your SQL statement like this "LIMIT 2, 5" which returns the same as the offset example above:
Start from position 3, and return the next 5 records:
let mysql = require('mysql');
let con = mysql.createConnection({
host: "localhost", user: "yourusername", password: "yourpassword", database: "mydb"
});
con.connect(function(err) {
if (err) throw err;
let sql = "SELECT * FROM customersLIMIT 2, 5
";
con.query(sql, function (err, result) {
if (err) throw err;
console.log(result);
});
});The numbers are reversed: "LIMIT 2, 5" is the same as "LIMIT 5 OFFSET 2"