node の SQLite

node operation SQLite

Before doing electron When making tomato clock application on the desktop, I thought about using database to store data , At first

mongodb

, But it is found that no server can be realized , Then only use

SQLite

了 .

Introduce ：SQLite  It's a software library , It's self-sufficient 、 serverless 、 Zero configuration 、 transactional  SQL  Database engine .SQLite  It's the most widely deployed in the world  SQL  Database engine .SQLite  Source code is not restricted by copyright

Now let's try to use node To operate

SQLite

install sqlite3 library

From the previous Introduction , You can know ,sqlite It is an installation free database , Therefore, to use the database here, you only need to add one

node

Of

sqlite3

Library will do .

Installation command ：

yarn add sqlite3 -D

establish sqlite database

Current node There is no... In the project address sqlite database , So you can create a database by using the command , Use here

new sqlite3.Database

To connect to the database ,

If there is no , Will automatically create a database

, And different from the previous operation

mongodb

, There is no need to create a collection .

const path = require('path');
const sqlite3 = require('sqlite3');

function SQLiteInit() {
 let rootPath = path.join(__dirname, '../sqlite3.db');

 let db = new sqlite3.Database(rootPath, (err)=>{
 if (err) throw err;
 console.log(' Database connection ')
 })
}

effect ：

Create a table and insert data

With the database , You need to create a database table

You can create a sql Statement execution method , This method can be achieved by

db.run

Method to run data sql sentence

//  perform sql sentence
function runSQL(sqlstr) {
 db.serialize(()=>{
 db.run(sqlstr);
 })
}

Create data table worker

let db = null;
function SQLiteInit() {
 //  Connect to database
 let rootPath = path.join(__dirname, '../sqlite3.db');
 db = new sqlite3.Database(rootPath)
 //  Create a table
 runSQL(`
 create table worker 
 (
 name text not null,
 age int not null,
 hobby text not null
 );
 `)
 //  Close the connection
 db.close();
}

Now the database tables worker It already exists .

The next operation is to insert data into the table , Here you can use

db.run

To insert... At one time , It can also be done through

prepare

To insert... Step by step .

let doc = [{
 name: ' Zhang San ',
 age: 18,
 hobby: ' Hit Li Si ',
 },
 {
 name: ' Li Si ',
 age: 18,
 hobby: ' Beat Wang Wu ',
 },
 {
 name: ' Wang Wu ',
 age: 18,
 hobby: ' Open three ',
 },
]
let insertInfo = db.prepare('insert into worker (name, age, hobby) values (?, ?, ?)')
doc.forEach((item)=>{
 insertInfo.run(item.name, item.age, item.hobby);
})
insertInfo.finalize();

Now the data has been inserted into the database

vs code

Of

sqlite

plug-in unit

For the database , It is best to use a visual interface to operate , General pair

sqlite

Are recommended navicate http://www.navicat.com.cn/

But I'm here for quick operation , No need , stay

vs code

among , There are also plug-ins that can be used to

sqlite

Simple operation of database . The name of the plug-in is

SQLite

After installing the plug-in , If you want to open the

sqlite3.db

database , Need to use

Ctrl+Shift+P

Open the command panel , Then input

sqlite

, find

Open Database

Options on .

This will show up in the left explorer interface

SQLITE EXPLORER

Here you can view the previously created

sqlite3.db

Tables in the database , Select Create... On the right

New Query

Will create a

.sql

File for execution sql Commands and statements

Write query table command ：

-- SQLite
select * from worker

Right click to select the database and run this query

Next, query the data 、 Delete and update operations are similar to insert , In fact, the main thing is sqlite Statement writing , I won't go into details here