How to read a sqlite3 database, using node js, synchronously? - json

Question

exports.allProbes = function() {
var rows = db.all("SELECT * FROM probes;");
return rows;
};
main:
var json_values = allProbes();
Is it possible to do something like that?
I mean, without using a callback function: just, read data (sync mode) from the db. and return a json formatted output?
Thanks.

Answer 1

There are a few npm packages such as better-sqlite3 and sqlite-sync that allow for synchronous SQLite queries. Here's an example:
var sqlite = require("better-sqlite3");
var db = new sqlite("example.db");
var rows = db.prepare("SELECT * FROM probes").all();
console.log(rows);

Answer 2

You will not be able to do that with sqlite3. With sqlite3 module the only available mode of operation is asynchronous execution, and you will have to use a callback. Eg.
exports.allProbes = function(callback) {
db.all("SELECT * FROM probes;", function(err, all) {
callback(err, all);
});
};
Then in your code:
var json_values;
allProbes(function(err, all) {
json_values = all;
});
Check sqlite3 API Docs.

Answer 3

You have to install sql.js with npm install --save sql.js
Rest follow the below steps :
var fs = require('fs');
var sql = require('sql.js');
var bfr = fs.readFileSync('/tmp/db.sqlite');
var db = new sql.Database(bfr);
db.each('SELECT * FROM test', function (row) {
console.log(row);
});
More details you can get on the below this link : https://discuss.atom.io/t/how-to-access-a-local-db-on-windows-through-electron/22400/13