MReC66pX

1
2'use strict'
3
4var sqlite = require('sqlite3').verbose();
5var db = new sqlite.Database('test_db');
6
7db.getAsync = function (sql) {
8    var that = this;
9    return new Promise(function (resolve, reject) {
10        that.get(sql, function (err, row) {
11            if (err)
12                reject(err);
13            else
14                resolve(row);
15        });
16    });
17};
18
19db.allAsync = function (sql) {
20    var that = this;
21    return new Promise(function (resolve, reject) {
22        that.all(sql, function (err, rows) {
23            if (err)
24                reject(err);
25            else
26                resolve(rows);
27        });
28    });
29};
30
31db.runAsync = function (sql) {
32    var that = this;
33    return new Promise(function (resolve, reject) {
34        that.run(sql, function(err) {
35            if (err)
36                reject(err);
37            else
38                resolve();
39        });
40    })
41};
42
43async function voteAsync(voter) {
44    var val;
45    var getStmt = `SELECT Name, Count FROM Voters WHERE Name="${voter}"`;
46    console.log(getStmt);
47    var row = await db.getAsync(getStmt);
48    if (!row) {
49        console.log("VOTER NOT FOUND");
50        var insertSql = `INSERT INTO Voters (Name, Count) VALUES ("${voter}", 1)`;
51        console.log(insertSql);
52        await db.runAsync(insertSql);
53        val = 1;
54        return;
55    }
56    else {
57        val = row["Count"];
58        console.log(`COUNT = ${val}`);
59        val += 1;
60
61        // update
62        var updateSql = `UPDATE Voters SET Count = ${val} WHERE Name = "${voter}"`;
63        console.log(updateSql);
64        await db.runAsync(updateSql);
65    }
66
67    console.log(`RETURN ${val}`);
68    return val;
69}
70
71console.log('sqlite3...');
72async function main() {
73    try {
74        var stmt = "CREATE TABLE IF NOT EXISTS Voters (Name TEXT, Count int)";
75        console.log(stmt);
76        await db.runAsync(stmt);
77        var val = await voteAsync("john doe");
78        console.log(`New vote for John Doe is ${val}`);
79    } 
80    catch (e) {
81        console.log(JSON.stringify(ex));
82    }
83}
84
85main()