ionic 3 sqlite - How to execute requests from files - sqlite

Question

I am currently developing a mobile app with ionic. On this application there is a local sqlite database.
I am looking to be able to execute queries from files for possible updates of the database.
For example, when you first install the application, the tables are created if they do not exist. If changes are made to these tables after installing the application, the changes are not taken into account.
I would like to create files which can be executed one by one according to PRAGMA user_version.
Something like :
// Get pragma user version, if it's undefined, it's set to 1.
// If user_version < 1, we execute the sql file, then we update the user_version
// to 1.
db.executeSql(`PRAGMA user_version;`, []).then((res)=> {
if(res.rows.item(0).user_version < 1) {
db.sqlBatch(`app/sqlFiles/1.sql`, []).then((res)=>{
console.log(res);
}, (err) => {
console.log("Error : " + JSON.stringify(err));
});
db.executeSql(`PRAGMA user_version = 1;`, []).then((res)=>{
console.log(res);
}, (err) => {
console.log("Error : " + JSON.stringify(err));
});
}
}, (err) => {
console.log("Error : " + JSON.stringify(err));
});
I thought about using a file reader but the file is not found during the execution of the function.
this.fileOpener.open('assets/SQLFile/1.sql', 'text/plain')
.then((file) => {
var reader = new FileReader();
reader.onloadend = function(evt) {
console.log("read success");
console.log(evt.target);
};
db.sqlBatch(reader.readAsText(file)).then((res)=>{
console.log(res);
}, (err) => {
console.log("Error : " + JSON.stringify(err));
});
console.log('File is opened');
})
.catch(e => console.log('Error opening file', e));
Will anyone have an idea for doing this kind of thing? (I am looking for a solution that respects good programming practices).
Please note that I am a beginner with ionic and sqlite
Thank you in advance !

Answer 1

But you're getting an error or what? Since the post seems to be valid but the implementation seems to be a little off.
After reading the file, storing the content into a variable, you should execute that "sql query" as usually.
Nevertheless it's not a secure way of do that.
When something in your app change due to an update or upgrade, wouldn't be easier and safer to specify that into the code instead of a single file containing all the database info and scheme?
Edited:
If you want to add custom files to deployment, check this out https://ionicframework.com/docs/developer-resources/app-scripts/